CN117397078A

CN117397078A - Electrode assembly including current limiter, secondary battery having such electrode assembly, and test method

Info

Publication number: CN117397078A
Application number: CN202280038853.7A
Authority: CN
Inventors: M·J·阿姆斯特朗; D·J·内勒; R·S·布萨卡; B·A·瓦尔德斯; R·K·罗森; M·拉马苏布拉马尼安; A·拉希里; R·M·斯伯特尼茨
Original assignee: Enovix Corp
Current assignee: Enovix Corp
Priority date: 2021-03-31
Filing date: 2022-03-22
Publication date: 2024-01-12

Abstract

An electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range between minus 20 degrees celsius (°c) and 80 ℃ includes a unit cell population, a current limiter population, an electrode bus, and a counter electrode bus. Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure. At least one member of the current limiter group is electrically connected between the unit cell and the electrode bus bar or the counter electrode bus bar. For each unit cell, the at least one member of the current limiter group has a resistance when the electrode assembly is within the normal operating temperature range sufficient to limit current through the unit cell to less than a threshold current I that is less than a current that would induce thermal runaway of the unit cell.

Description

Electrode assembly including current limiter, secondary battery having such electrode assembly, and test method

Cross Reference to Related Applications

The present application claims priority from U.S. provisional patent application serial No. 63/168,430, filed 3/31 at 2021, and U.S. provisional patent application serial No. 63/202,922, filed 6/30 at 2021, the entire disclosures of which are hereby incorporated by reference.

Technical Field

The field of the present disclosure relates generally to energy storage technology, such as battery technology. More particularly, the field of the present disclosure relates to electrode assemblies including current limiters and secondary batteries having such electrode assemblies.

Background

Secondary batteries, such as lithium-based secondary batteries, have become a desirable energy source due to their relatively high energy density, power and shelf life. Examples of the lithium secondary battery include nonaqueous electrolyte batteries such as lithium ions and lithium polymer batteries.

Known energy storage devices, such as batteries, fuel cell units and electrochemical capacitors, typically have a two-dimensional layered architecture, such as a planar or spiral wound (i.e., jellyroll) laminate structure, wherein the surface area of each laminate is approximately equal to its geometric footprint (ignoring porosity and surface roughness).

Fig. 1 shows a cross-sectional view of a known secondary battery of the laminar type, generally indicated at 10. The battery 10 includes a positive current collector 15 in contact with a positive electrode 20. Negative electrode 25 is separated from positive electrode 20 by separator 30. Negative electrode 25 is in contact with a negative electrode current collector 35. As shown in fig. 1, the cells 10 are formed in a stack. The stack is sometimes covered with another separator layer (not shown) over the negative current collector 35, and then wound and placed into a can (not shown) to assemble the battery 10. During the charging process, carrier ions (typically lithium) leave positive electrode 20 and pass through separator 30 into negative electrode 25. Depending on the anode material used, the carrier ions are embedded in the alloy (e.g., located in the matrix of the anode material without forming an alloy) or form an alloy with the anode material. During the discharge process, the carrier ions leave the negative electrode 25 and return through the separator 30 and back into the positive electrode 20.

The three-dimensional secondary battery may provide increased capacity and lifetime as compared to the layered secondary battery. Three-dimensional battery architectures (e.g., interdigitated electrode arrays) have been proposed in the literature to provide higher electrode surface area, higher energy and power density, improved battery capacity, and improved active material utilization compared to two-dimensional architectures (e.g., flat and spiral laminates). For example, references to Long et al, "Three-dimensional Battery architecture (Three-dimensional battery architectures)", "Chemical Reviews", 2004,104,4463-4492 may help illustrate the state of the art in the proposed Three-dimensional battery architecture, and are therefore incorporated herein by reference as a non-essential subject matter.

There is a risk that: energy storage devices, including secondary batteries, may release energy in an undesirable or uncontrolled manner due to accidents, abuse, exposure to extreme conditions, and the like. The construction of safety features into secondary batteries can reduce this risk and improve abuse tolerance.

The safety of current lithium-based batteries may be compromised by various mechanisms, many of which are related by temperature rise phenomena. At overcharging and high operating temperatures, overheating and thermal runaway may occur due to electrolyte decomposition. In the case of high voltage cathode materials such as LiCoO2, thermal runaway may also occur due to oxygen evolution. In some cases, mechanical abuse may also cause the active materials to short together, thereby causing thermal runaway. This may be due to battery overcharge, electrical shorting, or mechanical abuse-related shorting. The rapid release of heat during chemical reactions involving electrolyte or cathode decomposition may increase the risk of thermal runaway in conventional two-dimensional batteries.

Self-stopping devices, such as polymers or ceramic materials with positive temperature coefficients of resistance (PTC), have been used to enhance the safety of conventional two-dimensional batteries. Such materials are sometimes referred to as restorable fuses or self-regulating thermostats. Other systems have been proposed that incorporate non-resettable or sacrificial fuses that melt to mechanically create an open circuit that interrupts the flow of excess current through the battery. For example, references to P.G.Balakrishnan, R.Ramesh and t.prem Kumar, "safety mechanisms in lithium ion batteries (Safety mechanisms in lithium-ion batteries)", "journal of energy (Journal of Power Sources), 2006,155,401-414 may help illustrate the state of the art of safety mechanisms in conventional lithium ion batteries, and are therefore incorporated herein by reference as a non-essential subject matter.

In at least some known lithium-based secondary batteries, resettable or non-resettable fuses have a measurable hysteresis between the flow of an overcurrent and tripping of the fuse. This hysteresis occurs because the fuse is typically activated by heat generated when an overcurrent flows through the battery. Thus, in the case of a non-resettable fuse, an overcurrent will flow through the battery for a period of time until the temperature experienced by the fuse reaches the temperature required to melt the fuse, or in the case of a resettable fuse using PTC materials, the resistance is increased sufficiently to limit the current flowing through the battery. In some cases, hysteresis between the onset of overcurrent and tripping of the fuse may cause the fuse to fail to prevent thermal runaway.

In addition, the non-resettable fuse permanently breaks at least a portion of the battery when the fuse trips. Thus, even if the fuse prevents thermal runaway and catastrophic failure, the battery will not operate at all or will operate with only a limited capacity.

It is therefore desirable to create a three-dimensional battery that includes a current limiter to limit the current that may flow through the battery independent of the temperature of the battery, thereby solving the problems in the prior art.

Disclosure of Invention

In one embodiment, a method of assembling an electrode assembly includes stacking groups of unit cell units on top of each other in a stacking direction. Each member of the unit cell group includes an electrode structure including an electrode current collector and an electrode active material layer, a separator structure including a counter electrode current collector and a counter electrode active material layer, and a counter electrode structure extending in a longitudinal direction perpendicular to the stacking direction, and an end portion of the electrode current collector extending beyond the electrode active material and the separator structure in the longitudinal direction. The method includes bending the end portion of each electrode current collector in a direction orthogonal to the longitudinal direction of the electrode structure and extending in the stacking direction or in a direction opposite to the stacking direction. An electrode buss is positioned to extend in the stacking direction, with a surface of the electrode buss adjacent to the end portion of the electrode current collector. Heat and pressure are applied to the electrode buss to adhere the end portion of the electrode current collector to the buss by an adhesive layer comprising a resistive polymer material.

In another embodiment, an electrode assembly for cycling between a charged state and a discharged state includes a group of unit cells,Electrode bus, counter electrode bus and current limiter group. Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group has a capacity C and includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer. For each member of the group of unit battery cells, (a) the electrode collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) a member of the group of current limiters is electrically connected between (i) the electrode collector and the electrode bus bar or (ii) the counter electrode collector and the counter electrode bus bar. Each member of the unit cell group has a maximum charge voltage (top of charge voltage) V between the electrode collector and the counter electrode collector _TOC And has a unit cell resistance R determined at a non-zero frequency between the electrode collector and the counter electrode collector _bl . Each member of the current limiter group has a resistance R _cld The resistance limits the amount of current that can be conducted from the electrode or the counter electrode buss to a member of a group of unit cells during discharge of the electrode assembly in which there is an electrical short between the electrode and the counter electrode of one member of the group of unit cells to a value I determined according to the following equation:

R _S hard short resistance as determined using a dry Forced Internal Short (FISC) test, R, which is a member of a unit cell group _t Is the combined resistance of the electrode bus and the counter electrode bus determined at the non-zero frequency, and R _cld Having a non-zero value such that:

I _c *R _cld <0.5 volt

Wherein I is _c Is the 1C current rate.

In another embodiment, an electrode assembly for cycling between a charged state and a discharged state includes a unit cell population, a current limiter population, an electrode buss, and a counter electrode buss. Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer. For each member of the group of unit battery cells, (a) the electrode current collectors of the electrode structures are electrically connected to the electrode bus bars, (b) the counter electrode current collectors of the counter electrode structures are electrically connected to the counter electrode bus bars, and (c) members of the group of current limiters are located in the electrical connection between (i) the electrode current collectors and the electrode bus bars or (ii) the counter electrode current collectors and the counter electrode bus bars. Each member of the current limiter group includes a conductive adhesive having a resistance at 25 degrees celsius (°c) of greater than or equal to 0.25 ohms (Ω).

In another embodiment, an electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range between minus 20 degrees celsius (°c) and 80 ℃, the electrode assembly comprising a unit cell population, a current limiter population, an electrode bus, and a counter electrode bus. Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer. For each member of the group of unit battery cells, (a) the electrode current collectors of the electrode structures are electrically connected to the electrode bus bars, (b) the counter electrode current collectors of the counter electrode structures are electrically connected to the counter electrode bus bars, and (c) at least one member of the group of current limiters is electrically connected between (i) the electrode current collectors and the electrode bus bars or (ii) the counter electrode current collectors and the counter electrode bus bars. For each unit cell, the at least one member of the current limiter group has a resistance when the electrode assembly is within the normal operating temperature range sufficient to limit current through the unit cell to less than a threshold current I that is less than a current that would induce thermal runaway of the unit cell.

Various refinements exist of the features noted in relation to the above-noted aspects. Other features may also be incorporated in the above aspects as well. These refinements and additional features may exist individually or in any combination. For example, the various features discussed below with respect to any of the illustrated embodiments may be incorporated into any of the above aspects, alone or in any combination.

Drawings

Fig. 1 is a cross section of a conventional layered battery.

Fig. 2 is a simplified diagram of an example electrode assembly for cycling between a charged state and a discharged state in a secondary battery.

Fig. 3A is a simplified view of an end of a counter electrode current collector of the electrode assembly of fig. 2.

Fig. 3B is a view of the end portion of the counter electrode collector in fig. 3A connected to the counter electrode bus bar.

Fig. 4A is a top view of a pair of electrode structures of the electrode assembly of fig. 2, wherein current collectors of the pair of electrode structures are attached to a bus bar by a current limiter.

Fig. 4B is a side view of one of the electrode structures of fig. 4A, wherein the current collector of the electrode structure is attached to the bus bar by a current limiter.

Fig. 5 is a simplified diagram of another example electrode assembly for cycling between a charged state and a discharged state in a secondary battery.

Fig. 6 is a schematic diagram of yet another example electrode assembly for cycling between a charged state and a discharged state in a secondary battery.

Fig. 7 is a simplified diagram of still another example electrode assembly for cycling between a charged state and a discharged state in a secondary battery.

Fig. 8A is a simplified isometric view of an anode electrode structure for use in an electrode assembly.

Fig. 8B is a simplified isometric view of a cathode electrode structure for use in an electrode assembly.

Fig. 9 is an isometric view of an example stacked battery cell produced as part of the manufacture of a secondary battery.

Fig. 10 is a portion of a top view of the stacked battery cell shown in fig. 9.

Fig. 11A is an isometric view of the stacked battery cell shown in fig. 9 positioned at a packaging station.

Fig. 11B is an isometric view of the stacked battery cell shown in fig. 11A with a battery package placed thereon.

Fig. 12 is a simplified diagram of a unit cell of an electrode assembly tested in a forced internal short circuit test.

Fig. 13 is a simplified diagram of a portion of another example electrode assembly for cycling between a charged state and a discharged state in a secondary battery.

Fig. 14 is a side view of an electrode structure with current collectors attached to the bus bars by current limiters and interface layers applied to the bus bars.

Fig. 15 is a side view of an electrode structure with current collectors attached to bus bars by current limiters and interface layers applied to the electrode current collectors.

Fig. 16 is a side view of an electrode structure with current collectors attached to bus bars by current limiters, interface layers applied to the current electrode current collectors, and interface layers applied to the bus bars.

Fig. 17 is a side view of a counter electrode current collector connected to a counter electrode bus bar without the use of slots in the current collector.

Fig. 18 is a side view of one of the electrode structures, with the current collector of the electrode structure attached to the bus bar by a current limiter formed as a single layer without using a slot in the current collector.

Fig. 19 is a side view of one of the electrode structures with the current collector of the electrode structure attached to the bus bar by discrete current limiters formed as a single layer without the use of slots in the current collector.

Corresponding reference characters indicate corresponding parts throughout the drawings.

Definition of the definition

As used herein, "a," "an," and "the" (i.e., singular forms) refer to the plural referents unless the context clearly dictates otherwise. For example, in one example, reference to "an electrode" includes both a single electrode and a plurality of like electrodes.

As used herein, "about" and "about" refer to ±10%, 5% or 1% of the value. For example, in one example, about 250 μm will comprise 225 μm to 275 μm. Further by way of example, in one example, about 1,000 μm will comprise 900 μm to 1,100 μm. Unless otherwise indicated, all numbers expressing quantities (e.g., measurement, etc.) and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations. Each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

An "anode" as used herein in the context of a secondary battery refers to a negative electrode in the secondary battery.

As used herein, "anode material" or "anode activity" refers to a material suitable for use as a negative electrode of a secondary battery.

The "cathode" as used herein in the context of a secondary battery refers to the positive electrode in the secondary battery.

As used herein, "cathode material" or "cathode activity" refers to a material suitable for use as the positive electrode of a secondary battery.

"conversion chemical active material" or "conversion chemical material" refers to a material that undergoes chemical reactions during charge and discharge cycles of a secondary battery.

As used herein, a "counter electrode" may refer to the negative or positive electrode (anode or cathode) of a secondary battery opposite the electrode, unless the context clearly indicates otherwise.

As used herein, a "counter electrode current collector" may refer to a negative or positive (anode or cathode) current collector of a secondary battery opposite an electrode current connector unless the context clearly indicates otherwise.

As used herein in the context of cycling a secondary battery between a charged state and a discharged state, refers to charging and/or discharging the battery such that the battery moves from a first state of the charged state or the discharged state to a second state opposite the first state (i.e., the charged state if the first state is discharged, or the discharged state if the first state is charged) in the cycle, and then moves the battery back to the first state to complete the cycle. For example, a single cycle of the secondary battery between a charged state and a discharged state may involve charging the battery from the discharged state to the charged state as in a charging cycle, and then discharging back to the discharged state to complete the cycle. A single cycle may also involve discharging the battery from a charged state to a discharged state, as in a discharge cycle, and then charging back to the charged state to complete the cycle.

As used herein, "electrochemically active material" refers to either an anode active material or a cathode active material.

As used herein, an "electrode" may refer to a negative electrode or a positive electrode (anode or cathode) of a secondary battery unless the context clearly indicates otherwise.

As used herein, an "electrode current collector" may refer to a negative or positive (anode or cathode) current collector of a secondary battery unless the context clearly indicates otherwise.

As used herein, "electrode material" may refer to either anode material or cathode material unless the context clearly indicates otherwise.

As used herein, an "electrode structure" may refer to an anode structure (e.g., a negative electrode structure) or a cathode structure (e.g., a positive electrode structure) suitable for use in a battery unless the context clearly indicates otherwise.

As used herein, "longitudinal axis," "transverse axis," and "vertical axis" refer to axes that are perpendicular to each other (i.e., each is orthogonal to each other). For example, as used herein, "longitudinal axis," "transverse axis," and "vertical axis" are similar to a Cartesian coordinate system used to define three-dimensional aspects or orientations. Thus, descriptions of elements of the subject matter disclosed herein are not limited to one or more particular axes for describing three-dimensional orientations of the elements. Alternatively, the axes may be interchangeable when referring to three-dimensional aspects of the disclosed subject matter.

Detailed Description

Embodiments of the present disclosure relate to a battery, such as a three-dimensional secondary battery, and an electrode assembly for such a battery, including a current limiter to limit the current that can flow through the battery, thereby limiting heat increase, helping to prevent thermal runaway, and improving the safety of the battery.

Fig. 2 is a simplified diagram of an example electrode assembly 200 in a battery for cycling between a charged state and a discharged state. Electrode assembly 200 includes a group of electrode structures 202, a group of counter electrode structures 204, a group of separator structures 205, a group of current limiters 206, an electrode buss 208, and a counter electrode buss 210. The example embodiment is an electrode assembly suitable for a three-dimensional secondary battery in which the electrode structure 202 and the counter electrode structure 204 each extend mainly along the width W and the height H of the assembly and are separated from each other along the length (or longitudinal) direction L. In other embodiments, the electrode assembly 200 may be used for a layered secondary battery.

There is a voltage difference V between the adjacent electrode structure 202 and the counter electrode structure 204, which may be considered as a unit cell. Each unit cell has a capacity C determined by the composition and configuration of the electrode structure 202 and the counter electrode structure 204. In an example embodiment, each unit cell generates a voltage difference of about 4.35 volts. In other embodiments, the voltage difference for each unit cell is about 0.5 volts, about 1.0 volts, about 1.5 volts, about 2.0 volts, about 2.5 volts, about 3.0 volts, about 3.5 volts, about 4.0 volts, 4.5 volts, about 5.0 volts, between 4 volts and 5 volts, or any other suitable voltage. During the cycle between charging and discharging, the voltage may vary, for example, between about 2.5 volts and about 4.35 volts. The capacity C of the unit cell in the exemplary embodiment is about 25mAh. In other embodiments, the unit cell capacity C is about 50mAh, less than 50mAh, or any other suitable capacity. In some embodiments, the capacity C of the unit cell may be at most about 500mAh.

In an example embodiment, the electrode structures 202 and the counter electrode structures 204 are generally rectangular and are arranged in an interdigitated structure. That is, the electrode structures 202 and the counter electrode structures 204 extend from opposite electrode busses 208 and 210 and alternate along the length direction L. In other embodiments, other shapes and arrangements of the electrode structure 202 and the counter electrode structure 204 are used. For example, the electrode assembly 200 (and the battery contained therein) may have any of the shapes and/or arrangements described or illustrated in U.S. patent 9,166,230, which is hereby incorporated by reference in its entirety.

