JP2021529414A - Rechargeable lithium-ion battery with anode structure including porous region - Google Patents

Abstract

A rechargeable lithium ion battery having a high capacity is provided. The lithium ion battery has a single configuration and includes an anode structure that includes a non-porous region and a porous region, which is a top porous layer having a first thickness and a first porosity. It includes (porous region 1) and a bottom porous layer (porous region 2) that is located below the top porous layer and forms an interface with the non-porous region. At least the upper portion of the non-porous region and the entire porous region are made of silicon, and the bottom porous layer has a second thickness greater than the first thickness and greater than the first porosity. It has a second porosity.

Description

This application relates to rechargeable batteries. More specifically, the present application comprises an anode structure composed of a substrate comprising a porous semiconductor region having two different porosities and a non-porous semiconductor region located below the porous semiconductor region. Regarding capacity rechargeable lithium-ion batteries.

In recent years, for example, computers, cell phones, tracking systems, scanners, medical devices, smart watches, power tools, remote systems and sensors, electric vehicles, Internet of Things (IOT), and fitness devices. The demand for electronic devices such as is increasing. One of the drawbacks of these electronic devices is that they need to include a power source within the device itself. Usually, a battery is used as a power source for such an electronic device. The battery must have sufficient capacity to power the electronic device at least while the device is in use. Sufficient battery capacity can result in a power source that is significantly heavier, / or larger than the rest of the electronic device. Therefore, a smaller and lighter power source with sufficient energy storage is desired. Such a power source can be realized in combination with a smaller and lighter electronic device and a lithium ion material acting as a charge carrier. Lithium-ion batteries and capacitors are considered to be optimal for smaller, more energy-dense energy storage devices, as lithium is the lightest and most electrically positive charge carrier ion in the Periodic Table of the Elements.

In addition to the demand for lightweight energy storage devices that provide high energy density (high capacity), the demand for faster charging speeds (ie, faster charging kinetics) is also a current demand in the consumer market. For next-generation batteries, it would be desirable if the batteries could be fully charged within 10 minutes to meet consumer demands in markets such as electric vehicles, portable telecommunications, IOT, and sensors. In the case of electric vehicles, if the consumer has to wait longer than 10 minutes to charge his / her vehicle, the battery-powered electric vehicle will limit the user's schedule and, as a result, their range of travel. May be added. Therefore, the use of fast charging speed batteries in the electric vehicle market will help create a feasible electric vehicle market that will compete with and perhaps replace gasoline-powered vehicles.

Another drawback of traditional batteries is that some batteries contain potentially flammable and toxic materials that can leak, resulting in safety hazards and costly product recalls. There is. As a result, these batteries are subject to government regulation and can damage the product's reputation. The risk of battery leakage can be increased by the formation of cracks in these batteries. These cracks are probably caused by internal stresses from the battery charge / discharge cycle.

In addition, in the case of batteries containing solid electrolytes, it has been demonstrated that the formation of dendrites in these batteries reduces battery life performance. The size of the dendrite increases over the life of the battery and is probably related to the number of charge / discharge cycles of the battery. When dendrites are formed in the battery and grow large over time, the dendrites are prone to electrical shorting of the internal components of the battery, leading to battery failure.

Sustainable all-solid or semi-solid lithium-ion batteries with the advent of lithium metal charging host electrodes that provide a stable charging host for lithium metals and promote reversible ionization mechanisms from lithium ions to lithium metals and vice versa. Mass production in the consumer market can be achieved. Lithium metal maintains a theoretical energy capacity of 3850 mAh / g, whereas silicon-based lithium host electrode materials maintain a theoretical capacity of 4200 mA / g. For example, both of these materials acting as anodes are greater than 10 times the theoretical capacity (372 mAh / g) of conventional graphite anode materials. However, these batteries still carry the risk of cracking, leaking, and internal dendrite failure.

Thus, it has reduced charge time, higher storage capacity, can be safely recharged over multiple charge / discharge life cycles, and is susceptible to cracking, leakage, and dendrite growth in the battery. There is a need for improved lithium-ion batteries to provide power supply with reduced risk.