Each member of the electrode structure population 202 comprises an electrode active material 212 and an electrode current collector 214. The electrode structures 202 are electrically connected in parallel to an electrode buss 208 through a current limiter 206. The electrode structures 202 may be anodic or cathodic, but in an example embodiment, all of the electrode structures 202 in the population are of the same type (anodic or cathodic). In some other embodiments, the electrode structure 202 may comprise an anode and a cathode structure. Each member of the population of counter electrode structures 204 comprises a counter electrode active material 216 and a counter electrode current collector 218. The counter electrode structure 204 is electrically connected in parallel to the counter electrode bus bar 210. In the example embodiment, the counter electrode structures 204 are all of the same type (anodic or cathodic) and of opposite type to the electrode structures 204. In some other embodiments, the counter electrode structure 202 may comprise an anode and cathode structure. Although only two electrode structures 202 and two counter electrode structures 204 are shown in fig. 2, the electrode assembly 200 may have any number of electrode structures 202 and counter electrode structures 204. The electrode structure group 202 and the counter electrode structure group 204 will typically contain the same number of members, but in some embodiments may contain different numbers of electrode structures 202 and counter electrode structures 204. For example, some embodiments may begin and end with the same electrode structure 202 or counter electrode structure, resulting in one more electrode structure 202 or counter electrode structure. In some embodiments, the electrode structure population 202 and the counter electrode structure population 204 each comprise at least twenty members. Some embodiments include electrode structure group 202 and counter electrode structure group 204 each having about 10 members, each having between 10 and 25 members, each having between 25 and 250 members, each having between 25 and 150 members, each having between 50 and 150 members, or each having up to 500 members. In some embodiments, electrode structure 202 or counter electrode structure 204 does not contain active material when discharged, and only the other of counter electrode structure 204 or electrode structure 202 contains active material when discharged.

The cathode type electrode structure 202 or counter electrode structure 204 includes a current collector 214 or 218 as a cathode current collector. The cathode current collector may include aluminum, nickel, cobalt, titanium, and tungsten or alloys thereof, or any other material suitable for use as a cathode current collector layer. Generally, the conductivity of the cathode current collector will be at least about 10 ³ Siemens/cm. For example, in one such embodiment, the conductivity of the cathode current collector will be at least about 10 ⁴ Siemens/cm. Further by way of example, in one such embodiment, the cathode current collector has an electrical conductivity of at least about 10 ⁵ Siemens/cm. The anode-type electrode structure 202 or the counter electrode structure 204 includes a current collector 214 or 218 as an anode current collector. The anode current collector may include a conductive material such as copper, carbon, nickel, stainless steel, cobalt, titanium, and tungsten and alloys thereof, or any other material suitable as an anode current collector layer.

The cathode type electrode structure 202 or counter electrode structure 204 contains an active material 212 or 216 as a cathode active material. The cathode active material may be an intercalation chemically active material, a conversion chemically active material, or a combination thereof.

Exemplary conversion chemistry materials useful in the present disclosure include, but are not limited to, S (or Li in a lithiated state) ₂ S)、LiF、Fe、Cu、Ni、FeF ₂ 、FeO _d F _3.2d 、FeF ₃ 、CoF ₃ 、CoF ₂ 、CuF ₂ 、NiF ₂ Wherein d is more than or equal to 0 and less than or equal to 0.5, etc.

Exemplary cathode active materials also include any of a wide range of embedded cathode active materials. For example, for a lithium ion battery, the cathode active material may include a cathode active material selected from the group consisting of: transition metal oxides, transition metal sulfides, transition metal nitrides, lithium transition metal oxides, lithium transition metal sulfides, and lithium transition metal nitrides may be selectively used. The transition metal element of the transition metal oxide, the transition metal sulfide, and the transition metal nitride may contain a metal element having a d-shell layer or an f-shell layer. Specific examples of such metallic elements are Sc, Y, lanthanoid, actinoid, ti, zr, hf, V, nb, ta, cr, mo, W, mn, tc, re, fe, ru, os, co, rh, ir, ni, pb, pt, cu, ag, and Au. The additional cathode active material comprises LiCoO ₂ 、LiNi _0.5 Mn _1.5 O ₄ 、Li(Ni _x Co _y Al _z )O ₂ 、LiFePO ₄ 、Li ₂ MnO ₄ 、V ₂ O ₅ Molybdenum oxysulfide, phosphate, silicate, vanadate, sulfur compound, oxygen (air), li (Ni) _x Mn _y Co _z )O ₂ And combinations thereof.

In general, the thickness of the cathode active material will be at least about 20um, regardless of whether the electrode structure 202 is a cathode-type structure or the counter electrode structure 204 is a cathode-type structure. For example, in one embodiment, the thickness of the cathode active material is at least about 40um. By way of further example, in one such embodiment, the thickness of the cathode active material will be at least about 60um. By way of further example, in one such embodiment, the thickness of the cathode active material will be at least about 100um. Typically, however, the thickness of the cathode active material is less than about 90um or even less than about 70um.

The anode-type electrode structure 202 or the counter electrode structure 204 contains an active material 212 or 216 as an anode active material. In general, the anode active material may be selected from the group consisting of: (a) Silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), and cadmium (Cd); (b) Si, ge, sn, pb, sb, bi, zn, al, ti, ni, co or an alloy or intermetallic compound of Cd with other elements; (c) Si, ge, sn, pb, sb, bi, zn, al, ti, fe, ni, co, V or Cd oxides, carbides, nitrides, sulfides, phosphides, selenides and tellurides, and mixtures, composites or lithium-containing composites thereof; (d) salts and hydroxides of Sn; (e) Lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxide, lithium transition metal oxide, znCo2O4; (f) particles of graphite and carbon; (g) lithium metal, and (h) combinations thereof.

Exemplary anode active materials include carbon materials such as graphite and soft or hard carbon, or graphene (e.g., single-walled or multi-walled carbon nanotubes), or any of a range of metals, semi-metals, alloys, oxides, nitrides, and compounds capable of intercalating or alloying with lithium. Specific examples of metals or semi-metals that can constitute the anode material include graphite, tin, lead, magnesium, aluminum, boron, gallium, silicon, si/C composites, si/graphite blends, silicon oxide (SiOx), porous Si, intermetallic Si alloys, indium, zirconium, germanium, bismuth, cadmium, antimony, silver, zinc, arsenic, hafnium, yttrium, lithium, sodium, graphite, carbon, lithium titanate, palladium, and mixtures thereof. In one exemplary embodiment, the anode active material includes aluminum, tin, or silicon, or an oxide thereof, a nitride thereof, a fluoride thereof, or other alloys thereof. In another exemplary embodiment, the anode active material includes silicon or an alloy or oxide thereof.

In one embodiment, the anode active material is microstructured to provide a significant void volume fraction to accommodate volume expansion and contraction as lithium ions (or other carrier ions) are incorporated into or leave the anode active material during the charging and discharging process. In general, the void volume fraction of (each of) the anode active material layers is at least 0.1. However, in general, the void volume fraction of (each of) the anode active material layers is not more than 0.8. For example, in one embodiment, the void volume fraction of (each of) the anode active material layers is about 0.15 to about 0.75. By way of further example, in one embodiment, the void volume fraction of (each of) the anode active material layers is about 0.2 to about 0.7. By way of further example, in one embodiment, the void volume fraction of (each of) the anode active material layers is about 0.25 to about 0.6.

Depending on the composition of the microstructured anode active material and the method of forming the same, the microstructured anode active material may include macropores, micropores, or mesoporous material layers, or combinations thereof, such as a combination of micropores and mesopores or a combination of mesopores and macropores. Microporous materials are generally characterized by pore sizes of less than 10nm, wall sizes of less than 10nm, pore depths of 1 to 50 microns and are generally characterized by a "spongy" and irregular appearance of pore morphology, uneven walls, and branched pores. Materials are generally characterized by pore sizes of 10 to 50nm, wall sizes of 10 to 50nm, pore depths of 1 to 100 microns and by pore morphology of somewhat well-defined branched or dendritic pores. Macroporous materials are generally characterized by a pore size greater than 50nm, a wall size greater than 50nm, a pore depth of 1 to 500 microns, and a pore morphology that may be varied, straight, branched or dendritic and smooth or rough walls. In addition, the void volume may include open voids or closed voids or a combination thereof. In one embodiment, the void volume comprises open voids, i.e., the anode active material contains voids having openings at the lateral surfaces of the anode active material through which lithium ions (or other carrier ions) can enter or leave the anode active material; for example, lithium ions may enter the anode active material through the void opening after leaving the cathode active material. In another embodiment, the void volume comprises closed voids, i.e., the anode active material contains voids that are closed by the anode active material. In general, open voids can provide a greater interfacial surface area for the carrier ions, while closed voids tend to be less sensitive to solid electrolyte interfaces, while each void provides room for the anode active material to expand as the carrier ions enter. Thus, in certain embodiments, it is preferred that the anode active material comprises a combination of open and closed voids.

In one embodiment, the anode active material comprises porous aluminum, tin, or silicon, or alloys, oxides, or nitrides thereof. The porous silicon layer may be formed, for example, by anodization, by etching (e.g., by depositing a noble metal such as gold, platinum, silver, or gold/palladium on the surface of monocrystalline silicon, and etching the surface with a mixture of hydrofluoric acid and hydrogen peroxide), or by other methods known in the art such as patterned chemical etching. In addition, the porous anode active material will typically have a porosity fraction of at least about 0.1 but less than 0.8 and a thickness of from about 1 micron to about 100 microns. For example, in one embodiment, the anode active material comprises porous silicon, the anode active material has a thickness of about 5 microns to about 100 microns, and a porosity fraction of about 0.15 microns to about 0.75. By way of further example, in one embodiment, the anode active material comprises porous silicon, the anode active material has a thickness of about 10 microns to about 80 microns, and a porosity fraction of about 0.15 to about 0.7. By way of further example, in one such embodiment, the anode active material comprises porous silicon, the anode active material has a thickness of about 20 microns to about 50 microns, and a porosity fraction of about 0.25 to about 0.6. By way of further example, in one embodiment, the anode active material comprises a porous silicon alloy (e.g., nickel silicide), the anode active material has a thickness of about 5 microns to about 100 microns, and a porosity fraction of about 0.15 microns to about 0.75.

In another embodiment, the anode active material comprises fibers of aluminum, tin, or silicon, or alloys thereof. The individual fibers may have a diameter (thickness dimension) of about 5nm to about 10,000nm and a length generally corresponding to the thickness of the anode active material. Silicon fibers (nanowires) may be formed, for example, by chemical vapor deposition or other techniques known in the art, such as vapor-liquid-solid (VLS) growth and solid-liquid-solid (SLS) growth. In addition, the anode active material will typically have a porosity fraction of at least about 0.1 but less than 0.8, and a thickness of from about 1 micron to about 200 microns. For example, in one embodiment, the anode active material comprises silicon nanowires, the anode active material has a thickness of about 5 microns to about 100 microns, and a porosity fraction of about 0.15 microns to about 0.75. By way of further example, in one embodiment, the anode active material comprises silicon nanowires, the anode active material has a thickness of about 10 microns to about 80 microns, and a porosity fraction of about 0.15 to about 0.7. By way of further example, in one such embodiment, the anode active material comprises silicon nanowires, the anode active material has a thickness of about 20 microns to about 50 microns, and a porosity fraction of about 0.25 to about 0.6. By way of further example, in one embodiment, the anode active material comprises nanowires of a silicon alloy (e.g., nickel silicide), the anode active material has a thickness of about 5 microns to about 100 microns, and a porosity fraction of about 0.15 microns to about 0.75.

In yet other embodiments, the anode negative electrode (i.e., electrode or counter electrode) is coated with a particulate lithium material selected from the group consisting of: stable lithium metal particles, for example, lithium carbonate stable lithium metal powder, lithium silicate stable lithium metal powder, or other sources of stable lithium metal powder or ink. By mixing at about 0.05mg/cm ² To 5mg/cm ² (e.g., about 0.1 mg/cm) ² To 4mg/cm ² Or even about 0.5mg/cm ² To 3mg/cm ² ) Is sprayed, supported, or otherwise disposed on the anode active material layer to apply the particulate lithium material to the anode active material layer. Average particle diameter of lithium particulate Material (D ₅₀ ) May be 5 μm to 200 μm, for example, about 10 μm to 100 μm, 20 μm to 80 μm, or even about 30 μm to 50 μm. Average particle diameter (D) ₅₀ ) Can be defined as corresponding to a particle size of 50% in the cumulative volume based particle size distribution curve. The average particle diameter (D can be measured, for example, using a laser diffraction method ₅₀ )。

The anode-type electrode structure 202 or the counter electrode structure 204 includes a current collector 214 or 218 as an anode current collector. Generally, the conductivity of the anode current collector will be at least about 10 ³ Siemens/cm. For example, in one such embodiment, the conductivity of the anode current collector will be at least about 10 ⁴ Siemens/cm. Further by way of example, in one such embodiment, the anode current collector has an electrical conductivity of at least about 10 ⁵ Siemens/cm. Exemplary conductive materials suitable for use as the anode current collector include metals such as copper, nickel, cobalt, titanium, and tungsten, and alloys thereof.

In one embodiment, the electrical conductivity of the anode current collector (i.e., which of the electrode current collector 214 or the counter electrode current collector 218 is of the anode type) is substantially greater than the electrical conductivity of its associated electrode or counter electrode active material 212, 216. For example, in one embodiment, the ratio of the electrical conductivity of the anode current collector to the electrical conductivity of the anode active material is at least 100:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the conductivity of the anode current collector to the conductivity of the anode active material is at least 500:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the conductivity of the anode current collector to the conductivity of the anode active material is at least 1000:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the conductivity of the anode current collector to the conductivity of the anode active material layer is at least 5000:1 when there is an applied current to store energy in the device or an applied load to discharge the device. By way of further example, in some embodiments, the ratio of the conductivity of the anode current collector to the conductivity of the anode active material is at least 10,000:1 when there is an applied current to store energy in the device or an applied load to discharge the device.

In general, the cathode-type current collector (i.e., either electrode current collector 214 or counter electrode current collector 218 is of the cathode type) may include metals such as aluminum, carbon, chromium, gold, nickel, niP, palladium, platinum, rhodium, ruthenium, alloys of silicon and nickel, titanium, or combinations thereof (see a.h. whitehead and m.schreiber, "current collector for positive electrode of lithium-based batteries (Current collectors for positive electrodes of lithium-based batteries)", "journal of electrochemical society (Journal of the Electrochemical Society), 152 (11) a2105-a2113 (2005)). By way of further example, in one embodiment, the cathode current collector comprises gold or an alloy thereof, such as gold silicide. By way of further example, in one embodiment, the cathode current collector comprises nickel or an alloy thereof, such as nickel silicide.

Referring to fig. 8A, each anode electrode structure (i.e., each electrode structure 202 or counter electrode structure 204 of the anode type) has a longitudinal axis (a _E ) Length of measurement (L _E ) Width (W) _E ) In a direction orthogonal to the length L _E And width W _E Height (H) measured in the direction of each of the measured directions of (2) _E )。

Length L of member of anode electrode structure group _E Will vary depending on the energy storage device and its intended use. However, in general, the length L of the anode electrode structure _E Typically will be in the range of about 5mm to about 500 mm. For example, in one such embodiment, the length L of the anode electrode structure _E From about 10mm to about 250mm. Further for example, in one such embodiment, the length L of a member of the anode population _E From about 25mm to about 100mm. According to one embodiment, an anode electrode structure includes one or more first electrode members having a first length and one or more second electrode members having a second length different from the first length. In yet another embodiment, the different lengths of the one or more first electrode members and the one or more second electrode members may be selected to accommodate a predetermined shape of the electrode assembly, such as an electrode assembly shape having different lengths along one or more of the longitudinal and/or transverse axes, and/or to provide predetermined performance characteristics for the secondary battery.

Width W of anode electrode structure _E Will also be based on energy storageThe device varies with its intended use. However, in general, the width W of each anode electrode structure _E Typically will be in the range of about 0.01mm to 2.5 mm. For example, in one embodiment, the width W of each anode electrode structure _E Will be in the range of about 0.025mm to about 2 mm. Further by way of example, in one embodiment, the width W of each anode electrode structure _E Will be in the range of about 0.05mm to about 1 mm. According to one embodiment, an anode electrode structure includes one or more first electrode members having a first width and one or more second electrode members having a second width different from the first width. In yet another embodiment, the different widths of the one or more first electrode members and the one or more second electrode members may be selected to accommodate a predetermined shape of the electrode assembly, such as an electrode assembly shape having different widths along one or more of the longitudinal and/or transverse axes, and/or to provide predetermined performance characteristics for the secondary battery.

Height H of anode electrode structure _E Will also vary depending on the energy storage device and its intended use. However, in general, the height H of the anode electrode structure _E Typically will be in the range of about 0.05mm to about 25 mm. For example, in one embodiment, the height H of each anode electrode structure _E Will be in the range of about 0.05mm to about 5 mm. Further by way of example, in one embodiment, the height H of each anode electrode structure _E Will be in the range of about 0.1mm to about 1 mm. According to one embodiment, an anode electrode structure includes one or more first electrode members having a first height and one or more second electrode members having a second height different from the first height. In yet another embodiment, the different heights of the one or more first electrode members and the one or more second electrode members may be selected to accommodate a predetermined shape of the electrode assembly, such as an electrode assembly shape having different heights along one or more of the longitudinal and/or transverse axes, and/or to provide predetermined performance characteristics for the secondary battery.

In general, the length L of the anode electrode structure _E Significantly greater than the width W of the anode electrode structure _E And the height W of the anode electrode structure _E Each of which is a single-phase alternating current power supply. For example, in one embodiment, L for each member of the anode population _E And W is equal to _E And H _E The ratio of each of (a) is at least 5:1 (i.e., L _E And W is equal to _E Is at least 5:1, and L _E And H is _E At least 5:1, respectively). Further for example, in one embodiment, L _E And W is equal to _E And H _E Is at least 10:1. Further for example, in one embodiment, L _E And W is equal to _E And H _E Is at least 15:1. Further for example, in one embodiment, for each member of the anode population, L _E And W is equal to _E And H _E Is at least 20:1.

In one embodiment, the height H of the anode electrode structure _E And width W _E The ratio of (2) is at least 0.4:1, respectively. For example, in one embodiment, for each member of the anode population, H _E And W is equal to _E Will be at least 2:1, respectively. Further by way of example, in one embodiment, H _E And W is equal to _E Will be at least 10:1, respectively. Further by way of example, in one embodiment, H _E And W is equal to _E Will be at least 20:1, respectively. However, in general, H _E And W is equal to _E Will typically be less than 1,000:1, respectively. For example, in one embodiment, H _E And W is equal to _E Will be less than 500:1, respectively. Further by way of example, in one embodiment, H _E And W is equal to _E Will be less than 100:1, respectively. Further by way of example, in one embodiment, H _E And W is equal to _E Will be less than 10:1, respectively. Further by way of example, in one embodiment, for each member of the anode electrode structure population, H _E And W is equal to _E Will be in the range of about 2:1 to about 100:1, respectively.

Referring to fig. 8B, each cathode electrode structure (i.e., each electrode structure 202 or counter electrode structure 204 of the cathode type) has a longitudinal axis (a _CE ) Length of measurement (L _CE ) Width (W) _CE ) In a direction perpendicular to the length L _CE And width W _CE Height (H) measured in the direction of each of the measured directions of (2) _CE )。

Length L of cathode electrode structure _CE Will vary depending on the energy storage device and its intended use. However, in general, the length L of each member of the cathode population _CE Typically will be in the range of about 5mm to about 500 mm. For example, in one such embodiment, the length L of each cathode electrode structure _CE From about 10mm to about 250mm. Further for example, in one such embodiment, the length L of each cathode electrode structure _CE From about 25mm to about 100mm. According to one embodiment, a cathode electrode structure includes one or more first electrode members having a first length and one or more second electrode members having a second length different from the first length. In yet another embodiment, the different lengths of the one or more first electrode members and the one or more second electrode members may be selected to accommodate a predetermined shape of the electrode assembly, such as an electrode assembly shape having different lengths along one or more of the longitudinal and/or transverse axes, and/or to provide predetermined performance characteristics for the secondary battery.

Width W of cathode electrode structure _CE Will also vary depending on the energy storage device and its intended use. However, in general, the width W of the cathode electrode structure _CE Typically will be in the range of about 0.01mm to 2.5 mm. For example, in one embodiment, the width W of each cathode electrode structure _CE Will be in the range of about 0.025mm to about 2 mm. Further by way of example, in one embodiment, the width W of each cathode electrode structure _CE Will be in the range of about 0.05mm to about 1 mm. According to one embodiment, a cathode electrode structure includes one or more first electrode members having a first width and one or more second electrode members having a second width different from the first width. In yet another embodiment, the different widths of the one or more first electrode members and the one or more second electrode members may be selected to accommodate electrode combinations The predetermined shape of the member, such as an electrode assembly shape having different widths along one or more of the longitudinal and/or transverse axes, and/or to provide the secondary battery with predetermined performance characteristics.

Height H of cathode electrode structure _CE Will also vary depending on the energy storage device and its intended use. However, in general, the height H of the cathode electrode structure _CE Typically will be in the range of about 0.05mm to about 25 mm. For example, in one embodiment, the height H of each cathode electrode structure _CE Will be in the range of about 0.05mm to about 5 mm. Further by way of example, in one embodiment, the height H of each cathode electrode structure _CE Will be in the range of about 0.1mm to about 1 mm. According to one embodiment, a cathode electrode structure includes one or more first cathode members having a first height and one or more second cathode members having a second height different from the first height. In yet another embodiment, the different heights of the one or more first cathode members and the one or more second cathode members may be selected to accommodate a predetermined shape of the electrode assembly, such as an electrode assembly shape having different heights along one or more of the longitudinal and/or transverse axes, and/or to provide predetermined performance characteristics for the secondary battery.

In general, the length L of each cathode electrode structure _CE Significantly greater than width W _CE And is significantly greater than the height H of the cathode electrode structure _CE . For example, in one embodiment, for each cathode electrode structure, L _CE And W is equal to _CE And H _CE The ratio of each of (a) is at least 5:1 (i.e., L _CE And W is equal to _CE Is at least 5:1, and L _CE And H is _CE At least 5:1, respectively). Further by way of example, in one embodiment, for each cathode electrode structure, L _CE And W is equal to _CE And H _CE Is at least 10:1. Further by way of example, in one embodiment, for each cathode electrode structure, L _CE And W is equal to _CE And H _CE Is at least 15:1. By way of further example, in one embodiment,for each cathode electrode structure, L _CE And W is equal to _CE And H _CE Is at least 20:1.

In one embodiment, the height H of the cathode electrode structure _CE And width W _CE The ratio of (2) is at least 0.4:1, respectively. For example, in one embodiment, for each cathode electrode structure, H _CE And W is equal to _CE Will be at least 2:1, respectively. Further by way of example, in one embodiment, for each cathode electrode structure, H _CE And W is equal to _CE Will be at least 10:1, respectively. Further by way of example, in one embodiment, for each cathode electrode structure, H _CE And W is equal to _CE Will be at least 20:1, respectively. However, typically, for each member of the anode population, H _CE And W is equal to _CE Will typically be less than 1,000:1, respectively. For example, in one embodiment, for each cathode electrode structure, H _CE And W is equal to _CE Will be less than 500:1, respectively. Further by way of example, in one embodiment, H _CE And W is equal to _CE Will be less than 100:1, respectively. Further by way of example, in one embodiment, H _CE And W is equal to _CE Will be less than 10:1, respectively. Further by way of example, in one embodiment, for each cathode electrode structure, H _CE And W is equal to _CE Will be in the range of about 2:1 to about 100:1, respectively.

Returning to fig. 2, the separator structure 205 separates the electrode structure 202 from the counter electrode structure. The diaphragm structure 205 is made of an electrically insulating but ion permeable diaphragm material. The separator structure 205 is adapted to electrically isolate each member of the electrode structure population 202 from each member of the counter electrode structure population 204. Each separator structure 205 will typically comprise a microporous separator material that is permeable to the non-aqueous electrolyte; for example, in one embodiment, the microporous separator membrane material comprises a polymer having a diameter of at least More typically at about->And porosity in the range of about 25% to about 75%, more typically in the range of about 35% to 55%.

Generally, the thickness of the electrically insulating separator material is at least about 4um. For example, in one embodiment, the thickness of the electrically insulating separator material will be at least about 8um. Further by way of example, in one such embodiment, the thickness of the electrically insulating separator material will be at least about 12um. Further by way of example, in one such embodiment, the thickness of the electrically insulating separator material will be at least about 15um. In some embodiments, the electrically insulating separator material will have a thickness of at most 25um, at most 50um, or any other suitable thickness. Typically, however, the thickness of the electrically insulating separator material will be less than about 12um or even less than about 10um.

In general, the material of the separator structure 205 may be selected from a wide range of materials having the ability to conduct carrier ions between the positive and negative active materials of the unit cell. For example, the separator structure 205 may include a microporous separator material that is permeable to liquid, non-aqueous electrolytes. Alternatively, the separator structure 205 may include a gel or solid electrolyte capable of conducting carrier ions between the positive and negative electrodes of the unit cell.

In one embodiment, the separator structure 205 can include a polymer-based electrolyte. Exemplary polymer electrolytes include PEO-based polymer electrolytes, polymer-ceramic composite electrolytes, and polymer-ceramic composite electrolytes.

In another embodiment, the separator structure 205 can include an oxide-based electrolyte. An exemplary oxide-based electrolyte comprises lanthanum lithium titanate (Li _0.34 La _0.56 TiO ₃ ) Al-doped lanthanum lithium zirconate (Li) _6.24 La ₃ Zr ₂ Al _0.24 O _11.98 ) Ta-doped lanthanum lithium zirconate (Li) _6.4 La ₃ Zr _1.4 Ta _0.6 O ₁₂ ) And lithium aluminum titanium phosphate (Li) _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ )。

In another embodiment, the separator structure 205 can include a solid electrolyte. Exemplary solid electrolytes include sulfide-based electrolytes, such as lithium tin phosphorus sulfide (Li ₁₀ SnP ₂ S ₁₂ ) Lithium phosphorus sulfide (beta-Li) ₃ PS ₄ ) And lithium phosphorus sulfur chloride iodide (Li) ₆ PS ₅ Cl _0.9 I _0.1 )。

In some embodiments, the diaphragm structure 205 may include a solid lithium ion conducting ceramic, such as a lithium-filled garnet.

In one embodiment, the separator structure 205 comprises a microporous separator material comprising a particulate material and a binder, and the microporous separator material has a porosity (void fraction) of at least about 20 volume percent. The pores of the microporous separator material will have a diameter of at least And will generally fall within about->To->Within a range of (2). The porosity of the microporous separator material is typically less than about 75%. In one embodiment, the microporous separator material has a porosity (void fraction) of at least about 25 volume percent. In one embodiment, the microporous separator material has a porosity of about 35% to 55%.

The binder for the microporous separator material may be selected from a wide range of inorganic materials or polymeric materials. For example, in one embodiment, the binder is an organic material selected from the group consisting of: silicates, phosphates, aluminates, aluminosilicates and hydroxides, such as magnesium hydroxide, calcium hydroxide, and the like. For example, in one embodiment, the binder is a fluoropolymer derived from monomers containing vinylidene fluoride, hexafluoropropylene, tetrafluoropropene, and the like. In another embodiment, the binder is a polyolefin, such as polyethylene, polypropylene, or polybutylene, having any of a range of different molecular weights and densities. In another embodiment, the binder is selected from the group consisting of: ethylene-diene-propylene terpolymers, polystyrene, polymethyl methacrylate, polyethylene glycol, polyvinyl acetate, polyvinyl butyral, polyacetal and polyethylene glycol diacrylate. In another embodiment, the binder is selected from the group consisting of: methylcellulose, carboxymethylcellulose, styrene rubber, butadiene rubber, styrene-butadiene rubber, isoprene rubber, polyacrylamide, polyvinyl ether, polyacrylic acid, polymethacrylic acid and polyethylene oxide. In another embodiment, the binder is selected from the group consisting of: acrylates, styrenes, epoxies, and silicones. In another embodiment, the binder is a copolymer or blend of two or more of the above polymers.

The particulate material comprised by the microporous separator material may also be selected from a wide range of materials. In general, such materials have relatively low electron and ion conductivities at operating temperatures and do not corrode at the operating voltages of the battery electrodes or current collectors that contact the microporous separator material. For example, in one embodiment, the particulate material has a carrier ion (e.g., lithium) conductivity of less than 1×10 ^-4 S/cm. Further by way of example, in one embodiment, the particulate material has a carrier ionic conductivity of less than 1 x 10 ^-5 S/cm. Further by way of example, in one embodiment, the particulate material has a carrier ionic conductivity of less than 1 x 10 ^-6 S/cm. Exemplary particulate materials include particulate polyethylene, polypropylene, tiO ₂ -a polymer composite, silica aerogel, fumed silica, silica gel, silica hydrogel, silica xerogel, silica sol, colloidal silica, alumina, titania, magnesia, kaolin, talc, diatomaceous earth, calcium silicate, aluminum silicate, calcium carbonate, magnesium carbonate or a combination thereof. For example, in one embodiment, the particulate material comprises a particulate oxide or nitride, such as TiO ₂ 、SiO ₂ 、Al ₂ O ₃ 、GeO ₂ 、B ₂ O ₃ 、Bi ₂ O ₃ 、BaO、ZnO、ZrO ₂ 、BN、Si ₃ N ₄ And Ge3N4. See, e.g., p.arora and j.zhang, "battery separator (Battery Separators)", chemical Reviews (Chemical Reviews) 2004,104,4419-4462. In one embodiment, the average particle size of the particulate material will be about 20nm to 2 microns, more typically 200nm to 1.5 microns. In one embodiment, the particulate material has an average particle size of about 500nm to 1 micron.

In alternative embodiments, the particulate material comprised by the microporous separator material may be bonded by techniques such as sintering, bonding, curing, etc., while maintaining the desired void fraction for electrolyte ingress to provide ionic conductivity for operation of the battery.

In the assembled battery, the microporous separator material of the separator structure 205 is suitable for use as a nonaqueous electrolyte permeation for a secondary battery electrolyte. Generally, the nonaqueous electrolyte includes lithium salts and/or mixtures of salts dissolved in an organic solvent and/or solvent mixture. Exemplary lithium salts include inorganic lithium salts, such as LiClO ₄ 、LiBF ₄ 、LiPF ₆ 、LiAsF ₆ LiCl and LiBr; and organolithium salts, such as LiB (C) ₆ H ₅ ) ₄ 、LiN(SO ₂ CF ₃ ) ₂ 、LiN(SO ₂ CF ₃ ) ₃ 、LiNSO ₂ CF ₃ 、LiNSO ₂ CF ₅ 、LiNSO ₂ C ₄ F ₉ 、LiNSO ₂ C ₅ F ₁₁ 、LiNSO ₂ C ₆ F ₁₃ And LiNSO ₂ C ₇ F ₁₅ . Exemplary organic solvents that dissolve the lithium salt include cyclic esters, chain esters, cyclic ethers, and chain ethers. Specific examples of the cyclic esters include propylene carbonate, butylene carbonate, γ -butyrolactone, vinylene carbonate, 2-methyl- γ -butyrolactone, acetyl- γ -butyrolactone, and γ -valerolactone. Specific examples of the chain esters include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropyl carbonate, methylethyl carbonate, methylbutyl carbonate, methylpropyl carbonate, ethylbutyl carbonate, ethylpropyl carbonate, butylpropyl carbonate, alkyl propionate, dialkyl malonate, and alkyl acetate. Specific examples of cyclic ethers include tetrahydrofuran, alkanes Tetrahydrofuran, dialkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1, 3-dioxolane, alkyl-1, 3-dioxolane and 1, 4-dioxolane. Specific examples of the chain ether include 1, 2-dimethoxyethane, 1, 2-diethoxyethane, diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether and tetraethylene glycol dialkyl ether.

In one embodiment, the microporous separator membrane of the separator membrane structure may be infiltrated with a nonaqueous organic electrolyte comprising a mixture of a lithium salt and a high purity organic solvent. In addition, the electrolyte may be a polymer using a polymer electrolyte or a solid electrolyte.

When the electrode structure 202 is of the cathode type, the electrode buss 208 is a cathode electrode buss and when the electrode structure 202 is of the anode type, the electrode buss is an anode electrode buss. Similarly, when the counter electrode structure 204 is of the cathode type, the counter electrode busbar is a cathode electrode busbar, and when the counter electrode structure 204 is of the anode type, the counter electrode busbar is an anode electrode busbar. In an example embodiment, the anode type bus bar is a copper bus bar and the cathode type bus bar is an aluminum bus bar. In other embodiments, electrode buss 208 and counter electrode buss 210 can be any suitable conductive material to allow electrode assembly 200 to function as described herein.

The counter electrode structure 204, and more specifically the counter electrode current collector 218, is directly connected to the counter electrode bus bar 210. That is, the counter electrode current collector 218 is welded, brazed or glued to the counter electrode bus bar 210 without any components being electrically or physically positioned between the counter electrode current collector and the counter electrode bus bar. The welding may be performed using a laser welder, friction welding, ultrasonic welding, or any suitable welding method for welding the counter electrode buss 210 to the counter electrode current collector 218.

Fig. 3A and 3B illustrate an example technique for connection between one of the counter electrode collectors 218 and the counter electrode bus bar 210. Fig. 3A is a view of an end portion of one of the counter electrode collectors 218. The end of the counter electrode current collector 218 contains a slot 300 sized and shaped to receive the counter electrode buss 210. A portion 302 of the counter electrode current collector 218 extends beyond the slot 300. The counter electrode buss 210 is inserted through the slot 300 and a portion 302 of the counter electrode current collector 218 is bent to contact the counter electrode buss 210 as shown in fig. 3B. Then, the portion 302 of the counter electrode collector 218 that is in contact with the counter electrode bus bar 210 is welded to the counter electrode bus bar 210.

Fig. 17 illustrates another example technique for connection between one of the counter electrode collectors 218 and the counter electrode bus bar 210. In this example, the counter electrode current collector 218 does not include the slot 300. The portion 1700 of the counter electrode current collector 218 is bent at a substantially ninety degree angle and the counter electrode buss 210 is positioned above the portion 1700. The counter electrode buss 210 is then directly attached to the portion 1700 of the counter electrode current collector 218, such as by gluing, welding, brazing, or using any other suitable technique for joining the counter electrode current collector 218 to the counter electrode buss 210.

Returning to fig. 2, each member of the current limiter population 206 is electrically connected between a different electrode current collector 214 and the electrode buss 208. The current limiter 206 is configured to limit the current that may flow through the electrode current collector 214 and, correspondingly, through the electrode structure 202 to which it is connected. Thus, for example, if a short circuit is formed between one of the electrode collectors 214 and one of the counter electrode collectors 218, the current limiter 206 limits the amount of current that can flow from the other electrodes and counter electrodes of the electrode assembly and thereby limits the temperature experienced by the electrode assembly 200 and prevents thermal runaway. Specifically, the current limiter 206 limits the amount of current that can be conducted through the unit cell during discharge of the electrode assembly in which there is an electrical short between the electrode of the unit cell and the counter electrode to a value I that is less than the current that would induce thermal runaway of members of the unit cell group through the members of the unit cell group (sometimes referred to herein as I _tr Or I _L ). The current limiter provides a soft landing for the battery in case of a short circuit. The current limiter continuously allows in case of a short circuitMany non-zero levels of current flow, but limiting the current to a level below which thermal runaway will be triggered. This current will continue to flow until the battery is discharged and the risk of thermal runaway ends.

The current limiter 206 is a resistive current limiter. The current limiter 206 has a non-zero resistance within the normal operating temperature range of the electrode assembly 200. In one example, the normal operating temperature is between minus 20 ℃ and 80 ℃. In other embodiments, the normal operating temperature is between minus 40 ℃ and 85 ℃, between minus 40 ℃ and 150 ℃, or any other suitable normal operating temperature range. The resistance causes the current limiter 206 to limit the current that may pass through any unit cell and prevent the current from reaching a level that may cause catastrophic failure or any other maximum current level that is determined for other performance or abuse tolerance reasons determined during battery design. The current limiter 206 does not rely on any PTC characteristics of the fuse or resistive material. That is, although the current limiter 206 may exhibit PTC, the current limiter 206 does not require PTC to function as described herein. Conversely, the resistance of the current limiter 206 in the normal operating temperature range of the electrode assembly 200 is sufficient to limit the current. In some embodiments, the resistance may increase or decrease over a normal operating temperature range (i.e., the current limiter may have a negative temperature coefficient). The current limiters 206 are each electrically in series with the electrode current collector 214 to which they are attached. Thus, the resistance of each current limiter 206 and its associated electrode structure 202 is increased by increasing the resistance of the associated electrode structure 202 and the resistance of the current limiter 206 attached thereto. Conventionally, it is discouraged to add resistance to the battery, as the added resistance will increase the losses experienced by the battery as current flows into the electrode structure 202 (during charging) and out of the electrode structure (during discharging). However, because the electrode current collectors 214 are all connected in parallel (electrically parallel) to the electrode bus 208, the increase in total resistance seen at the electrode bus 208 is much less than the resistance of each individual current limiter 206. Further, the resistance of the current limiter 206 in the present disclosure is selected to be small enough to have a limited voltage drop across the current limiter 206 and thus a limited power loss. In an example embodiment, the resistance of the current limiters is selected to have a voltage drop of no more than 20mV across each of the current limiters 206 during charging or discharging at 1C rates to limit losses during normal operation while still protecting the battery during a short circuit.