A rechargeable lithium-ion battery that maintains a high capacity (ie, a capacity of 100 mAh / g or more) is provided. In some embodiments, the rechargeable lithium-ion batteries of the present application have increased life, increased number of charge / discharge cycles, reduced charging time (ie fast charging speed), volume expansion or deformation during the cycle or the like thereof. Reduction of both, reduction of dendrite and crack formation, reduction of battery leakage due to cracking, or a combination thereof can also be shown.

The rechargeable lithium-ion battery of the present application includes an electrolyte region located between the lithium-containing cathode material layer and the anode structure. The anode structure is a single structure (ie, a monolithic structure) and includes a non-porous region and a porous region. The porous region is larger than the top porous layer (porous region 1) having a first thickness and a first porosity and a second porosity and a first thickness greater than the first porosity. Includes a bottom porous layer (porous region 2) with a large second thickness. The bottom porous layer (ie, porous region 2) is located below the top porous layer (ie, porous region 1) and forms an interface with the non-porous region. In addition, at least the upper portion of the non-porous region and the entire porous region are made of silicon.

In another aspect of the application, there is provided a method of making the aforementioned anode structure for a rechargeable lithium ion battery. The method comprises the step of anode etching a substrate containing at least the upper region composed of p-doped silicon. In one embodiment, the relative depth, pore structure, and surface area of the anode structure, including the porous regions 1 and 2, are controlled through the applicable conditions of the methods of the present application.

Another aspect of the application shows a change in behavior with respect to the anode structure for a rechargeable battery during a battery charge and discharge cycle. The anode structure and battery structure of the present application are charged in a unique manner that exhibits reduced internal stress and reduced dendrite growth over battery life. Although not desired to be tied to any theory, the charging operation of the present application is believed to contribute to reducing the level of internal battery stress and reducing the occurrence of cracks in the anode structure.

In yet another aspect of the application, a combination of the present anode structure with a cathode material comprising a particular particle size and particle boundary density or columnar ultrastructure is used. The anode structure of the present application is capable of sustainably plating lithium materials supplied from the respective cathode materials of various dimensions and masses. In particular, since the anode structure of the present application promotes apparent lithium plating during charging and lithium peeling during discharging, a high-capacity battery cell can be easily manufactured.

It is sectional drawing which shows the exemplary rechargeable lithium ion battery by 1st Embodiment of this application. FIG. 5 is a cross-sectional view showing another exemplary rechargeable lithium-ion battery according to a second embodiment of the present application. FIG. 5 is a cross-sectional view showing an exemplary rechargeable lithium-ion battery according to a third embodiment of the present application. FIG. 5 is a cross-sectional view showing an exemplary rechargeable lithium-ion battery according to a fourth embodiment of the present application. FIG. 5 is a cross-sectional view showing an exemplary rechargeable lithium-ion battery according to a fifth embodiment of the present application. FIG. 5 is a cross-sectional view showing an exemplary rechargeable lithium-ion battery according to a sixth embodiment of the present application. FIG. 5 is a cross-sectional view showing an exemplary rechargeable lithium-ion battery according to a sixth embodiment of the present application. It is the schematic which shows the method of forming the anode structure of this application starting from the p-type crystalline silicon substrate before anodizing, and the anode structure after anodizing. FIG. 3 is a transmission electron microscope (TEM) of a cross section showing a porous silicon anode structure representing two separate porous regions during anodic oxidation. (A) is a high resolution transmission electron microscope (HRTEM: high resolution transmission electron microscope) of a porous silicon anode structure showing the thickness of the porous region 1. (B) is a secondary ion mass spectrometry of the first about 30 nm of the porous silicon anode structure corresponding to the porous region 1 and the first about 90 nm of the same silicon anode structure corresponding to the porous region 2. SIMS: secondary ion mass spectrometry) It is a figure which shows the spectrum. (A) is a diagram showing a part of a flow chart showing an anode structure before operational use. (B) is a diagram showing a part of a flow chart showing an anode structure during operational use, in which a seed layer is formed during a charging cycle. (C) is a diagram showing a part of a flow chart showing an anode structure during operational use, in which lithium plating occurs after continuous charging. It is a figure which shows the SEM image of the porous silicon anode structure after 5 cycles when a liquid electrolyte was used. (A) is a diagram showing a part of a flow chart showing an anode structure during operational use, in which lithium peeling occurs during discharge. (B) is a diagram showing another SEM image of the porous silicon anode structure after about 250 cycles when using a liquid electrolyte. FIG. 10A shows an SEM image of an all-solid-state lithium-ion battery according to the present application containing a structure similar to that shown in FIG. 1 where the electrolyte region is a solid material, FIG. 10A is before charging or discharging with constant current or constant potential induction. It is an SEM showing the structure of. FIG. 10B shows an SEM image of an all-solid-state lithium-ion battery according to the present application containing a structure similar to that shown in FIG. 1 where the electrolyte region is a solid material, FIG. 10B shows the structure after the charge and discharge cycle of 6. Another SEM. FIG. 10C shows an SEM image of an all-solid-state lithium-ion battery according to the present application containing a structure similar to that shown in FIG. 1 where the electrolyte region is a solid material, FIG. 10C shows the structure after 67 charge and discharge cycles. Yet another SEM image. It is a flow chart which shows one Embodiment for making the anode structure of this application.