In the example embodiment, without the current limiter 206, each individual unit cell (i.e., each pair of one electrode structure 202 and one counter electrode structure 204) has a relatively small size (compared to a layered battery), a relatively low capacity, and sufficiently high internal resistance that the current through the isolated unit cell cannot reach a level sufficient to cause thermal runaway and catastrophic failure even when there is a short circuit between the unit cell's electrode structure 202 and the counter electrode structure 204. However, when a plurality of unit battery cells are connected in parallel to a bus bar (e.g., bus bar 208) in an electrode assembly (e.g., electrode assembly 200), all of the unit battery cells contribute current to the unit battery cells having a short circuit therein. In this case, without the current limiter 206, sufficient current may pass through the shorted unit cell to cause thermal runaway and catastrophic failure of the electrode assembly 200 and the battery containing the same. By adding the current limiter 206, the resistance of the unit cell is effectively increased. According to Ohm's law, increasing the resistance will result in a corresponding decrease in maximum current at a fixed voltage V of the unit cell.

More specifically, the capacity of the electrode assembly 200 is subdivided into a plurality (n) of electrode unit cells, each of which includes one electrode structure 202 and one counter electrode structure 204. Each unit cell forms a voltage (V). Each individual electrode unit cell has its own characteristic resistance (R _bl ) Which is a function of the conductivity and geometry of the unit cell assembly. Each individual unit cell is capable of crossing a short circuit (e.g., forced Internal Short Circuit (FISC)) resistance (R _s ) Releasing powerFor an individual unit cell, the FISC power is given by:

when the electrode structure 202 and counter electrode structure 204 of each unit cell are connected in parallel to their respective bus bars 208, 210, all unit cells contribute to the FISC across the individual affected (i.e., shorted) unit cellsAnd performing power discharge. The FISC power of all the unit cells among the parallel-connected battery cells is given by:

current limiters 206 are added (each of the current limiters has a non-zero resistance (R _cl* ) A) generates a FISC power of the short-circuited unit cell given by:

Resistor R of each current limiter 206 _cl* FISC power selected so as to short the unit cellsLess than thermal runaway->Or other maximum power considerations selected due to battery design constraints.

The desired resistance of the current limiter 206 may also be viewed from the perspective of limiting the current through the shorted unit cell to a resistance below a threshold current sufficient to cause thermal runaway. Therefore, by knowing the voltage generated by each unit cell, the capacity of each unit cell, the internal resistance of each unit cell, the resistance of the electrode bus 208, and the resistance of the counter electrode bus 210, the resistance of the current limiter 206 that limits the current through the shorted unit cell to less than the threshold current required to cause thermal runaway can be calculated. The threshold current required to cause thermal runaway may vary somewhat depending on the configuration of the electrode assembly and the capacity of the individual unit cells, but will remain relatively constant for similarly configured electrode assemblies. In an example embodiment, the threshold current is about 8 amps. In other embodiments, the threshold current may be about 4 amps, about 8 amps, about 10 amps, about 12 amps, or between 8 amps and 12 amps. The resistance required for the current limiter 206 will vary depending on the particular configuration of the battery and its components. For similar electrode assemblies, the resistance required to limit the current below the threshold current will generally increase as the capacity of the individual unit cell increases.

More specifically, the capacity of a conventional stacked battery cell is subdivided into a plurality of electrode unit battery cells (N), wherein each of the positive and negative electrodes forms a voltage (V). The number of unit cells in the complete stack is denoted by the capital letter N, and the number of unit cells as variables (e.g., when iteratively measured with a different number of unit cells) is denoted by the small letter N. Each individual electrode unit cell has its own characteristic resistance (R _bl ) Which is a function of the conductivity and geometry of the unit cell assembly. Each individual unit cell is capable of crossing a Forced Internal Short Circuit (FISC) resistor (R _s ) Discharging current (I) _bl ). The FISC current of an individual unit cell is given by:

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when the positive and negative electrodes of each unit cell pass through a battery having its own characteristic resistance (R _t ) When their respective collector terminals are connected in parallel, all of the battery cells generate a current (I) that is discharged across the FISCs of the individual affected battery cells _{Battery cell} ). The FISC current of all the unit cells among the parallel-connected battery cells is given by:

in at least some cases, the characteristic resistance of the individual unit cells is low enough that it is capable of discharging a current across the FISC sufficient to exceed the thermal runaway current (I _tr ) The thermal runaway current is a current that may be sufficient to cause self-accelerating exothermic decomposition and thermal runaway. When multiple electrode unit cells are connected to each other through a shared terminal, it is increasingly likely that the discharge current of the FISC across the individual affected unit cells exceeds the thermal runaway current (I _t5 ) And causes catastrophic failure of the battery cells.

The resistance of each current limiter 206 is selected to be sufficient to limit the current that can pass through any individual unit cell to a thermal runaway current (I _tr ) The following is given. The resistance (R _cl* ) Is determined to satisfy the following resistances:

wherein V is _TOC Is the voltage of the unit cell at maximum charge, and R _S,WCFISC The unit cell in the assembly corresponding to the no current limiting device forces the resistance of the assembly of N unit cells to an internal short circuit at maximum charge in the worst case. In an example, the worst case is considered to occur when the resistance of the forced internal short circuit is approximately equal to the resistance of the shorted unit cell. Impedance is used because of electrorheological properties in the event of a short circuitThe melting is very rapid. In one embodiment, R _S,WCFISC Is an impedance of 20 kHz. Thus, the resistance R _S,WCFISC Can be described by the following:

R _s,:CFISC ＝R _20kAB (V _TOC ,N) (7)

Other embodiments may use impedance or dc resistance at any other frequency. In some embodiments, the actual shorting resistance of the shorted cell is calculated and used in equation (6), rather than the worst case internal shorting resistance R _s,WCFISC . As used herein, unless otherwise indicated, the shorting resistor R _s May refer to the actual measured short circuit resistance or worst case internal short circuit resistance R of the unit cell _s,WCFISC . An example method for determining the actual short circuit resistance is provided below.

The resistance of the individual unit cells is determined by the resistance at maximum charge, taking further into account the number of unit cell subdivisions and the resistance of the terminals calculated based on their material composition and geometry. For the example using a 20kHz impedance, the resistance of a unit cell is given by:

in an example embodiment, the thermal runaway current (I) used in equation (6) above is determined by performing a worst case forced internal short circuit determination described below _tr ). In other embodiments, the thermal runaway current (I _tr ) May be estimated, derived from a simulation, determined using different assays, or obtained by any other suitable method. However, it was determined that the thermal runaway current (I) was then used in equation (6) _tr ) To determine the resistance (R _cld ). By selectively providing a resistor R _cld The current limiter 206 will effectively limit the current through any unit cell to less than the thermal runaway current (I _tr ) Even if an internal short circuit occurs in a unit cellIn this case.

For the exemplary embodiment, each current limiter 206 has a resistance of about 0.25 ohms (Ω) at 25 degrees celsius (°c) and limits the short circuit current to less than about 8 amps. This produces a voltage drop of 20mV or less across each current limiter 206 when the electrode assembly 200 is charged or discharged at a 1C rate. In other embodiments, the resistance of each current limiter 206 is between 0.25Ω and 2.5Ω. In some embodiments, the resistance of each current limiter 206 is between 0.1 Ω and 1.5 Ω. These ranges provide a series of resistances that balance the need to limit current during a short circuit while also limiting losses during normal operation of the battery. The exact values within the range, as well as the range to be selected, may be selected based on the voltage, capacity, or other characteristics of the particular battery. More generally, in some embodiments, the resistance of each current limiter 206 is determined by selecting a resistance that produces a voltage drop of less than 0.5 volts when the electrode assembly 200 (or individual unit cell) is charged or discharged at a 1C rate when discharged from a maximum charge (TOC) condition. That is, the current at 1C times the resistance of the current limiter 206 is less than 0.5 volts to minimize losses during normal operation while still adequately limiting the current during a short circuit.

In an example embodiment, the current limiter 206 is positioned on the electrode buss 208. The current limiter is physically positioned between the electrode current collector 214 and the electrode buss 208. In other embodiments, the current limiter 206 may be electrically connected between the electrode current collector 214 and the electrode buss 208, but physically located outside the connection between the electrode current collector 214 and the electrode buss 208.

Referring now to fig. 4A and 4B, the example current limiter 206 includes a single layer 400 of conductive adhesive disposed on a surface 402 of the electrode buss 208 to which the electrode current collector 214 is to be welded. The electrode current collector 214 includes a slot 404 (fig. 4B) and a portion 406, similar to the slot 300 and portion 302 of the counter electrode current collector 218 shown in fig. 3A and 3B, which are similarly used to connect the electrode current collector 214 to the electrode buss 108. Each individual current limiter 206 is a portion 408 of the single layer 400 located between portions 406 of the current collector bent over and welded to the electrode buss 208. In other embodiments, the conductive adhesive is applied to the electrode buss 208 in separate portions, one for each electrode current collector 214 to be connected to the electrode buss 208. For example, a conductive adhesive is applied to electrode buss 208 around the location of portion 406 over which the electrode current collector will be positioned when portion 406 is bent over the electrode buss. Each application of the conductive adhesive and thus each current limiter 206 is physically separate from each other application of the conductive adhesive. In other embodiments, the conductive adhesive of the current limiter 206 is applied to each electrode current collector 214; such that the conductive adhesive will be positioned around the location of portion 406 in fig. 4B and each current limiter 206 will be physically separated from the other current limiters 206. In other embodiments, the bus bars are connected to the current collector by any other suitable connection arrangement (e.g., without the use of slots, with the bus bars on top of the current collector ends, etc.), with a conductive adhesive positioned between the current collector and the bus bars.

Fig. 18 illustrates another example embodiment in which the electrode current collector 214 does not include a slot 300. The current limiter 206 comprises a single layer 1801 of conductive adhesive disposed on the bottom surface 1800 of the electrode buss 208 to which the electrode current collector 214 is to be attached. A portion 1802 of the electrode current collector 214 is bent at a substantially ninety degree angle and the electrode buss 208 is positioned above the portion 1802. It should be appreciated that the portion 1802 need not be bent to exactly ninety degrees and may be generally perpendicular to the remainder of the current collector. Electrode buss 208 is then attached to the portion 1802 of electrode current collector 214, such as by gluing, welding, brazing, or using any other suitable technique for joining electrode current collector 214 to electrode buss 208. In an example embodiment, electrode buss 208 is attached to section 1802 by: the electrode buss is hot pressed to soften the conductive adhesive and pressure is applied to the buss to adhere the electrode buss 208 to the section 1802 using the conductive adhesive. Although shown as interfacing with a conductive adhesive, it should be understood that the portion 1802 of the current collector may extend into the conductive adhesive. Each individual current limiter 206 is a portion 1804 of the single layer 1801 located between portions 1802 of the current collector bent over and attached to the electrode buss 208. In other embodiments, as shown, for example, in fig. 19, the conductive adhesive is applied to the electrode buss 208 in separate portions 1900, one for each electrode current collector 214 to be connected to the electrode buss 208. For example, conductive adhesive is applied to electrode buss 208 around the location of section 1802, and when section 1802 is bent over the electrode buss, the electrode current collector will be positioned over the section. Each application of the conductive adhesive and thus each current limiter 206 is physically separate from each other application of the conductive adhesive. In other embodiments, the conductive adhesive of the current limiter 206 is applied to each electrode current collector 214; such that the conductive adhesive will be positioned around the location of the section 1802 and each current limiter 206 will be physically separated from the other current limiters 206.

In still other embodiments, resistors other than conductive adhesive are used for the current limiter 206. For example, a conductive film having a desired resistance may be applied to the electrode buss 208 in the form of an integral strip, applied to the electrode buss in separate portions, or applied to each electrode current collector 214 in separate portions in a manner similar to a conductive adhesive. Alternatively, a non-tacky conductive polymer may be applied in place of the conductive adhesive. Additionally, in some embodiments, discrete resistors may be electrically connected between the electrode current collectors 214 and the electrode buss 208. The discrete resistor may be physically located between electrode current collector 214 and electrode bus 208, or may be physically located outside the interface between electrode current collector 214 and electrode bus 208, but electrically located between electrode current collector 214 and electrode bus 208. The discrete resistors may be any suitable resistors including wire wound resistors, thick film resistors, thin film resistors, carbon stack resistors, metal film resistors, foil resistors, and the like.

In some embodiments, one or more interface layers are included between the current limiter 206 and the electrode buss 208 or between the current limiter 206 and the electrode current collector 214. In general, the resistance between electrode buss 208 and each electrode current collector 214 is defined by the resistance of current limiter 206 plus the resistance of the interface between current limiter 206 and electrode current collector 214 plus the resistance of the interface between current limiter 206 and electrode buss 208. In general, interface resistance may result from imperfect (e.g., a "true" connection rather than an "ideal") electrical connection between current limiter 206 and electrode buss 208 and electrode current collector 214. Without being bound by any particular theory, imperfect electrical connection may be caused by microscopic structural changes, for example, of the surfaces of electrode buss 208 and/or electrode current collector 214, the distribution and structure of conductive particles in current limiter 206, and the like. The interface layer is provided to improve the electrical connection between these components, thereby reducing the series resistance of the electrical connection between the current limiter 206, the electrode buss 208, and the electrode current collector 214. Referring now to fig. 14-16, an embodiment similar to that shown in fig. 4B is shown. Like reference numerals in fig. 14-16 refer to like components in fig. 4B. In fig. 14, an interface layer 1400 is applied to the electrode buss 208. In fig. 15, an interface layer 1500 is applied to the electrode current collector 214. The interface layer 1500 may be applied to each current collector 214 or to less than all of the current collectors 214. In fig. 16, an interface layer 1400 is applied to electrode buss 208 and an interface layer 1500 is applied to electrode current collector 214.

In some embodiments, interface layers 1400 and 1500 are carbon-based coatings. For example, interface layers 1400 and/or 1500 may be coatings produced by coating carbon nanotube paste onto electrode buss 208 and/or electrode current collector 214. In other embodiments, the interfacial layer is a graphite coating or any other suitable conductive coating. In some embodiments, interface layers 1400 and/or 1500 are applied using a thermal anvil method in which heat is applied to electrode buss 208 and/or electrode current collector 214 to coat electrode buss 208 and/or electrode current collector 214 with a selected material to form interface layers 1400 and/or 1500.

The conductive adhesive used in the current limiter 206 in the exemplary embodiment is an adhesive polymer, copolymer, or blend having a conductive material suspended therein. In an example embodiment, the conductive adhesive is a thermoplastic material. In other embodiments, the conductive adhesive is a thermoset material. The adhesive polymer is substantially non-conductive (e.g., insulating) prior to suspending the conductive material in the adhesive polymer. In general, the desired polymers are (a) stable in the environment of the Li-ion battery cell (i.e., not dissolved in the electrolyte, not reacted with electrolyte components or any other battery components, or not subjected to redox chemistry or reactions that degrade materials during battery cell operation) and (b) any polymer that has a melting point above the typical operating temperature of a Li-ion battery. Since adhesion is an important property of the conductive adhesive, a polymer exhibiting adhesive quality is desirable as at least one component of the conductive adhesive. Flexibility in the polymer is another desirable property. Thus, a material or blend of materials having some elasticity and in particular having a glass transition temperature (Tg) above 0 ℃ is preferred but not required. In some embodiments, the conductive adhesive is a polymer blend with at least one component having high elasticity (as measured by standard methods such as modulus and/or elongation at break). In some embodiments, the adhesive polymer is a flowable adhesive polymer. In such embodiments, the conductive adhesive should have flow properties that allow for melt processing, including compounding of conductive aids and other additives (if desired), film/sheet preparation by standard methods such as cast film, blown film, and calendaring. For example, the melt flow index (I2, 190 ℃ C., ASTM D1238) of the polymer blend for the conductive adhesive should be in the range of 0.1 grams (g)/10 minutes (min) to 1000g/10min, preferably 0.1g/10min to 100g/10min, most preferably 0.5g/10min to 20g/10 min. The melting point of the polymer used in the conductive adhesive should allow for melt processing and bonding to the battery cell by melt pressing or related techniques, and should be higher than the typical operating temperature range of the battery cell. Polymers melted from 40 ℃ to 300 ℃ may be used for the conductive adhesive. Polymers having a melting point in the range of 60 ℃ to 200 ℃ are preferred, and polymers having a melting point in the range of 70 ℃ to 165 ℃ are most preferred.

Exemplary adhesive polymers or copolymers suitable for use in the conductive adhesive include EAA (ethylene-co-acrylic acid) and EMAA (ethylene-co-methacrylic acid), ionomers of EAA or EMAA, polyethylene and copolymers thereof (e.g., ethylene/1-octene, ethylene/1-hexene, ethylene/1-butene, and ethylene/propylene copolymers), polypropylene and copolymers thereof, functionalized or derivatized polyethylene or polypropylene (e.g., maleic anhydride grafted materials), and the like.

The conductive material suspended in the polymer to form the conductive adhesive may be any powder, fiber, particle, etc. that imparts the desired conductivity to the conductive adhesive after compounding with the polymer blend. Materials that impart the desired conductivity at lower loadings are most desirable because high loadings of additives may alter the properties of the polymer blend in an undesirable manner. For example, high loadings may result in significantly reduced melt processability, affecting the ability to manufacture films or sheets of conductive polymers using conventional equipment. In addition, conductive additives are often expensive materials, and lower loadings are desired to keep manufacturing costs down.

The conductive material may be metal powder or fibers, conductive carbon black, metal coated carbon fibers and carbon nanotubes or blends thereof. In various embodiments, the conductive material may be carbon black, nickel particles, copper particles, gold particles, silver particles, tin particles, titanium particles, graphite particles, molybdenum particles, platinum particles, chromium particles, aluminum particles, or any other metal particles, including alloys. Preferred conductive materials for the conductive adhesive are metal coated carbon fibers and conductive carbon black or mixtures thereof. The metal coated carbon fibers may be coated with nickel, copper, gold, silver, tin, titanium, molybdenum, platinum, chromium, aluminum, or any other metal coating, including alloys. In the most preferred examples, the conductive material comprises nickel-coated carbon fibers and "superconducting" carbon black (examples include, but are not limited to Nouryon Ketjenblack EC-J and EC 600-JD materials, orion Printex XE2B, cabot Vulcan XCmax ^TM 22)。

For embodiments where the conductive material is a fiber (e.g., nickel coated carbon fiber), the conductive material will generally have an elongated shape. In such embodiments, it is preferred that the fibers have a relatively large aspect ratio (length: diameter). In one example embodiment, the aspect ratio of the nickel coated carbon fiber used as the conductive material in the conductive adhesive is about 850:1. Other useful aspect ratios of the conductive material are 10:1 to 10,000:1, preferably 50:1 to 5000:1, and most preferably 100:1 to 2000:1.

The loading of the conductive material into the polymer to form the conductive adhesive may be in the range of 1% to 50% conductive material (by weight of the total mixture). Preferably, the loading of the conductive material is 2% to 40%, and most preferably the loading is 3% to 30%.

The resistivity of the conductive adhesive should be 5.0x10 ^-7 Omega-cm and 5.0x10 ³ Omega-cm, preferably 5.0x10 ^-5 Omega-cm and 5.0x10 ¹ Omega-cm and most preferably 5.0x10 ^-3 Omega-cm and 5.0x10 ^-1 In the range of omega-cm. The polymer resistivity is measured by: a sheet or film of the polymer blend is made with a conductive additive and then laminated to a copper test structure consisting of four rectangular bars adhered adjacent to one another in an array at defined intervals. Lamination may be accomplished using methods such as hot pressing or heated calendaring. Once lamination is completed, resistivity measurements are achieved using a typical four-point probe method, in which the source probe applies current through the film sheet by contacting the two outermost rods, and the sense probe measures the potential between the innermost rods, allowing the bulk resistivity to be determined when defining the geometry of the four-point test structure array and the thickness of the sheet or film.

In an example embodiment, the conductive material is carbon black. The conductive adhesive is formed by mixing carbon black into the adhesive polymer until the volume resistivity of the adhesive polymer is between about 0.01 Ω -cm and 1.0 Ω -cm. The resistivity can be adjusted by adjusting the amount of carbon black added to the binder polymer. Adding more carbon black will decrease the resistivity (i.e., make it more conductive) and adding less carbon black will increase the resistivity (i.e., make it less conductive). In an example embodiment, carbon black is added to the binder polymer in an amount between 5 wt% and 30 wt% to achieve the desired resistivity. The conductive adhesive thus prepared is applied to the electrode buss 208 at a thickness between 20 microns and 200 microns thick. By adjusting the resistivity and applied thickness of the adhesive polymer, a desired resistance of the current limiter 206 may be achieved.

Fig. 5 is a simplified diagram of another example electrode assembly 500 in a battery for cycling between a charged state and a discharged state. Electrode assembly 500 is similar to electrode assembly 200 and like reference numerals are used to identify common components. For clarity of illustration, the separator structure 205 is not shown in fig. 5, but is included in this example electrode assembly 500. Unlike electrode assembly 200, electrode assembly 500 includes an additional current limiter cluster 502. Additional current limiters 502 are each electrically connected between a different one of the counter electrode current collectors 218 and the counter electrode bus bar 210. In some embodiments, the additional current limiter 502 is the same as the current limiter 206 discussed above and is connected in the same manner as the current limiter 206. However, in some embodiments, the additional current limiter 502 has a different composition and/or is different from the current limiter 206. For example, a conductive film may be used as the resistance of the additional current limiter 502, while a conductive adhesive is used in the current limiter 206. Alternatively, one type of conductive adhesive may be used in the current limiter 206 and a different type of conductive adhesive may be used in the additional current limiter 502. This may be particularly useful when counter electrode buss 210 and electrode buss 208 are made of different materials that may be adhered to different conductive adhesives in different ways. As another example, the additional current limiter 502 may use a different conductive material suspended in a conductive adhesive than the current limiter 206. Additionally, in some embodiments, the additional current limiter 502 has a different resistance than the current limiter 206. In certain embodiments, when the resistance of current limiter 206 is sufficient to limit the current below a threshold that would result in a catastrophic failure, the resistance of additional current limiter 502 is less than the resistance of current limiter 206, including a resistance of less than 0.25 Ω.

Fig. 6 is a simplified diagram of another example electrode assembly 600 in a battery for cycling between a charged state and a discharged state. Electrode assembly 600 is similar to electrode assembly 200 and like reference numerals are used to identify common components. For clarity of illustration, some details of the electrode structure 202 and the counter electrode structure 204 are removed, but all aspects of the electrode structure 202 and the counter electrode structure 204 discussed above are the same in the electrode assembly 600. Unlike electrode assembly 200, electrode assembly 600 includes an additional electrode structure population 602 directly connected to electrode buss 208. That is, the additional electrode structure 602 is connected to the electrode buss 208 without the current limiter 206.

Fig. 7 is a simplified diagram of another example electrode assembly 700 in a battery for cycling between a charged state and a discharged state. Electrode assembly 700 is similar to electrode assembly 500 and like reference numerals are used to identify common components. For clarity of illustration, some details of the electrode structure 202 and the counter electrode structure 204 are removed, but all aspects of the electrode structure 202 and the counter electrode structure 204 discussed above are the same in the electrode assembly 700. Unlike electrode assembly 500, electrode assembly 500 includes a further group of electrode structures 602 and a further group of counter electrode structures 704 all connected directly to electrode buss 208. That is, the further electrode structure 602 and the further counter electrode structure 704 are connected to the electrode buss 208 without the current limiter 206 or the further current limiter 502.

Fig. 9 is an example stacked battery cell 900 produced as part of the manufacture of a secondary battery. To form a secondary battery, an electrode assembly, such as the electrode assembly 200, 500, 600, or 700, is first assembled. The electrode structure 202, the counter electrode structure 204 and, if applicable, the further electrode structure 602 and/or the further counter electrode structure 704 are assembled. The formed electrode structure 202, counter electrode structure 204, further electrode structure 602 and further counter electrode structure 704 will be referred to as "electrode sub-unit" in the following paragraphs. A predetermined number of electrode subunits are stacked with the separator 205 in a stacking direction (e.g., in a width direction in fig. 2) to form a multi-cell electrode stack. Typically, at least ten electrode structures 202 and at least ten counter electrode structures 204 are included in the multi-cell electrode stack. In some embodiments, at least twenty electrode structures 202 and at least twenty counter electrode structures 204 are included in a multi-cell electrode stack. Other embodiments may include any suitable number of electrode structures 202 and at least ten counter electrode structures 204 in a multi-cell electrode stack. The multi-cell electrode stack is then placed in a compression constraint with a pressure plate that applies pressure to the multi-cell electrode stack to adhere all of the electrode subunits together.

In the multi-cell electrode stack, the electrode structure and the counter electrode structure extend in a longitudinal direction (e.g., in the length direction in fig. 2) perpendicular to the stacking direction. The end portions of the electrode current collector (e.g., the portions of the electrode current collector 214 extending over the remainder of the electrode structure 202 in fig. 4B, 14, 15, 16, 18, and 19) extend beyond the electrode active material and separator structure in the longitudinal direction. The end portions extending over the electroactive material and the separator structure are bent to extend substantially perpendicular to the longitudinal direction of the electrode structure and in the stacking direction or in a direction opposite to the stacking direction, as shown in fig. 4B, 14, 15, 16, 18, and 19. In the embodiment without the slot (e.g., fig. 18 and 19), the end portion is bent before the electrode buss is positioned to extend in the stacking direction, with the surface of the electrode buss being in contact with the end portion of the electrode current collector (i.e., the bent end portion). In an exemplary embodiment, a conductive adhesive layer (e.g., a conductive adhesive as discussed herein and acting as a current limiting device) is located between the surface of the electrode buss and the end portion of the electrode current collector. In some embodiments, a conductive adhesive layer is disposed on a surface of the electrode buss that contacts the electrode current collector. In other embodiments, a conductive adhesive layer is disposed on the electrode current collector. In still other embodiments, the conductive adhesive layer is a separate layer positioned between the electrode buss and the electrode current collector. Heat and pressure are applied to the electrode bus bars to adhere end portions of the electrode current collectors to the bus bars through the conductive adhesive layer. The heat applied may be from 100 ℃ to 300 ℃, preferably from 125 ℃ to 250 ℃ and most preferably from 150 ℃ to 225 ℃. The pressure may be 10psi to 1000psi, preferably 15psi to 750psi and more preferably 20psi to 500psi.

In embodiments that use slots in the current collector (e.g., fig. 4B and 14-16), the bus bars are inserted through the slots before the current collector bends. In such embodiments, the electrode buss 208 and counter electrode buss 210 are placed through slots 404, 300 (shown in fig. 3A-4B) of the respective current collectors 214, 218 with the current limiter 206 (and 502 if applicable) located between the buss 208, 210 and the current collectors 214, 218. Once the bus bars 208, 210 are placed through the slots 404, 300, the portions 406, 302 are folded down toward their respective bus bars 208, 210, respectively. Electrode buss 208 is welded to portion 406 of electrode collector 214 and counter electrode buss 210 is welded to portion 302 of counter electrode collector 218. The welding may be performed using a laser welder, friction welding, ultrasonic welding, or any suitable welding method for welding the bus bars 208, 210 to the current collectors 214, 218. After welding the bus bars to the multi-cell electrode stack, the stacked battery cells 900 are completed and may be placed in a pouch, metal can, or other suitable container formed by the cells. In other embodiments, any other suitable method of connecting electrode buss 208 and counter electrode buss 210 to the current collector may be used, including methods without slots, attaching buss on top of tabs on the current collector, and the like.

Fig. 10 is a portion of a top view (i.e., viewed from the height direction H) of the stacked battery cells 900. The portion of the stacked battery cell 900 shown in fig. 9 includes one electrode structure 202 and two counter electrode structures 204. In this example, the electrode structure 202 is an anode electrode structure and the counter electrode structure 204 is a cathode electrode structure.

Referring to fig. 11A and 11B, after forming the stacked battery cell 900, the stacked battery cell 900 proceeds to a packaging station 1100, wherein the stacked battery cell 900 is coated with an insulating packaging material 1101, such as a multi-layer aluminum polymer material, plastic, or the like, to form a battery package 1102. In one embodiment, battery package 1102 is evacuated using a vacuum and filled with electrolyte material through openings (not shown). The insulating packaging material may be sealed around the stacked battery cells 900 using heat sealing, laser welding, adhesives, or any suitable sealing method. After sealing, the battery insulating packaging material forms a sealed enclosure. The ends of the bus bars 208 and 210 remain exposed and uncovered by the battery package 1102, and the exposed ends serve as electrode terminals and counter electrode terminals located outside the sealed battery housing. The exposed ends of the bus bars allow a user to connect the bus bars to a device to be powered or to a battery charger. In other embodiments, separate external and counter electrode terminals are welded to bus bars 208 and 210 and positioned outside sealed battery package 1102. In some embodiments, the connection between such external electrode terminals and the counter electrode terminals is located within the battery package 1102, and the ends of the bus bars 208, 210 do not extend outside of the battery package 1102.

Referring now to fig. 12, a method for determining the thermal runaway current (I) used in equation (6) may be performed _tr ) Wet (i.e., the unit cell contains a liquid electrolyte) Forced Internal Short Circuit (FISC) measurement. The FISC assay is an iterative test. Testing was performed on an electrode assembly comprising n unit cells (where n is a positive integer). Each unit cell comprises a single electrode structure 202 adjacent a single counter electrode 204 with a separator 205 therebetween and a current limiter 206. The first iteration is performed with an electrode assembly, where n=1 (i.e., there is a single unit cell), that is electrically disconnected from any other electrode structure 202, 204. Fig. 12 shows an electrode assembly to be tested comprising a single unit cell 1200. Note that fig. 12 is not drawn to scale. For testing, the conductive particles 1202 are positioned in the region between the fully charged positive and negative electrodes of the unit cell (e.g., on the separator structure 205 between the electrode structure 202 and the counter electrode structure 204). In one example, the conductive particles 1202 are L-shaped nickel particles of 2mm x 0.2mm x 0.1mm. In other embodiments, the conductive particles 1202 may have any other suitable shape and/or may be made of any other suitable conductive material. The servo motor 1204 displaces a 5mm x 5mm flat acrylic ram 1206 to a unit cell at a speed of 1.0 mm/s The embedded conductive particles on element 1200 are located at the locations. This causes the conductive particles 1202 to electrically connect the electrode structure 202 and the counter electrode structure 204 in the form of a short circuit. The servo motor 1204 continues to displace the ram 1206 until the voltage of the unit cell drops by more than 80%. If the unit cell 1200 experiences a catastrophic failure (e.g., the unit cell 1200 fires or explodes), the test is stopped. If a single unit cell 1200 fails the test, the configuration of the failed unit cell does not use this test to determine the thermal runaway current (I _tr ) And for this configuration of the unit cell 1200, different tests, estimations, simulations, etc. must be performed to determine the thermal runaway current (I _tr ). Furthermore, if a single unit cell 1200 fails the test, the configuration of the failed unit cell may not be a good candidate for use with the current limiter described herein, as the resistance required by the current limiter to properly limit the current will likely be high enough to produce undesirable energy losses under normal charge and discharge.

If the unit cell 1200 does not experience a catastrophic failure, the unit cell 1200 configuration is incremented by 1 through the first iteration, n, and a new assembly comprising two unit cells (i.e., n=2) is assembled, wherein one of the unit cells is configured with conductive particles 1202, as discussed above for the first step. The FISC test was repeated for this new assembly having two unit cells. If the new assembly passes the test, the above steps in this paragraph are performed again. That is, a new assembly having n=n+1 unit battery cells is assembled with one of the unit battery cells including the conductive particles, and the FISC test is performed again. The worst case forced internal short circuit resistance is given in each step by:

R _s,WCFISC (n)＝R _{20kHz(Vtoc,n)} (9)

In this example, a 20kHz impedance is used, but any other suitable non-zero frequency impedance may be used. This iteration is repeated until the electrode assembly fails the test. Once saidOne of the electrode assemblies fails the test and the test is stopped. Determining a thermal runaway current (I) using the number of unit cells from a last successful iteration (i.e., an electrode assembly having current values of n-1 unit cells) _tr ). Thermal runaway current (I) _tr ) This is given by:

then, the thermal runaway current (I) determined from equation (10) is used in inequality (6) _tr ) To determine the resistance required for each current limiter 206 and may produce an electrode assembly containing current limiters 206 each having a determined resistance.

Although discussed above as starting from a single unit cell and n=1, the above determination may begin with any suitable non-zero number of unit cells. For example, if a particular unit cell configuration is expected (e.g., estimated, calculated, etc.) to fail the test when n=4, the test may begin when n=3, with the electrode assembly containing three unit cells.

Used as R in equation (6) _s The actual short circuit resistance of (c) may be determined using a dry FISC assay. The dry FISC assay is similar to the FISC assay discussed above, but is performed on one or more unit cells. In a dry FISC assay, a FISC is performed on one or more unit cells without any electrolyte using the assemblies and techniques described above with reference to fig. 12. That is, the unit cell (including the single electrode structure 202 adjacent to the single counter electrode 204 having the separator 205) has the conductive particles 1202 positioned in the region between the positive and negative electrodes of the unit cell (e.g., on the separator structure 205 between the electrode structure 202 and the counter electrode structure 204), and the press head 1206 crushes the unit cell to electrically connect the conductive particles 1202 to the electrode structure 202 and the counter electrode structure 204 in a short-circuited form. Then, the actual short circuit resistance of the short-circuited unit battery cell is measured, and can be used in equation (6).

Fig. 13 is a simplified diagram of a portion of another electrode assembly 1300 in a battery for cycling between a charged state and a discharged state. The electrode assembly 1300 includes similar components to those described above and, unless otherwise specified, the components are identical. The counter electrode structure group, the separator structure group, and the counter electrode bus bar are omitted from the drawing for clarity. The current limiter group 206 in the electrode assembly 1300 has fewer members than the electrode structure group 202. The electrode structure groups are divided into groups 1302 of electrode structures 202. Each group 1302 of electrode structures 202 contains two electrode structures 202 in fig. 13. In other embodiments, the group 1302 may contain any number of electrode structures 202, so long as the group contains more than one electrode structure 202. Each electrode structure 202 in a group 1302 is electrically connected in parallel to the other electrode structures 202 in its group 1302. The parallel connection of electrode structures 202 in group 1302 is connected to electrode buss 208 through a single current limiter 206. That is, all of the electrode structures in the group 1302 share a single current limiter 206. Other embodiments may additionally or alternatively include similar grouping arrangements of counter electrode structures 204 sharing a single current limiter 206. Further, in some embodiments, some of the electrode structures 202 and/or some of the counter electrode structures 204 in an electrode assembly may be grouped as described above, while other electrode structures 202 and/or counter electrode structures 204 in the assembly are not grouped and each have their own current limiter 206.

The resistance of the current limiter 206 in the electrode assembly 1300 is determined by the variation of inequality (6) discussed above. Specifically, the resistance of the shared current limiter 206 in the electrode assembly 1300 is determined to satisfy:

where n is the number of unit cell units (or the number of electrode structures 202) in the group 1302.

In some embodiments, the resistance of the current limiter 206 is defined by the relationship between the resistance of the current limiter and the cell resistance of the unit cell. Specifically, each unit cell has a cell resistance R1 in a normal operating temperature range between minus 30 degrees celsius (°c) and 80 ℃. Each current limiter has a resistance R2 such that:

R2/R1 > 0.01 (12)

when the electrode assembly is within the normal operating temperature range. The exact value of the ratio of R2/R1 may vary depending on the capacity and/or voltage of the battery. In example embodiments, R2/R1 is approximately equal to 0.5, 0.95, or 0.0275. In some embodiments, R2/R1 may be greater than 0.1, greater than 0.5, greater than 0.95, or greater than 0.1.

The following examples are provided to illustrate aspects of the disclosure, but are not intended to be limiting and other aspects and/or embodiments may also be provided.

Embodiment 1. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. Each member of the electrode structure group includes an electrode active material and an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode active material and a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. The current limiter cluster includes at least ten current limiters. Each of the electrode collectors is electrically connected to the electrode buss through a member of the current limiter cluster, wherein the resistance of each member of the current limiter cluster is greater than or equal to 0.25 ohms (Ω) at a temperature of 25 degrees celsius (deg.c).

Embodiment 2 an electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising: an electrode structure population, each member of the electrode structure population comprising an electrode active material and an electrode current collector; an electrode bus bar to which the electrode current collectors of each member of the electrode structure group are electrically connected in parallel; a population of counter electrode structures, each member of the population of counter electrode structures comprising a counter electrode active material and a counter electrode current collector; a counter electrode bus bar to which the counter electrode current collectors of each member of the counter electrode structure group are electrically connected in parallel; a current limiter bank. Each member of the current limiter group electrically connects the electrode current collector of each member of the electrode structure group to the electrode buss, wherein the resistance of each member of the current limiter group is greater than or equal to 0.25 ohm (Ω) at a temperature of 25 degrees celsius (deg.c).

Example 3. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of separator structures for electrically isolating the population of electrode structures and the population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. Each member of the electrode structure group includes an electrode active material and an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode active material and a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. Each member of the current limiter group is electrically connected between a different electrode current collector and the electrode bus, wherein the resistance of each member of the current limiter group is greater than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (deg.c).