The application will now be described in more detail with reference to the following considerations and drawings that accompany the application. The drawings of this application are provided for illustrative purposes only and are not drawn to scale. In addition, note that similar and corresponding components are indicated by similar reference numbers.

In the following description, a number of specific details such as specific structures, components, materials, dimensions, processing steps, and techniques are provided to provide an understanding of the various embodiments of the present application. There is. However, given this disclosure, one of ordinary skill in the art will recognize that there are various alternative embodiments of the application that can be implemented without providing further specific details. In other cases, well-known structures or processing steps may be used in combination with or with the concepts of the invention. To avoid obscuring the application, these structures and steps are not described in detail.

When a component as a layer, region, or substrate is said to be "on" or "over" of another component, that component is directly above the other component. It will be understood that there may be intervening components as well. On the other hand, when one component is said to be "directly on" or "directly over" another component, there are no intervening components. In addition, when one component is said to be "beneath" or "under" of another component, that component is said to be below or under the other component. It will be understood that it may be present directly in or there may be intervening components. On the other hand, when one component is said to be "directly beneath" or "directly under" another component, there are no intervening components.

As described above, a rechargeable lithium ion battery having a high capacity (that is, a capacity of 100 mAh / g or more) is provided. In some embodiments, the rechargeable lithium-ion batteries of the present application also exhibit increased life, faster charging rates, and / or reduced volume expansion and / or deformation during charge / discharge cycles, or a combination thereof. You may. The rechargeable lithium-ion battery of the present application has an anode structure designed to increase the capacity and possibly the charging speed of the battery (compared to the conventional lithium-ion battery which does not have the anode structure of the present application). include.

In one aspect of the application, a rechargeable lithium ion battery comprising a single anodic structure is provided. In particular, the anode structure comprises a non-porous region and a porous region, the porous region having a top porous layer (porous region 1) having a first thickness and a first porosity, and a first thickness. Includes a bottom porous layer (porous region 2) having a second thickness greater than that and a second porosity greater than the first porosity. The bottom porous layer (porous region 2) is located below the top porous layer (porous region 1) and forms an interface with the non-porous region. In the anode structure of the present application, at least the upper portion of the non-porous region and the entire porous region (including the porous regions 1 and 2) are composed of silicon.

A method of making a battery, a method of using the battery, structural features of the battery in use, and a battery structure with a cathode that allows for high charging speeds are also provided. The anode structure of the present application can be used as a component in various conventional 2D and 3D battery configurations.

Since the porous region 1 contains an average smaller pore size than the porous region 2, the anode structure of the present application is considered to be stronger than that of the prior art. In some embodiments, the anode structure containing the larger non-porous region along with the porous region 1 and the porous region 2 is made of the same mechanically, electrically, and chemically the same semiconductor material (ie, the anode). The structure is a monolithic structure). Thus, a mechanically stronger anode structure that is totally interconnected at the atomic level is provided, especially for silicon substrates of crystalline composition.

In addition, it is believed that upon initial lithiolysis of the anode structure of the present application, the upper portion of the porous region 2 is partially lithium-containing and the lower portion of the porous region 2 is substantially lacking lithium. .. During this process, a thin seed layer begins to form, which is composed of a lithium-rich material and a silicon material, resulting in a planar lithium metal dense layer at the top of the porous region 1. Will be done. This seed layer significantly reduces the migration of lithium ions deeper into the porous region 2 of the anode structure (and reduces the concentration of lithium ions in the porous region 2). Thus, the formation of a thin seed layer above / in the porous region 1 prevents further lithiolysis of the porous region 2, resulting in a deeper depth of the porous region 2 and the non-porous region 2. Further suppression of lithiolysis minimizes the mechanical stress of the entire electrode.

When lithium moves into the anode structure, the volumetric region where lithium and the silicon of the anode structure combine expands. This volume can expand up to 400 percent of the original anode structure volume. Thus, the anode structure of the present application allows for reduced volume expansion during the life of the rechargeable lithium-ion battery (entire charge / discharge cycle), resulting in a reduction in internal stress throughout the use of the battery.

Since lithium binds to the silicon in the porous regions 1 and 2, the space within these porous regions adapts to the increase in volume in these parts of the anode structure, further reducing the mechanical stresses of charging and discharging.

In addition, lithium maintains a seed layer of lithium combined with silicon atoms present in the porous region of the anode structure as the battery charges / discharges over the entire battery life. This seed layer may be hereinafter referred to as a lithium-containing seed layer. During seed layer formation, a small portion of lithium (less than 10% of theoretical volume) enters and penetrates the porous region 1 and partially penetrates the porous region 2. This process is relatively slow when not electrochemically induced, and faster when induced at a constant current or potential. Since lithium accumulates on / in the previously deposited lithium-containing seed layer in the porous region 1, lithium further forms a thin layer of metallic lithium on top of the porous region 1 and the porous region 1 The volume inside is expanded to physically close the pores in the porous region 1, and the lithium concentration of the seed and metal layers provides an electrostatic barrier against further entry of lithium into the anode structure of the present application. This minimizes the further migration of lithium deeper into the anode structure of the present application.

The fully formed seed layer minimizes the further transfer of lithium to the anode structure during subsequent charge / discharge cycles of the battery, thus allowing volume expansion and contraction during the charge / discharge cycle for most of the battery life. Reduces the periodic mechanical stress of the anode structure and thereby reduces the stress of the anode structure over the life of the battery.

The fully formed seed layer impedes the transfer of lithium ions to the anode structure, so the following is observed: (I) Lithium ions moving from the cathode and electrolyte regions of the battery towards the anode structure during the charge cycle increase the thickness of the lithium metal layer above the seed layer, and (ii) the battery during the discharge cycle. Lithium ions moving away from the anode structure from the cathode and electrolyte regions of the battery reduce the thickness of the lithium metal layer above the seed layer. However, contrary to the prior art, the fully formed seed layer minimizes lithium diffusion during subsequent charge / discharge cycles of the battery. As a result of the anode structure of the present application, lithium is deposited mainly on the seed layer (eg via ion plating) and the amount within the porous region 2 is significantly reduced, but the non-porous region of the anode structure. No significant amount is found inside. As a result, the very large volume of the anode structure, i.e. the non-porous region of the anode structure, does not substantially absorb lithium during the charge / discharge cycle and is therefore observed in batteries that do not contain the anode structure of the present application. Does not cause significant volume expansion and contraction resulting in cracking and possible leakage.

It is speculated that the thin seed layer once formed does not change significantly during the battery charge / discharge cycle. The porosity of the porous region 1 is selected so that the volume expansion of the top porous layer of the anode structure due to chemical bonding with lithium during seed layer formation does not cause excessive stress in the porous region 1.

The seed layer forms a smooth, planar surface on which the thickness of the metallic lithium metal layer increases (reduces) by adding (and removing) lithium ions during the charge (discharge) cycle of operation. Applicants have experimental evidence that a relatively smooth, planar surface is maintained over the life of the battery, increasing the likelihood of suppression of dendrite growth.

Here, with reference to FIG. 1, an exemplary rechargeable lithium-ion battery according to a first embodiment of the present application is shown. An exemplary rechargeable lithium-ion battery shown in FIG. 1 includes a battery material stack of an anode current collector 10, an anode structure 12, an electrolyte region 18, a lithium-containing cathode material layer 20, and a cathode current collector 22. .. Although the present application shows the anode current collector 10 as the bottom material layer of the lithium ion battery, the present application also has an embodiment in which the cathode current collector 22 represents the bottom material layer of the lithium ion battery of the present application. I'm assuming. Other orientations for lithium-ion batteries are also possible and are not excluded from this application.