Example 4. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of separator structures for electrically isolating the population of electrode structures and the population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. Each member of the electrode structure group includes an electrode active material and an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode active material and a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. Each member of the current limiter group is positioned between and electrically connected to a different electrode current collector and the electrode buss, wherein the resistance of each member of the current limiter group is greater than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (deg.c).

Example 5 an electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of separator structures for electrically isolating the population of electrode structures and the population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. The electrode assembly has a full charge capacity C at 25 ℃, a current threshold I that may cause the electrode assembly to fail _Th And a voltage difference V exists between the electrode structure group member and the counter electrode structure group member. The electrode structure group members each have an electrode structure resistance and include an electrode active material and an electrode current collector, the electrode current collectors contained by the electrode structure group members being electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode active material and a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. Each member of the current limiter group is electrically connected between a different electrode current collector and the electrode buss, wherein each member of the current limiter group has a function of limiting the current through its associated member of the electrode structure group to less than I at a temperature of 25 degrees celsius (c) _Th And the resistance is determined as a function of V, the electrode structure resistance of the associated electrode structure group member, the short circuit resistance between the associated electrode structure group member and a member of the pair of electrode structure groups, and the number of electrode structure group members connected to the electrode buss.

Example 6 the electrode Assembly of example 5 wherein I _Th Greater than or equal to 8 amps and less than or equal to 12 amps.

Example 7 the electrode Assembly of example 5 or example 6, wherein I _Th Is 8.0 amps.

Embodiment 8. The electrode assembly of any one of embodiments 5 to 7, wherein V is 4.35 volts.

Example 9 an electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of separator structures for electrically isolating the population of electrode structures and the population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. The electrode assembly has a full charge capacity C at 25 degrees celsius (°c). Each member of the electrode structure group includes an electrode active material and an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode active material and a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. The current limiter group is positioned in electrical connection between the electrode buss and each electrode current collector of the electrode group members, wherein at a temperature of 25 ℃, (i) each member of the current limiter group comprises a resistance that limits the amount of current that can flow between the electrode buss and its associated electrode current collector to a maximum of 8 amps, and (ii) when current flows between the electrode buss and each member of the subset of electrode current collectors to charge or discharge the electrode assembly at a C-rate of 1C, the voltage drop across each member of the current limiter group is no more than 20mV.

Example 9.1. An electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range between minus 30 degrees celsius (°c) and 80 ℃, the electrode assembly comprising a unit cell population, an electrode buss, a counter electrode buss, and a current limiter population. Each member of the unit cell group has a cell resistance R1, and includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer. For each member of the group of unit battery cells, (a) the electrode collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) a member of the group of current limiters is electrically connected between (i) the electrode collector and the electrode bus bar or (ii) the counter electrode collector and the counter electrode bus bar. Each member of the current limiter population has a resistance R2 such that R2/R1>0.01 when the electrode assembly is within the normal operating temperature range.

Example 9.2 an electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range between minus 20 degrees celsius (°c) and 80 ℃, the electrode assembly comprising a unit cell population, a current limiter population, an electrode bus, and a counter electrode bus. Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer. For each member of the group of unit battery cells, (a) the electrode current collectors of the electrode structures are electrically connected to the electrode bus bars, (b) the counter electrode current collectors of the counter electrode structures are electrically connected to the counter electrode bus bars, and (c) at least one member of the group of current limiters is electrically connected between (i) the electrode current collectors and the electrode bus bars or (ii) the counter electrode current collectors and the counter electrode bus bars. For each unit cell, when the electrode assembly is within the normal operating temperature range sufficient to substantially continuously limit current through the unit cell to a non-zero current less than a threshold current I, the at least one member of the current limiter population has a resistance, the threshold current being less than a current that would induce thermal runaway of the unit cell until the electrode assembly is discharged.

Embodiment 10. The electrode assembly of any one of embodiments 5 to 9.2, wherein the resistance of each member of the current limiter population is greater than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (°c).

Embodiment 11. The electrode assembly of any one of embodiments 3-10, wherein the resistance of each member of the current limiter population does not increase at a temperature above 25 ℃.

Embodiment 12. The electrode assembly of any one of embodiments 1 to 11, wherein the current limiter population comprises a conductive adhesive.

Embodiment 13. The electrode assembly of embodiment 12 wherein the conductive adhesive comprises a single layer of conductive adhesive and each member of the current limiter population comprises a different portion of the single layer of conductive adhesive.

Embodiment 14. The electrode assembly of embodiment 13, wherein the single layer of conductive adhesive is disposed on the electrode bus.

Embodiment 15. The electrode assembly of embodiment 12, wherein the conductive adhesive of each member of the current limiter group is physically separated from the conductive adhesive of each other member of the current limiter group.

Embodiment 16. The electrode assembly of embodiment 15, a conductive adhesive is disposed on a portion of each member of the electrode current collector population.

Embodiment 17. The electrode assembly of any of embodiments 12-16, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

Embodiment 18. The electrode assembly of embodiment 17 wherein the conductive material comprises carbon black.

Embodiment 18.1. The electrode assembly of embodiment 17 wherein the conductive material comprises metal coated carbon fibers.

Embodiment 18.2. The electrode assembly of embodiment 18.1 wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

Embodiment 18.3. The electrode assembly of embodiment 18.1 or 18.2 wherein the metal-coated carbon fiber has a length and a diameter, and an aspect ratio of the length to the diameter is equal to or greater than 10:1.

Example 18.4 the electrode assembly of example 18.3, wherein the aspect ratio of the length to the diameter is between 10:1 and 10,000:1, inclusive.

Example 18.5 the electrode assembly of example 18.3, wherein the aspect ratio of the length to the diameter is between 50:1 and 5,000:1, inclusive.

Example 18.6 the electrode assembly of example 18.3, wherein the aspect ratio of the length to the diameter is between 100:1 and 2,000:1, inclusive.

Example 18.7 the electrode assembly of example 18.3, wherein the aspect ratio of the length to the diameter is about 850.

Embodiment 19. The electrode assembly of embodiment 17, wherein the conductive material comprises nickel particles.

Embodiment 20. The electrode assembly of embodiment 17, wherein the conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

Embodiment 21. The electrode assembly of embodiment 17 wherein the conductive material comprises metal particles.

Embodiment 22. The electrode assembly of any of embodiments 12-21, wherein the conductive adhesive comprises a hot melt adhesive polymer.

Embodiment 22.1. The electrode assembly of any one of embodiments 12-21, wherein the conductive adhesive has a melt flow index between 0.1 grams (g)/10 minutes (min) to 1000g/10min, as determined according to astm d 1238 at 190 ℃.

Embodiment 22.2. The electrode assembly of embodiment 22.1 wherein the melt flow index is between 0.1g/10min to 100g/10 min.

Embodiment 22.3. The electrode assembly of embodiment 22.1 wherein the melt flow index is between 0.5g/10min to 20g/10 min.

Embodiment 22.4. The electrode assembly of any one of embodiments 12-22.3, wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

Example 22.5 the electrode assembly of example 22.4, wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

Example 22.6 the electrode assembly of example 22.4, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.

Embodiment 23. The electrode assembly of any one of embodiments 12 to 22.6, wherein the conductive adhesive has a resistivity of greater than or equal to 0.01Ω -cm.

Embodiment 24. The electrode assembly of any of embodiments 12-23, wherein the conductive adhesive has a resistivity of less than or equal to 1.0 Ω -cm.

Embodiment 25. The electrode assembly of any of embodiments 12 to 24, wherein the conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

Embodiment 26. The electrode assembly of any of embodiments 12 to 24, wherein the conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

Embodiment 27. The electrode assembly of any of embodiments 12 to 24, wherein the conductive adhesive comprises a functionalized polyethylene.

Embodiment 28. The electrode assembly of any of embodiments 12 to 24, wherein the conductive adhesive comprises functionalized polypropylene.

Embodiment 29. The electrode assembly of any one of embodiments 1-11, wherein each member of the current limiter population comprises a conductive film.

Embodiment 30. The electrode assembly of any one of embodiments 1 to 29, wherein each member of the current limiter population is physically located between the electrode buss and its associated electrode current collector.

Embodiment 31. The electrode assembly of any one of embodiments 1 to 30, further comprising a further population of current limiters, each member of the further population of current limiters being electrically connected between a different pair of electrode current collectors and the pair of electrode buss.

Embodiment 32. The electrode assembly of embodiment 31, wherein the resistance of each member of the additional current limiter group is greater than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (degrees celsius).

Embodiment 33. The electrode assembly of embodiment 31 wherein the resistance of each member of the additional current limiter group is less than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (degrees celsius).

Embodiment 34 the electrode assembly of any one of embodiments 31-33, wherein the resistance of each member of the second current limiter group does not increase at a temperature above 25 ℃.

Embodiment 35 the electrode assembly of any one of embodiments 31-34, wherein the additional current limiter population comprises additional conductive adhesive.

Embodiment 36. The electrode assembly of embodiment 35, wherein the additional conductive adhesive comprises an additional adhesive polymer having additional conductive material suspended therein.

Embodiment 37. The electrode assembly of embodiment 36, wherein the additional conductive material comprises carbon black.

Embodiment 37.1. The electrode assembly of embodiment 36, wherein the additional conductive material comprises metal-coated carbon fibers.

Embodiment 37.2. The electrode assembly of embodiment 37.1 wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

Embodiment 37.3. The electrode assembly of embodiment 37.1 or 37.2 wherein the metal-coated carbon fiber has a length and a diameter, and an aspect ratio of the length to the diameter is equal to or greater than 10:1.

Example 37.4 the electrode assembly of example 37.3, wherein the aspect ratio of the length to the diameter is between 10:1 and 10,000:1, inclusive.

Example 37.5 the electrode assembly of example 37.3, wherein the aspect ratio of the length to the diameter is between 50:1 and 5,000:1, inclusive.

Example 37.6 the electrode assembly of example 37.3, wherein the aspect ratio of the length to the diameter is between 100:1 and 2,000:1, inclusive.

Example 37.7 the electrode assembly of example 37.3, wherein the aspect ratio of the length to the diameter is about 850.

Embodiment 38. The electrode assembly of embodiment 36, wherein the additional conductive material comprises nickel particles.

Embodiment 39. The electrode assembly of embodiment 36, wherein the additional conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

Embodiment 40. The electrode assembly of embodiment 36, wherein the additional conductive material comprises metal particles.

Embodiment 41. The electrode assembly of embodiment 36, wherein the additional conductive material and the conductive material are the same type of conductive material.

Embodiment 42. The electrode assembly of any one of embodiments 35-41 wherein the additional conductive adhesive comprises a hot melt adhesive polymer.

Embodiment 42.1. The electrode assembly of any one of embodiments 35-41, wherein the additional conductive adhesive has a melt flow index of between 0.1 grams (g)/10 minutes (min) to 1000g/10min as determined according to astm d 1238 at 190 ℃.

Embodiment 42.2. The electrode assembly of embodiment 42.1, wherein the melt flow index is between 0.1g/10min to 100g/10 min.

Embodiment 42.3 the electrode assembly of embodiment 42.1, wherein the melt flow index is between 0.5g/10min to 20g/10 min.

Embodiment 42.4 the electrode assembly of any one of embodiments 35-42.3, wherein the additional conductive adhesive has a melting point between 40 ℃ and 300 ℃.

Example 42.5 the electrode assembly of example 42.4, wherein the melting point of the additional conductive adhesive is between 60 ℃ and 200 ℃.

Example 42.6 the electrode assembly of example 42.4, wherein the melting point of the additional conductive adhesive is between 70 ℃ and 165 ℃.

Embodiment 43. The electrode assembly of any one of embodiments 35-42.6, wherein the additional conductive adhesive has a resistivity greater than or equal to 0.01 Ω -cm.

Embodiment 44 the electrode assembly of any one of embodiments 35-43, wherein the additional conductive adhesive has a resistivity of less than or equal to 1.0 Ω -cm.

Embodiment 45 the electrode assembly of any one of embodiments 35 to 44, wherein the additional conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

Embodiment 46. The electrode assembly of any of embodiments 35 to 44, wherein the additional conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

Embodiment 47. The electrode assembly of any one of embodiments 35-44, wherein the additional conductive adhesive comprises a functionalized polyethylene.

Embodiment 48. The electrode assembly of any one of embodiments 35-44, wherein the additional conductive adhesive comprises functionalized polypropylene.

Embodiment 49 the electrode assembly of any one of embodiments 31-34, wherein each member of the additional current limiter population comprises a conductive film.

Embodiment 50. The electrode assembly of any one of embodiments 31-49, wherein each member of the additional current limiter population is physically located between the electrode buss and its associated electrode current collector.

Embodiment 51. The electrode assembly of any one of embodiments 1 to 50, further comprising a further population of electrode structures, each member of the further population of electrode structures comprising the electrode active material and a further electrode current collector, the further electrode current collector being electrically connected in parallel to the electrode buss and not to a member of the current limiter population.

Embodiment 52 the electrode assembly of any one of embodiments 1-51, wherein the electrode structure comprises a cathode structure, the electrode active material comprises a cathode active material, the electrode current collector comprises a cathode current collector, and the electrode buss comprises a cathode buss.

Embodiment 53. The electrode assembly of any one of embodiments 1 to 51, wherein the electrode structure comprises an anode structure, the electrode active material comprises an anode active material, the electrode current collector comprises an anode current collector, and the electrode buss comprises a cathode buss.

Embodiment 54. A secondary battery comprising a sealed battery housing, the electrode assembly of any of the preceding embodiments within the sealed housing, and an electrode terminal and a counter electrode terminal located outside the sealed battery housing.

Example 55. A secondary battery having a rated capacity C for cycling between a charged state and a discharged state, the secondary battery comprising (i) a sealed battery enclosure, (ii) an electrode assembly comprising a population of current limiters within the sealed enclosure, and (iii) an electrode terminal and a counter electrode terminal external to the sealed battery enclosure. The electrode assembly has mutually perpendicular transverse, longitudinal and vertical axes corresponding to the x-, y-and z-axes, respectively, of an imaginary three-dimensional cartesian coordinate system, and comprises (i) at least 10 groups of electrode structures and at least 10 groups of counter electrode structures arranged in alternating sequence in the longitudinal direction, (ii) an electrode busbar electrically connected to the electrode terminals, (iii) a counter electrode busbar electrically connected to the counter electrode terminals, and (iv) an electrically insulating membrane material between the electrode groups and members of the counter electrode groups, wherein (v) each member of the electrode groups is electrically connected to the electrode busbar in parallel, (vi) the electrode busbar has a length and a cross-sectional area and is adapted to carry current from the electrode terminals to the electrode groups and to carry current from the electrode groups to the electrode terminals, and (viii) each member of the counter electrode groups is electrically connected to the counter electrode busbar in parallel, and (viii) the counter electrode busbar has a length and a cross-sectional area and is adapted to carry current from the counter electrode groups to the electrode terminals. Each member of the electrode population includes an electrode current collector having a proximal end, a distal end, a length extending from its proximal end to its distal end, a cross-sectional area along its length, and a layer of electrode active material on a surface of the electrode current collector, the electrode current collector proximal end being electrically connected to the electrode buss. Each member of the counter electrode group includes a counter electrode collector and a counter electrode active material layer on a surface of the counter electrode collector. The current limiter cluster is electrically connected between the electrode buss and the electrode current collector, wherein the resistance of each member of the current limiter cluster is greater than 0.25 ohm (Ω) at a temperature of 25 degrees celsius (deg.c).

Embodiment 56 the secondary battery of embodiment 55 wherein the resistance of each member of the current limiter group does not increase at temperatures above 25 ℃.

Embodiment 57. The secondary battery of embodiment 56 or embodiment 57, wherein the current limiter group comprises a conductive adhesive.

Embodiment 58 the secondary battery of embodiment 57 wherein the conductive adhesive comprises a single layer of conductive adhesive and each member of the current limiter group comprises a different portion of the single layer of conductive adhesive.

Embodiment 59. The secondary battery of embodiment 58, wherein the single layer of conductive adhesive is disposed on the electrode bus.

Embodiment 60. The secondary battery of embodiment 57, wherein the conductive adhesive of each member of the current limiter group is physically separated from the conductive adhesive of each other member of the current limiter group.

Embodiment 61. The secondary battery of embodiment 60, a conductive adhesive is disposed on a portion of each member of the electrode current collector group.

Embodiment 62 the secondary battery of any one of embodiments 57-61, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

Embodiment 63. The secondary battery of embodiment 62 wherein the conductive material comprises carbon black.

Embodiment 63.1 the secondary battery of embodiment 62, wherein the conductive material comprises metal-coated carbon fibers.

Embodiment 63.2 the secondary battery of embodiment 63.1 wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

Embodiment 63.3. The secondary battery of embodiment 63.1 or 63.2, wherein the metal-coated carbon fibers have a length and a diameter, and an aspect ratio of the length to the diameter is equal to or greater than 10:1.

Example 63.4 the secondary battery of example 63.3, wherein the aspect ratio of the length to the diameter is between 10:1 and 10,000:1, inclusive.

Example 63.5 the secondary battery of example 63.3, wherein the aspect ratio of the length to the diameter is between 50:1 and 5,000:1, inclusive.

Example 63.6 the secondary battery of example 63.3, wherein the aspect ratio of the length to the diameter is between 100:1 and 2,000:1, inclusive.

Example 63.7. The secondary battery of example 63.3, wherein the aspect ratio of the length to the diameter is about 850.

Embodiment 64 the secondary battery of embodiment 62 wherein the conductive material comprises nickel particles.

Embodiment 65 the secondary battery of embodiment 62, wherein the electrically conductive material comprises one or more of the following: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

Embodiment 66. The secondary battery of embodiment 62 wherein the conductive material comprises metal particles.

Embodiment 67 the secondary battery of any one of embodiments 57-66, wherein the conductive adhesive comprises a hot melt adhesive polymer.

Embodiment 67.1. The secondary battery of any one of embodiments 57-66, wherein the conductive adhesive has a melt flow index between 0.1 grams (g)/10 minutes (min) to 1000g/10min, as determined according to astm d 1238 at 190 ℃.

Embodiment 67.2 the secondary battery of embodiment 67.1 wherein the melt flow index is between 0.1g/10min to 100g/10 min.

Embodiment 67.3 the secondary battery of embodiment 67.1, wherein the melt flow index is between 0.5g/10min to 20g/10 min.

Embodiment 67.4 the secondary battery of any one of embodiments 57-67.3, wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

Embodiment 67.5 the secondary battery of embodiment 67.4, wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

Embodiment 67.6 the secondary battery of embodiment 67.4, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.

Embodiment 68 the secondary battery of any one of embodiments 57-67.6, wherein the conductive adhesive has a resistivity of greater than or equal to 0.01 Ω -cm.

Embodiment 69 the secondary battery of any one of embodiments 57-68 wherein the conductive adhesive has a resistivity of less than or equal to 1.0 Ω -cm.

Embodiment 70. The secondary battery of any one of embodiments 57 to 69, wherein the conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

Embodiment 71 the secondary battery of any one of embodiments 57 to 69, wherein the conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

Embodiment 72 the secondary battery of any one of embodiments 57-69 wherein the conductive adhesive comprises a functionalized polyethylene.

Embodiment 73 the secondary battery of any one of embodiments 57-69 wherein the conductive adhesive comprises functionalized polypropylene.

Embodiment 74. The secondary battery of embodiment 55 or embodiment 56, wherein each member of the current limiter group comprises a conductive film.

Embodiment 75 the secondary battery of any one of embodiments 55-74 wherein each member of the current limiter population is physically located between the electrode buss and its associated electrode current collector.

Embodiment 76 the secondary battery of any one of embodiments 55-75 wherein the electrode assembly further comprises a further population of current limiters, each member of the further population of current limiters being electrically connected between a different pair of electrode current collectors and the pair of electrode buss.

Embodiment 77. The secondary battery of embodiment 76, wherein the resistance of each member of the additional current limiter group is greater than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (°c).

Embodiment 78. The secondary battery of embodiment 76, wherein the resistance of each member of the additional current limiter group is less than 0.25 ohms (Ω) at a temperature of 25 degrees celsius (°c).

Embodiment 79 the secondary battery of any one of embodiments 76-78 wherein the resistance of each member of the second current limiter group does not increase at a temperature greater than 25 ℃.

Embodiment 80. The secondary battery of any one of embodiments 76-79, wherein the additional current limiter group comprises an additional conductive adhesive.

Embodiment 81. The secondary battery of embodiment 80 wherein the additional conductive adhesive comprises an additional adhesive polymer having additional conductive material suspended therein.

Embodiment 82. The secondary battery of embodiment 81 wherein the additional conductive material comprises carbon black.

Embodiment 82.1. The secondary battery of embodiment 81 wherein the additional conductive material comprises metal-coated carbon fibers.

Embodiment 82.2 the secondary battery of embodiment 82.1 wherein the metal-coated carbon fiber comprises a nickel-coated carbon fiber.

Embodiment 82.3 the secondary battery of embodiment 82.1 or 82.2, wherein the metal-coated carbon fiber has a length and a diameter, and an aspect ratio of the length to the diameter is equal to or greater than 10:1.

Example 82.4 the secondary battery of example 82.3, wherein the aspect ratio of the length to the diameter is between 10:1 and 10,000:1, inclusive.

Example 82.5 the secondary battery of example 82.3, wherein the aspect ratio of the length to the diameter is between 50:1 and 5,000:1, inclusive.

Example 82.6 the secondary battery of example 82.3, wherein the aspect ratio of the length to the diameter is between 100:1 and 2,000:1, inclusive.

Example 82.7 the secondary battery of example 82.3, wherein the aspect ratio of the length to the diameter is about 850.

Embodiment 83 the secondary battery of embodiment 81 wherein the additional conductive material comprises nickel particles.

Embodiment 84 the secondary battery of embodiment 81 wherein the additional conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

Embodiment 85 the secondary battery of embodiment 81 wherein the additional conductive material comprises metal particles.

Embodiment 86. The secondary battery of embodiment 81 wherein the additional conductive material and the conductive material are the same type of conductive material.

Embodiment 87 the secondary battery of any one of embodiments 80-86, wherein the additional conductive binder comprises a hot melt binder polymer.

Embodiment 87.1 the secondary battery of any one of embodiments 80-86, wherein the melt flow index of the additional conductive adhesive is between 0.1 grams (g)/10 minutes (min) to 1000g/10min as determined according to astm d 1238 at 190 ℃.

Embodiment 87.2 the secondary battery of embodiment 87.1 wherein the melt flow index is between 0.1g/10min and 100g/10 min.

Embodiment 87.3 the secondary battery of embodiment 87.1 wherein the melt flow index is between 0.5g/10min and 20g/10 min.

Embodiment 87.4 the secondary battery of any one of embodiments 80-87.3, wherein the additional conductive adhesive has a melting point between 40 ℃ and 300 ℃.

Embodiment 87.5 the secondary battery of embodiment 87.4 wherein the melting point of the additional conductive adhesive is between 60 ℃ and 200 ℃.

Embodiment 87.6 the secondary battery of embodiment 87.4 wherein the melting point of the additional conductive adhesive is between 70 ℃ and 165 ℃.

Embodiment 88 the secondary battery of any one of embodiments 80 to 87.6, wherein the additional conductive adhesive has a resistivity of greater than or equal to 0.01Ω -cm.

Embodiment 89 the secondary battery of any one of embodiments 80-88, wherein the additional conductive adhesive has a resistivity of less than or equal to 1.0 Ω -cm.

Embodiment 90 the secondary battery of any one of embodiments 80-89, wherein the additional conductive adhesive comprises one of ethylene-co-acrylic acid, an ionomer of ethylene-co-acrylic acid, and a polymer of ethylene-co-acrylic acid.

Embodiment 91 the secondary battery of any of embodiments 80-89, wherein the additional conductive adhesive comprises one of ethylene-co-methacrylic acid, an ionomer of ethylene-co-methacrylic acid, and a polymer of ethylene-co-methacrylic acid.

Embodiment 92 the secondary battery of any one of embodiments 80-89, wherein the additional conductive adhesive comprises a functionalized polyethylene.

Embodiment 93 the secondary battery of any one of embodiments 80-89, wherein the additional conductive adhesive comprises functionalized polypropylene.

Embodiment 94 the secondary battery of any one of embodiments 76-79, wherein each member of the additional current limiter group comprises a conductive film.

Embodiment 95 the secondary battery of any one of embodiments 76-94, wherein each member of the additional current limiter population is physically located between the electrode buss and its associated electrode current collector.

Embodiment 96 the secondary battery of any one of embodiments 55-95, wherein the electrode assembly further comprises a further population of electrode structures, each member of the further population of electrode structures comprising the electrode active material and a further electrode current collector, the further electrode current collectors being electrically connected in parallel to the electrode buss and not to a member of the current limiter population.

Embodiment 97 the secondary battery of any one of embodiments 55-96, wherein the electrode structure comprises a cathode structure, the electrode active material comprises a cathode active material, the electrode current collector comprises a cathode current collector, and the electrode buss comprises a cathode buss.

Embodiment 98 the secondary battery of any one of embodiments 55-96, wherein the electrode structure comprises an anode structure, the electrode active material comprises an anode active material, the electrode current collector comprises an anode current collector, and the electrode buss comprises a cathode buss.

Embodiment 99. A method of testing an electrode unit cell having a current limiter for an electrode assembly cycling between a charged state and a discharged state, the electrode unit cell comprising an electrode structure, a counter electrode structure, and a spacer located between the electrode structure and the counter electrode structure, the current limiter being electrically connected to the electrode structure, wherein the electrode unit cell has a capacitance C and a voltage V. The method includes electrically connecting a current limiter to the electrode structure, wherein a resistance of the current limiter is greater than or equal to 0.25 ohms (Ω) at a temperature of 25 degrees celsius (deg.c). Conductive particles are inserted at positions of the electrode unit cells between the electrode structure and the counter electrode structure, and a pressing head is positioned above the positions of the electrode unit cells where the conductive particles are inserted. The ram presses into the electrode unit cells at a speed of 1.0 millimeters (mm) per second while preventing the electrode unit cells from moving to push the conductive particles through the spacer and into contact with both the electrode unit cells and the counter electrode unit cells. The electrode unit battery cell having the current limiter does not pass the test when the electrode unit battery cell catches fire, and the electrode unit battery cell having the current limiter passes the test when the electrode unit battery cell does not catch fire.

Embodiment 100. The method of embodiment 99 wherein pressing the crimp into the electrode unit cell comprises pressing the crimp into the electrode unit cell until a voltage drop of the voltage V of greater than 80% is observed.

Embodiment 101. The method of embodiment 99 or embodiment 100, wherein inserting the conductive particles comprises inserting nickel particles.

Embodiment 102. The method of embodiment 101 wherein inserting the nickel particles comprises inserting nickel particles shaped like 2.0mm x 0.2mm x 0.1mm nickel particles of the english letter "L".

Embodiment 103. The method of any of embodiments 99 to 102, further comprising: when it is determined that the electrode unit cell fails the test, attaching a different current limiter to a similar electrode unit cell having the same capacity C and the same voltage V as the electrode unit cell, the different current limiter having a greater resistance than the current limiter at a temperature of 25 ℃; inserting similar conductive particles at positions of the similar electrode unit cells between the similar electrode structures and the similar counter electrode structures of the similar electrode unit cells; positioning the ram above the locations of the like electrode unit cells where the like conductive particles are inserted; pressing the ram into the like electrode unit cell at a speed of 1.0mm per second while preventing the like electrode unit cell from moving; when the similar electrode unit battery cells catch fire, it is determined that the similar electrode unit battery cells having the different current limiters do not pass the test, and when the similar electrode unit battery cells do not catch fire, it is determined that the similar electrode unit battery cells having the different current limiters pass the test.

Embodiment 104. A method of designing an electrode assembly for cycling between a charged state and a discharged state includes assembling an electrode unit cell having a type of electrode structure, a counter electrode structure, and a spacer positioned between the electrode structure and the counter electrode structure, the type being determined by a voltage generated by the electrode unit cell, a capacity of the electrode unit cell, and a material used to construct the electrode structure, the counter electrode structure, and the spacer. A current limiter is electrically connected to the electrode structure, wherein a resistance of the current limiter is greater than or equal to 0.25 ohm (Ω) at a temperature of 25 degrees celsius (°c). Conductive particles are inserted at positions of the electrode unit battery cells between the electrode structure and the counter electrode structure. The pressure head is positioned above the position of the electrode unit cell where the conductive particles are inserted. The ram presses into the electrode unit cells at a speed of 1.0 millimeters (mm) per second while preventing the electrode unit cells from moving to push the conductive particles through the spacer and into contact with both the electrode unit cells and the counter electrode unit cells. The electrode unit battery cell having the current limiter does not pass the test when the electrode unit battery cell catches fire, and the electrode unit battery cell having the current limiter passes the test when the electrode unit battery cell does not catch fire. When the electrode unit battery cells having the current limiters pass the test, an electrode structure including the electrode unit battery cell group of the type and a current limiter group, each of which is electrically connected to a different electrode unit battery cell, is assembled.

Embodiment 105. The method of embodiment 104, further comprising assembling a similar electrode unit cell having the same type as the electrode unit cell; electrically connecting a different current limiter to the similar electrode structure, wherein the different current limiter has a resistance greater than the current limiter at a temperature of 25 degrees celsius (°c); inserting similar conductive particles at the positions of the similar electrode unit cells; positioning the ram above the locations of the electrode-like unit cell cells where the conductive particles are inserted; pressing the ram into the like electrode unit cell at a speed of 1.0mm per second while preventing the like electrode unit cell from moving; determining that the similar electrode unit battery cells having the different current limiters do not pass the test when the similar electrode unit battery cells catch fire, and determining that the similar electrode unit battery cells having the different current limiters pass the test when the similar electrode unit battery cells do not catch fire; and assembling an electrode structure including a group of electrode unit cells having the same type as the electrode unit cells and a group of different current limiters, each of the different current limiters being electrically connected to a different electrode unit cell, when the similar electrode unit cells having the different current limiters pass the test.

Example 106 determination of thermal runaway Current I through electrode Unit cell _tr If an internal short circuit occurs in one of the electrode unit cells, the thermal runaway current can cause the electrode assembly including the electrode unit cell group to fail, each electrode unit cell including an electrode structure, a counter electrode structure, and a separator structure between the electrode structure and the counter electrode structure. The method comprises the following steps: (a) In an electrode assembly of M unit battery cells electrically connected in parallel, inserting conductive particles at a position of one electrode unit battery cell located between the electrode structure and the counter electrode structure, wherein M is a positive integer; (b) Positioning a ram above the electrode assembly at a location where the conductive particles are inserted into the electrode unit cell; (c) Pressing the indenter into the electrode at a rate of 1.0 millimeters (mm) per secondIn an assembly, the electrode assembly is simultaneously prevented from moving to push the conductive particles through the separator structure and into contact with both the electrode unit cell and the counter electrode unit cell; (d) Determining that the electrode assembly fails the test when the electrode assembly fires, and determining that the electrode assembly passes the test when the electrode assembly does not fire; (e) Increasing M by 1 when the electrode assembly passes the test, and repeating steps (a) through (e), and advancing to step (f) when the electrode assembly fails the test; and (f) determining the thermal runaway current I based on the electrode assembly including M-1 unit cells _tr 。

Embodiment 107 the method of embodiment 106 wherein the thermal runaway current I is determined based on the electrode assembly comprising M-1 unit cells _tr Comprises calculating the thermal runaway current I as a function of the voltage of the individual unit cell when fully charged and the short circuit resistance of the electrode unit cell into which the conductive particles are inserted when the electrode assembly comprises M-1 unit cells _tr 。

Embodiment 108. A method of designing an electrode assembly including a population of electrode unit cells for cycling between a charged state and a discharged state, the method comprising: (a) Assembling M electrode unit battery units, wherein each electrode unit battery unit comprises an electrode structure, a counter electrode structure and a diaphragm structure positioned between the electrode structure and the counter electrode structure, and M is a positive integer; (b) Electrically connecting M unit battery cells in parallel in the electrode assembly; (c) Inserting conductive particles at a position of one electrode unit cell located between the electrode structure and the counter electrode structure; (d) Positioning a ram above the electrode assembly at a location where the conductive particles are inserted into the electrode unit cell; (e) Pressing the ram into the electrode assembly while preventing movement of the electrode assembly to push the conductive particles through the separator structure and with the electrode unit cell and the counter electrode unit Both battery cells are in contact; (f) Determining that the electrode assembly fails the test when the electrode assembly fires, and determining that the electrode assembly passes the test when the electrode assembly does not fire; (g) Increasing M by 1 when the electrode assembly passes the test, and repeating steps (a) through (g), and advancing to step (h) when the electrode assembly fails the test; (h) Determining the thermal runaway current I based on the electrode assembly including M-1 unit cell _tr The method comprises the steps of carrying out a first treatment on the surface of the And (I) determining an increased resistance in series with each electrode structure when the electrode unit cell groups are assembled into an electrode assembly that limits current through individual electrode unit cells to less than the thermal runaway current I if a short circuit occurs in the individual electrode unit cells _tr 。

Embodiment 109 the method of embodiment 108 wherein the thermal runaway current I is determined based on the electrode assembly comprising M-1 unit cells _tr Comprises calculating the thermal runaway current I as a function of the voltage of the individual unit cell when fully charged and the short circuit resistance of the electrode unit cell into which the conductive particles are inserted when the electrode assembly comprises M-1 unit cells _tr 。

Embodiment 110 the method of embodiment 108 or 109 wherein the resistance to be increased is a current limiting resistance R satisfying the formula _cld ：

Wherein V is _TOC Is the voltage of the unit cell when fully charged, R _bl Is the resistance of each unit cell, R _s Is a short-circuit resistance of the electrode unit cell into which the conductive particles are inserted when the electrode assembly includes M-1 unit cell, and N is the number of electrode unit cells included in the electrode assembly.

Implementation of the embodimentsExample 111 an electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range includes an electrode structure population, a counter electrode structure population, a current limiter population, an electrode bus, and a counter electrode bus. Each member of the electrode structure group includes an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. Each of the electrode collectors is electrically connected to the electrode buss by a member of the current limiter cluster, wherein when the electrode assembly is in a state sufficient to limit current through the electrode collector to which the electrode assembly is attached to less than a current threshold I _tr Each member of the group of current limiters has a resistance when within the normal operating temperature range.

Embodiment 112. An electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range includes an electrode structure population, a counter electrode structure population, a current limiter population, an electrode bus, and a counter electrode bus. Each member of the electrode structure group includes an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. Each member of the current limiter group includes a conductive adhesive electrically connecting an electrode current collector to the electrode buss, the conductive adhesive having a resistance greater than zero ohms (Ω) when the electrode assembly is within the normal operating temperature range.

Embodiment 113 an electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. Each member of the electrode structure group includes an electrode current collector, and the electrode current collectors included in the electrode structure group members are electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. The current limiter cluster includes at least ten current limiters. Each of the electrode collectors is electrically connected to the electrode buss through a member of the current limiter cluster, wherein a resistance of each member of the current limiter cluster is greater than or equal to 0.25 ohms (Ω) when the electrode assembly is within the normal operating temperature range.

Embodiment 114. An electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range, the electrode assembly comprising a population of electrode structures, a population of counter electrode structures, a population of separator structures for electrically isolating the population of electrode structures and the population of counter electrode structures, a population of current limiters, an electrode buss, and a counter electrode buss. Each member of the electrode structure group has a thermal runaway current I _tr A threshold value. A voltage V exists between the electrode structure group member and the counter electrode structure group member. The electrode bus and the counter electrode bus have a terminal resistance in common. The electrode structure group members each have an electrode structure resistance and include an electrode collector, the electrode collectors included in the electrode structure group members being electrically connected in parallel to the electrode bus. Each member of the group of counter electrode structures includes a counter electrode current collector, the counter electrode current collectors included by the members of the group of counter electrode structures being electrically connected in parallel to the counter electrode bus bar. Each member of the current limiter group is electrically connected between a different electrode current collector and the electrode buss, wherein each member of the current limiter group has a function of limiting the current through its associated member of the electrode structure group to less than I when the electrode assembly is within the normal operating temperature range _tr And the resistance is in the positive directionAs a function of V, the short circuit resistance between one electrode structure and an adjacent counter electrode structure, the electrode structure resistance, the counter electrode structure resistance, the terminal resistance, and the number of electrode structure population members connected to the electrode buss within a normal operating temperature range.

Embodiment 115 the electrode assembly of any one of embodiments 1-54, further comprising at least one interface layer electrically connected between one or both of: a) A member of the electrode current collector and a member of the current limiter group, and b) a member of the current limiter group and the electrode buss.

Embodiment 116. The electrode assembly of embodiment 115, wherein the interfacial layer comprises a conductive coating.

Embodiment 117 the electrode assembly of embodiment 116, wherein the conductive coating comprises a coating of carbon nanotubes.

Embodiment 118. The electrode assembly of embodiment 116, wherein the conductive coating comprises a carbon-based coating.

Embodiment 119 the electrode assembly of any one of embodiments 116-118, wherein the conductive coating is coated on one or both of the member of the electrode current collector and the electrode buss.

Embodiment 120 the secondary battery of any one of embodiments 55-98, further comprising at least one interface layer electrically connected between one or both of: a) A member of the electrode current collector and a member of the current limiter group, and b) a member of the current limiter group and the electrode buss.