In some embodiments, the rechargeable lithium-ion battery of the present application may be formed on a base substrate (not shown). When present, the base substrate may contain any conventional material used as a substrate for a lithium ion battery. In one embodiment, the base substrate may include a silicon-containing material and / or any other material having semiconductor properties. The term "silicon-containing material" is used throughout this application to refer to a material that contains silicon and has semiconducting properties. Examples of silicon-containing materials that can be used as base substrates for rechargeable lithium-ion batteries include silicon (Si), silicon-germanium alloys (SiGe), or carbon-doped silicon-based alloys. In one embodiment, the base substrate for a rechargeable lithium-ion battery is a bulk semiconductor substrate. By "bulk" is meant that the base substrate is entirely composed of at least one semiconductor material. In one example, the base substrate may be entirely composed of silicon, which may be single crystal. In some embodiments, the bulk semiconductor substrate may include a multilayer semiconductor material stack containing at least two different semiconductor materials. In one example, the multilayer semiconductor material stack may include stacks of Si and silicon germanium alloys in any order. In another embodiment, the multilayer semiconductor material may include a stack of Si and one or more silicon-based alloys, such as silicon germanium or carbon-doped silicon-based alloys, in any order.

In other embodiments, the base substrate for a lithium ion battery is, for example, aluminum (Al), aluminum alloy, titanium (Ti), tantalum (Ta), tungsten (W), or molybdenum (Mo), copper (Cu), nickel. It may be a current collector such as (Ni), platinum (Pt), or any alloy of these materials.

In some embodiments, the base substrate may have a non-textured (flat or flat) surface. The term "non-textured surface" refers to a surface that is smooth and has a surface roughness on the order of less than 100 nm root mean square when measured by shape measurement or atomic force microscopy. In yet another embodiment, the base substrate may have a textured surface. In these embodiments, the surface roughness of the textured substrate can range from 100 nm root mean square to 100 μm root mean square when also measured by shape measurement or atomic force microscopy. Textured etches a non-textured substrate by forming multiple etching masks (eg, metal, insulator, or polymer) on the surface of the non-textured substrate and using the multiple masks as etching masks. It can be done by removing the etching mask from the untextured surface of the substrate. In some embodiments, the textured surface of the base substrate is composed of a plurality of high surface area 3D features. In some embodiments, multiple metal masks are used, and these metal masks may be formed by depositing layers of metal material and then annealing. Dewetting of the surface of the base substrate occurs when the layer of metal material melts and balls up during annealing.

Returning to the reference of FIG. 1, the anode current collector 10 that can be used in this application is, for example, titanium (Ti), platinum (Pt), nickel (Ni), copper (Cu), aluminum (Al), or titanium nitride (Al). Includes any metal anode-side electrode material such as TiN). The anode collector 10 may include a layer of metal anode side electrode material or a material stack of at least two different metal anode side electrode materials. In one example, the anode current collector 10 includes a stack of nickel (Ni) and copper (Cu) from bottom to top. The anode current collector 10 may have a thickness of 10 nm to 50 □ m. Other thicknesses that are less than or greater than the thickness values described above may also be used for the anode current collector 10. The anode current collector 10 includes, for example, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), evaporation, sputtering, plating, or deposition including mechanically adhered metal foil. It can be formed using a process. It would be preferable to alloy the metal anode side electrode material with the semiconductor material base to improve contact resistance. As is known in the semiconductor industry, alloying may be achieved by performing a siliconization process.

The anode structure 12 is provided on the surface of the anode current collector 10. The anode structure 12 includes a non-porous region 14 and a porous region (16, 17) having two layers with different porosities and thicknesses located above the non-porous region 14. The porous region of the anode structure includes a bottom porous layer 16 (ie, porous region 2) and a top porous layer 17 (ie, porous region 1). The non-porous region 14 and the porous region (16, 17) have a single configuration. In one embodiment, the non-porous region 14 has a first surface that is in direct physical contact with the surface of the porous region 2 (ie, the bottom porous layer 16) and an anode that is opposite the first surface. It has a second surface that is in direct physical contact with the current collector 10. The non-porous region 14 is the largest part of the volume of the anode structure 12. In some embodiments, the non-porous region 14 of the anode structure 12 may have a thickness of 5 μm to 700 μm.