Embodiment 121. The secondary battery of embodiment 120, wherein the interfacial layer comprises a conductive coating.

Embodiment 122. The secondary battery of embodiment 121 wherein the conductive coating comprises a coating of carbon nanotubes.

Embodiment 123 the secondary battery of embodiment 122 wherein the conductive coating comprises a carbon-based coating.

Embodiment 124 the secondary battery of any one of embodiments 121-123, wherein the conductive coating is coated on one or both of the member of the electrode current collector and the electrode buss.

Embodiment 125. A method of assembling an electrode assembly, the method comprising: stacking a group of unit battery cells on top of each other in a stacking direction, each member of the group of unit battery cells comprising an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure comprises an electrode current collector and an electrode active material layer, the counter electrode structure comprises a counter electrode current collector and a counter electrode active material layer, the electrode structure and the counter electrode structure extend in a longitudinal direction perpendicular to the stacking direction, and an end portion of the electrode current collector extends beyond the electrode active material and the separator structure in the longitudinal direction; bending the end portion of each electrode collector in a direction orthogonal to the longitudinal direction of the electrode structure and extending in the stacking direction or in a direction opposite to the stacking direction; positioning an electrode buss extending in the stacking direction, wherein a surface of the electrode buss is adjacent to the end portion of the electrode current collector; and applying heat and pressure to the electrode buss to adhere the end portion of the electrode current collector to the buss by an adhesive layer comprising a resistive polymer material.

Embodiment 126. The method of embodiment 125 wherein the resistive polymer layer comprises a thermoplastic material.

Embodiment 127 the method of embodiment 125 wherein the adhesive layer is formed on the surface of the electrode buss that is in contact with the end portion of the electrode current collector.

Embodiment 128 the method of embodiment 127, wherein the resistive polymer material comprises an adhesive polymer and the adhesive layer comprises a conductive material suspended in the adhesive polymer.

Embodiment 129 the method of embodiment 128, wherein the conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

Embodiment 130. The method of embodiment 128 wherein the conductive material comprises metal coated carbon fibers.

Embodiment 131. The method of embodiment 130 wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

Embodiment 132. The method of embodiment 130, wherein the metal-coated carbon fiber has a length and a diameter, and an aspect ratio of the length to the diameter of the metal-coated carbon fiber is between 10:1 and 10,000:1, inclusive.

Embodiment 133. The method of embodiment 132, wherein the aspect ratio is between 50:1 and 5,000:1, inclusive.

Embodiment 134. The method of embodiment 132, wherein the aspect ratio is between 100:1 and 2,000:1, inclusive.

Embodiment 135. The method of embodiment 128, wherein the conductive adhesive has a melt flow index of between 0.1 grams (g)/10 minutes (min) to 1000g/10min as determined according to astm d 1238 at 190 ℃.

Embodiment 136. The method of embodiment 135 wherein the melt flow index is between 0.1g/10min and 100g/10 min.

Embodiment 137 the method of embodiment 135 wherein the melt flow index is between 0.5g/10min and 20g/10 min.

Embodiment 138 the method of embodiment 128, wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

Embodiment 139. The method of embodiment 138 wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

Embodiment 140. The method of embodiment 138, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.

Embodiment 141. The method of embodiment 125, wherein bending the end portion of each electrode current collector comprises: the electrode bus bar is positioned against the unbent end portion of each electrode collector, and pressure is applied toward the electrode collector and in the stacking direction.

Embodiment 142. The method of embodiment 125, wherein an end portion of each counter electrode current collector extends beyond the counter electrode active material and the separator structure in the longitudinal direction opposite the end portion of the electrode current collector, the method further comprising: bending the end portion of each counter electrode current collector to be substantially perpendicular to the longitudinal direction of the counter electrode structure and extend in the stacking direction or in a direction opposite to the stacking direction; positioning a counter electrode bus bar to extend in the stacking direction, wherein a surface of the counter electrode bus bar is in contact with the end portion of the counter electrode current collector; and attaching the counter electrode bus bar to the end portion of the counter electrode current collector.

Embodiment 143 the method of embodiment 142, wherein attaching the counter electrode buss to the end portion of the counter electrode current collector comprises gluing the counter electrode buss to the end portion of the counter electrode current collector.

Embodiment 144 the method of embodiment 142 wherein attaching the counter electrode buss to the end portion of the counter electrode current collector comprises attaching the counter electrode buss to the end portion of the counter electrode current collector by welding or brazing.

Embodiment 145 the method of embodiment 142 wherein the surface of the counter electrode buss that is in contact with the end portion of the counter electrode current collector has a resistive polymer layer disposed on the surface, and attaching the counter electrode buss to the end portion of the counter electrode current collector comprises applying heat and pressure to the counter electrode buss to adhere the end portion of the counter electrode current collector to the buss through the resistive polymer layer.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The scope of the patent of the invention is defined by the claims and may contain other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A method of assembling an electrode assembly, the method comprising:

stacking a group of unit battery cells on top of each other in a stacking direction, each member of the group of unit battery cells comprising an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure comprises an electrode current collector and an electrode active material layer, the counter electrode structure comprises a counter electrode current collector and a counter electrode active material layer, the electrode structure and the counter electrode structure extend in a longitudinal direction perpendicular to the stacking direction, and an end portion of the electrode current collector extends beyond the electrode active material and the separator structure in the longitudinal direction;

bending the end portion of each electrode collector in a direction orthogonal to the longitudinal direction of the electrode structure and extending in the stacking direction or in a direction opposite to the stacking direction;

positioning an electrode buss extending in the stacking direction, wherein a surface of the electrode buss is adjacent to the end portion of the electrode current collector; and

heat and pressure are applied to the electrode buss to adhere the end portion of the electrode current collector to the buss by an adhesive layer comprising a resistive polymer material.

2. The method of claim 1, wherein the electrically resistive polymer material comprises a thermoplastic material.

3. The method according to claim 1, wherein the adhesive layer is formed on the surface of the electrode bus bar that is in contact with the end portion of the electrode current collector.

4. The method of claim 1, wherein the resistive polymer material comprises an adhesive polymer and the adhesive layer comprises a conductive material suspended in the adhesive polymer.

5. The method of claim 4, wherein the conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

6. The method of claim 4, wherein the conductive material comprises metal coated carbon fibers.

7. The method of claim 6, wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

8. The method of claim 6, wherein the metal-coated carbon fiber has a length and a diameter, and an aspect ratio of the length to the diameter of the metal-coated carbon fiber is between 10:1 and 10,000:1, inclusive.

9. The method of claim 8, wherein the aspect ratio is between 50:1 and 5,000:1, inclusive.

10. The method of claim 8, wherein the aspect ratio is between 100:1 and 2,000:1, inclusive.

11. The method of claim 4, wherein the conductive adhesive has a melt flow index of between 0.1 grams (g)/10 minutes (min) and 1000g/10min, as determined according to astm d 1238 at 190 ℃.

12. The method of claim 11, wherein the melt flow index is between 0.1g/10min and 100g/10 min.

13. The method of claim 11, wherein the melt flow index is between 0.5g/10min and 20g/10 min.

14. The method of claim 4, wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

15. The method of claim 14, wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

16. The method of claim 14, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.

17. The method of claim 1, wherein bending the end portion of each electrode current collector comprises: the electrode bus bar is positioned against the unbent end portion of each electrode collector, and pressure is applied toward the electrode collector and in the stacking direction.

18. The method of claim 1, wherein an end portion of each counter electrode current collector extends beyond the counter electrode active material and the separator structure in the longitudinal direction opposite the end portion of the electrode current collector, the method further comprising:

bending the end portion of each counter electrode current collector to be substantially perpendicular to the longitudinal direction of the counter electrode structure and extend in the stacking direction or in a direction opposite to the stacking direction;

positioning a counter electrode bus bar to extend in the stacking direction, wherein a surface of the counter electrode bus bar is in contact with the end portion of the counter electrode current collector; and

the counter electrode bus bar is attached to the end portion of the counter electrode current collector.

19. The method of claim 18, wherein attaching the counter electrode buss to the end portion of the counter electrode current collector comprises gluing the counter electrode buss to the end portion of the counter electrode current collector.

20. The method of claim 18, wherein attaching the counter electrode buss to the end portion of the counter electrode current collector comprises attaching the counter electrode buss to the end portion of the counter electrode current collector by welding or brazing.

21. The method of claim 18, wherein the surface of the counter electrode buss that is in contact with the end portion of the counter electrode current collector has a resistive polymer layer disposed on the surface, and attaching the counter electrode buss to the end portion of the counter electrode current collector comprises applying heat and pressure to the counter electrode buss to adhere the end portion of the counter electrode current collector to the buss through the resistive polymer layer.

22. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a group of unit cells, a group of current limiters, an electrode buss, and a counter electrode buss, wherein

Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer,

for each member of the group of unit battery cells, (a) the electrode collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) a member of the group of current limiters is located in the electrical connection between (i) the electrode collector and the electrode bus bar or (ii) the counter electrode collector and the counter electrode bus bar,

Each member of the current limiter group includes a conductive adhesive having a resistance at 25 degrees celsius (°c) of greater than or equal to 0.25 ohms (Ω).

23. The electrode assembly of claim 22, wherein one or more of the following holds:

(a) The electrode structures are divided into groups of electrode structures, and the electrode structures in each group are electrically connected in parallel with each other, and each group of electrode structures is electrically connected to the electrode bus by a single member of the current limiter group, an

(b) The counter electrode structures are divided into groups of counter electrode structures, and the counter electrode structures in each group are electrically connected in parallel to each other, and each group of counter electrode structures is electrically connected to the counter electrode bus bar by a single member of the current limiter group.

24. The electrode assembly of claim 22, wherein the conductive adhesive comprises an adhesive polymer.

25. The electrode assembly of claim 24, wherein the conductive adhesive comprises a single layer of conductive adhesive, and each member of the current limiter population comprises a different portion of the single layer of conductive adhesive.

26. The electrode assembly of claim 25, wherein the single layer of conductive adhesive is disposed on the electrode buss or the counter electrode buss.

27. The electrode assembly of claim 24, wherein the conductive adhesive of each member of the current limiter group is physically separate from the conductive adhesive of each other member of the current limiter group.

28. The electrode assembly of claim 24, wherein the resistivity of the conductive adhesive is greater than or equal to 0.01 Ω -cm.

29. The electrode assembly of claim 24, wherein the conductive adhesive comprises one of functionalized polyethylene and functionalized polypropylene.

30. The electrode assembly of claim 24, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

31. The electrode assembly of claim 30, wherein the conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

32. The electrode assembly of claim 30, wherein the conductive material comprises metal coated carbon fibers.

33. The electrode assembly of claim 32, wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

34. The electrode assembly of claim 32, wherein the metal-coated carbon fibers have a length and a diameter, and an aspect ratio of the length to the diameter of the metal-coated carbon fibers is between 10:1 and 10,000:1, inclusive.

35. The electrode assembly of claim 34, wherein the aspect ratio is between 50:1 and 5,000:1, inclusive.

36. The electrode assembly of claim 34, wherein the aspect ratio is between 100:1 and 2,000:1, inclusive.

37. The electrode assembly of claim 30, wherein the conductive adhesive has a melt flow index of between 0.1 grams (g)/10 minutes (min) to 1000g/10min, determined according to astm d 1238 at 190 ℃.

38. The electrode assembly of claim 37, wherein the melt flow index is between 0.1g/10min to 100g/10 min.

39. The electrode assembly of claim 37, wherein the melt flow index is between 0.5g/10min to 20g/10 min.

40. The electrode assembly of claim 30, wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

41. The electrode assembly of claim 40, wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

42. The electrode assembly of claim 40, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.

43. An electrode assembly for cycling between a charged state and a discharged state over a normal operating temperature range between minus 20 degrees celsius (c) and 80 degrees celsius, the electrode assembly comprising a unit cell population, a current limiter population, an electrode bus, and a counter electrode bus, wherein

Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein

The electrode structure of each member of the unit cell group includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer,

for each member of the group of unit cells, (a) the electrode collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) at least one member of the group of current limiters is electrically connected between (i) the electrode collector and the electrode bus bar or (ii) the counter electrode collector and the counter electrode bus bar, and

for each unit cell, the at least one member of the current limiter group has a resistance when the electrode assembly is within the normal operating temperature range sufficient to limit current through the unit cell to less than a threshold current I that is less than a current that would induce thermal runaway of the unit cell.

44. The electrode assembly of claim 43, wherein one or more of the following holds:

45. The electrode assembly of claim 43, wherein the threshold current I is greater than or equal to 8 amps and less than or equal to 12 amps.

46. The electrode assembly of claim 43, wherein the current limiter population comprises a conductive adhesive.

47. The electrode assembly of claim 46, wherein the conductive adhesive comprises a single layer of conductive adhesive, and each member of the current limiter population comprises a different portion of the single layer of conductive adhesive.

48. The electrode assembly of claim 47, wherein the single layer of conductive adhesive is disposed on the electrode buss or the counter electrode buss.

49. The electrode assembly of claim 46, wherein the conductive adhesive of each member of the current limiter group is physically separate from the conductive adhesive of each other member of the current limiter group.

50. The electrode assembly of claim 46, wherein the conductive adhesive comprises one of functionalized polyethylene and functionalized polypropylene.

51. The electrode assembly of claim 46, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

52. The electrode assembly of claim 51, wherein the conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

53. The electrode assembly of claim 51, wherein the conductive material comprises metal coated carbon fibers.

54. The electrode assembly of claim 53, wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

55. The electrode assembly of claim 53, wherein the metal-coated carbon fibers have a length and a diameter, and an aspect ratio of the length to the diameter of the metal-coated carbon fibers is between 10:1 and 10,000:1, inclusive.

56. The electrode assembly of claim 56, wherein the aspect ratio is between 50:1 and 5,000:1, inclusive.

57. The electrode assembly of claim 56, wherein the aspect ratio is between 100:1 and 2,000:1, inclusive.

58. The electrode assembly of claim 51, wherein the conductive adhesive has a melt flow index of between 0.1 grams (g)/10 minutes (min) to 1000g/10min as determined according to astm d 1238 at 190 ℃.

59. The electrode assembly of claim 59, wherein the melt flow index is between 0.1g/10min to 100g/10 min.

60. The electrode assembly of claim 59, wherein the melt flow index is between 0.5g/10min to 20g/10 min.

61. The electrode assembly of claim 51, wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

62. The electrode assembly of claim 62, wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

63. The electrode assembly of claim 62, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.

64. An electrode assembly for cycling between a charged state and a discharged state, the electrode assembly comprising a group of unit cells, an electrode buss, a counter electrode buss, and a current limiter group, wherein

Each member of the unit cell group includes an electrode structure, a separator structure, and a counter electrode structure, wherein the electrode structure of each member of the unit cell group has a capacity C and includes an electrode current collector and an electrode active material layer, and the counter electrode structure of each member of the unit cell group includes a counter electrode current collector and a counter electrode active material layer,

for each member of the group of unit battery cells, (a) the electrode collector of the electrode structure is electrically connected to the electrode bus bar, (b) the counter electrode collector of the counter electrode structure is electrically connected to the counter electrode bus bar, and (c) members of the group of current limiters are electrically connected between (i) the electrode collector and the electrode bus bar or (ii) the counter electrode collector and the counter electrode bus bar,

each member of the unit cell group has a maximum charge voltage V between the electrode collector and the counter electrode collector _TOC And has a unit cell resistance R determined at a non-zero frequency between the electrode collector and the counter electrode collector _bl And (2) and

each member of the current limiter group has a resistance R _cld The resistance limits the amount of current that can be conducted from the electrode or the counter electrode buss to a member of a group of unit cells during discharge of the electrode assembly in which there is an electrical short between the electrode and the counter electrode of one member of the group of unit cells to a value I determined according to the following equation:

wherein R is _S Hard short resistance as determined using a dry Forced Internal Short (FISC) test, R, which is a member of a unit cell group _t Is the combined resistance of the electrode bus and the counter electrode bus determined at the non-zero frequency, and R _cld Having a non-zero value such that:

I _c *R _cld <0.5 volt

Wherein I is _c Is the 1C current rate.

65. The electrode assembly of claim 65, wherein I is less than I _L And I _L Is the current that will induce thermal runaway of a member of the unit cell group by that member of the unit cell group, and is determined by an iterative wet FISC test.

66. The electrode assembly of claim 65, wherein one or more of the following holds:

67. The electrode assembly of claim 65, wherein I is greater than or equal to 8 amps and less than or equal to 12 amps, and V _TOC 4.35 volts.

68. The electrode assembly of claim 65, wherein and R _cld Having a non-zero value such that:

I _c *R _cld <0.02 volts.

69. The electrode assembly of claim 65, wherein the current limiter population comprises a conductive adhesive.

70. The electrode assembly of claim 70 wherein the conductive adhesive comprises a single layer of conductive adhesive and each member of the current limiter population comprises a different portion of the single layer of conductive adhesive.

71. The electrode assembly of claim 71, wherein the single layer of conductive adhesive is disposed on the electrode buss or the counter electrode buss.

72. The electrode assembly of claim 70, wherein the conductive adhesive comprises an adhesive polymer having a conductive material suspended therein.

73. The electrode assembly of claim 73, wherein the conductive material comprises one or more of: carbon black, nickel, copper, gold, silver, titanium, graphite, molybdenum, chromium, and aluminum.

74. The electrode assembly of claim 73 wherein said conductive material comprises metal coated carbon fibers.

75. The electrode assembly of claim 75, wherein the metal-coated carbon fibers comprise nickel-coated carbon fibers.

76. The electrode assembly of claim 75, wherein the metal-coated carbon fibers have a length and a diameter, and an aspect ratio of the length to the diameter of the metal-coated carbon fibers is between 10:1 and 10,000:1, inclusive.

77. The electrode assembly of claim 77, wherein said aspect ratio is between 50:1 and 5,000:1, inclusive.

78. The electrode assembly of claim 77, wherein said aspect ratio is between 100:1 and 2,000:1, inclusive.

79. The electrode assembly of claim 73, wherein the conductive adhesive has a melt flow index of between 0.1 grams (g)/10 minutes (min) to 1000g/10min as determined according to astm d 1238 at 190 ℃.

80. The electrode assembly of claim 80, wherein said melt flow index is between 0.1g/10min to 100g/10 min.

81. The electrode assembly of claim 80, wherein said melt flow index is between 0.5g/10min to 20g/10 min.

82. The electrode assembly of claim 73 wherein the conductive adhesive has a melting point between 40 ℃ and 300 ℃.

83. The electrode assembly of claim 83, wherein the melting point of the conductive adhesive is between 60 ℃ and 200 ℃.

84. The electrode assembly of claim 83, wherein the melting point of the conductive adhesive is between 70 ℃ and 165 ℃.