The porous region 1 (ie, the top porous layer 17) has a first porosity and a first thickness, and the porous region 2 (ie, the bottom porous layer 16) has a second porosity and a second porosity. Has a thickness. Porous regions (16, 17) is designed. In one embodiment, the second porosity has an average porosity greater than 3 nm and the second thickness is 0.1 μm to 20 μm, whereas the first porosity is less than 3 nm. It has an average porosity of 50 nm or less and has a first thickness of 50 nm or less. Although not desired to be tied to any theory, it is believed that the inclusion of relatively small diameter pores in the porous region 1 facilitates the formation of a flattened lithium-containing seed layer (as described herein). It will be explained in detail below).

In this application, porosity can be a measure of the volume percentage of pores (spatial regions within silicon) divided by the total volume of porous regions (16, 17). Void ratios are, for example, SEM, RBS, X-ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR), Raman spectroscopy, gas adsorption on solids (porosistri), mercury space-filled porosometry, It may be measured using techniques well known to those skilled in the art, such as density function theory (DFT), or Brunauer-Emmett-Teller (BET).

It should be noted that the present application avoids the porosity (16, 17) having a porosity of 30% or more, which tends to be brittle and may crack during use as in the prior art, which may cause battery failure.

Although not desired to be tied to any theory, the porous regions (16, 17) are the porous region 1 (ie, top porous layer 17) and the lower degree of porous region 2 (ie, bottom porous layer 16). ) Sufficiently open space to accommodate expansion (ie, increase) and / or deformation of both volumes is presumed to have a porosity such that there is in the porous region (16, 17). This is particularly true in the formation of the lithium-containing seed layer described in more detail below herein in the porous region 1 (ie, the top porous layer 17) in the initial operation of the rechargeable lithium-ion battery.

The porous region 2 (ie, the bottom porous layer 16) of the anode structure 12 of the present application has a compressive stress of 0.02% to 0.035%. The compressive stress can be determined by X-ray diffraction or other optical or spectroscopic techniques.

As described above, the porous region 1 (that is, the top porous layer 17), the porous region 2 (that is, the bottom porous layer 16), and the non-porous region 14 of the anode structure 12 have a single configuration. Thus, the non-porous regions 14 and the porous regions (16, 17) are electrically, chemically, and mechanically part of the same anode structure. In some embodiments, the porous region 1 (ie, the top porous layer 17), the porous region 2 (bottom porous layer 16), and the non-porous region 14 are entirely composed of silicon. In this embodiment, the anode structure 12 is made by an efficient method step. In addition, in embodiments where the entire anode structure 12 is made of the same semiconductor material (ie Si), there is mechanical stress or additional electrical resistance within the anode structure 12 that can be brought about by the interfaces between the different materials. not exist. In one example, the anode structure 12 including the non-porous regions 14 and the porous regions (16, 17) has a three-dimensional (3D) lattice skeleton composed of a p-type crystalline silicon material. The term "p-type" refers to the addition of impurities to an intrinsic silicon material that results in a deficiency of valence electrons. Examples of p-type dopants, or impurities, in silicon-containing silicon materials include, but are not limited to, boron, aluminum, gallium, and indium.

In some embodiments, at least the upper portion of the non-porous region 14 of the anode structure 12 forming an interface with the porous region 2 (ie, the bottom porous layer 16) and the entire porous region (16, 17). Is composed of the same material, for example a p-type doped silicon material, whereas the lower portion of the non-porous region 14 forms an interface with the porous region 2 (ie, the bottom porous layer 16). The upper portion of the non-porous region 14 of the anode structure 12 and the entire porous region (16, 17) may be made of a different semiconductor material. For example, the lower portion of the non-porous region 14 existing beneath the porous regions (16, 17) has a dopant concentration different from the original p-type doped silicon used to provide the anode structure 12. It may contain doped silicon or a silicon-germanium alloy containing less than 10 atomic percent germanium.

In some embodiments, due to the simplicity and manufacturability of the single crystal material, at least above the non-porous region 14 of the anode structure 12 forming an interface with the porous region 2 (ie, the bottom porous layer 16). The silicon material that provides the portion and the entire porous region (16, 17) is a single crystal. In some embodiments, the cost of the process is reduced by using lower grade silicon and by adjusting the thickness of the silicon to simplify the crystal growth technique (as observed in the solar industry). Can be reduced and controlled.

The anode structure 12 of the present application can be formed using an anode etching process as defined in more detail below herein (see, eg, FIG. 11).

The electrolyte that may be present in the electrolyte region 18 may include any conventional electrolyte that can be used in rechargeable lithium-ion batteries. Electrolytes are liquid electrolytes, solid electrolytes, gel-type electrolytes, polymer electrolytes, semi-solid electrolytes, electrolytes that are originally liquid but are later conditioned to convert their phase to solid or semi-solid, or any combination thereof. For example, it may be a combination of a liquid electrolyte and a solid electrolyte. In some embodiments, the electrolyte region 18 is entirely composed of solid electrolyte. In other embodiments, the electrolyte region 18 may include a solid electrolyte and a liquid electrolyte. The electrolyte is between the porous region 1 (ie, the top porous layer 17) and the lithium-containing cathode material layer 20.

In some embodiments, the electrolyte region 18 is a solid electrolyte composed of a polymer-based material or an inorganic material. In another embodiment, the electrolyte region 18 is a solid electrolyte containing a material that allows the conduction of lithium ions. Such materials may be electrically insulating and ionic conductive. Examples of materials that can be used as solid electrolytes are lithium phosphate nitride (LiPON) or lithium phosphosilite acid nitride (LiSiPON), thio-LiSiCoN electrolytes (eg, any ratio of Li _{2 SP 2} S _5). ), Li ₁₀ SnP ₂ S ₁₂ , LiSiCoN-like electrolyte (eg, Li ₁₀ GeP ₂ S ₁₂ ), algyrodite electrolyte (eg, Li ₆ PS ₅ Br), garnet electrolyte (eg, Li _6.55 La ₃ Zr ₂ Ga _{0). .15} O ₁₂ ), NaSiCoN-like electrolyte (eg, Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ ), Li nitride electrolyte (eg, Li ₃ N), Li hydride electrolyte (eg, Li hydride) Includes, but is not limited to, Li ₂ NH), or perovskite electrolytes (eg, Li _0.34 La _0.51 TiO _2.94).

In the embodiment in which the liquid electrolyte is used in the electrolyte region 18, a separator (not shown) may be used. Separators may also be used in embodiments where two different electrolytes are present in the electrolyte region 18. When a separator is used, the separator is a flexible porous material, gel, or cellulose, cellophane, polyvinyl acetate (PVA), PVA / cellulose mixture, polyethylene (PE: polyethylene), polypropylene (PP: polypolylone). ), Or may contain one or more sheets composed of a mixture of PE and PP. In addition, the separator may be composed of inorganic insulating nano / micro particles.

In embodiments where a solid electrolyte layer is used as the electrolyte region 18, the solid electrolyte can be such as, for example, sputtering, solution deposition, hot pressing, cold pressing, controlled temperature and pressure conditions following slurry casting, or plating. It may be formed using a deposition process. In one embodiment, the solid electrolyte is formed by sputtering using any conventional target source material with a reactive or inert gas. For example, in the formation of the LiPON electrolyte, sputtering may be performed at least in the presence of a nitrogen-containing environment. In some embodiments, the nitrogen-containing environment is used as is, i.e. undiluted. In other embodiments, the nitrogen-containing environment can be diluted with an inert gas such as, for example, helium (He), neon (Ne), argon (Ar), and mixtures thereof. _{The nitrogen (N 2} ) content in the nitrogen-containing environment used is typically 10% to 100%, with a more typical nitrogen content of 50% to 100% in the environment.

The lithium-containing cathode material layer 20 may contain a lithium-containing material such as a lithium-based mixed oxide. Examples of lithium-based mixed oxides that can be used as the lithium-containing cathode material layer 20 are lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganese oxide (LiMn ₂ O ₄ ), lithium. Any combination of vanadium pentaoxide (LiV ₂ O ₅ ), lithium nickel manganese cobalt (NMC), nickel cobalt aluminum oxide (NCA), sulfur-based materials with lithium and other structural support elements such as iron, for example, Alternatively, it includes, but is not limited to, lithium iron phosphate (LiFePO _4). The lithium-containing cathode material layer 20 may have a thickness of 10 nm to 50 μm. Other thicknesses that are less than or greater than the thickness values described above may also be used for the lithium-containing cathode material layer 20.

In some embodiments, the lithium-containing cathode material layer 20 may be formed using a deposition process such as sputtering, slurry casting, or plating. In one embodiment, the lithium-containing cathode material layer 20 is formed by sputtering using any conventional precursor source material or a combination of multiple precursor source materials. In one example, a lithium precursor source material and a cobalt precursor source material are used in the formation of the lithium cobalt mixed oxide. Sputtering may be carried out in a mixture of the inert gas and oxygen. In these embodiments, the oxygen content of the inert gas / oxygen mixture may be from 0.1 to 70 percent percent, with the remainder of the mixture containing the inert gas. Examples of the inert gas that can be used with oxygen include argon, helium, neon, nitrogen, or any combination thereof.

In some embodiments, the lithium-containing cathode material layer 20 may be formed by slurry casting, which is electrochemically active [cathode material, electron conductive material (eg, carbon-based material)] and inert (eg, carbon-based material). It may contain a mixture of the components of the binder material). The thickness of these layers can range from 5 μm to 500 μm. These slurries may also have electrolyte components in the mixture along with lithium-based salts (s).

The cathode current collector (ie, cathode side electrode) 22 comprises any metal cathode side electrode material such as titanium (Ti), platinum (Pt), nickel (Ni), aluminum (Al), or titanium nitride (TiN). But it may be. The cathode current collector 22 may include a single layer of metal cathode side electrode material or a material stack containing at least two different metal cathode side electrode materials. In one example, the cathode current collector 22 includes a stack of titanium (Ti), platinum (Pt), and titanium (Ti) from bottom to top. In one embodiment, the metal electrode material that provides the cathode current collector 22 may be the same as the metal electrode material that provides the anode current collector 10. In another embodiment, the metal electrode material that provides the cathode current collector 22 may differ from the metal electrode material that provides the anode current collector 10. The cathode current collector 22 may have a thickness within the range described above with respect to the anode current collector 10. The cathode current collector 22 may be formed using one of the deposition processes described above for the formation of the anode current collector 10. For slurry-based cathode materials, metal foil may be used during the casting process.

Here, with reference to FIG. 2, another exemplary rechargeable lithium-ion battery according to a second embodiment of the present application is shown. In the exemplary lithium-ion battery shown in FIG. 2, the interface additive material layer 24 is arranged between the porous region 1 (that is, the top porous layer 17) of the anode structure 12 and the electrolyte region 18. Is similar to the rechargeable lithium-ion battery stack shown in FIG. Specifically, the exemplary rechargeable lithium-ion battery shown in FIG. 2 is defined in more detail below with the anode current collector 10 defined above, the anode structure 12 defined above, and the following herein. Includes a battery material stack of the interfacial additive material layer 24 defined above, the electrolyte region 18 defined above, the lithium-containing cathode material layer 20 defined above, and the cathode current collector 22 defined above. The battery material stack shown in FIG. 2 may have other orientations in addition to those shown in FIG. For example, the battery material stack may be flipped 180 °.

The interface additive (eg, dielectric material) layer 24 is present on the exposed surface of the porous region 1 (ie, the top porous layer 17) of the anode structure 12. The layer 24 may have a single layer structure or a multi-layer structure. The interfacial additive material layer 24 may include any interfacial additive material layer, such as carbon-based materials, or oxides of gold or dielectric materials, such as aluminum oxide. The interfacial additive material is any combination of electrically insulating and ionic conductive components of Li ions, such as, but not limited to _{, LiNbO 3} , LiZrO ₂ , Li ₄ SiO ₄ , or Li ₃ PO _4. It may be a mixture with. The interface additive material layer 24 may have a thickness of 1 nm to 50 nm. The interfacial additive material layer 24 may be formed using a deposition process that includes, for example, chemical vapor deposition, plasma-enhanced chemical vapor deposition, or atomic layer deposition. The interfacial additive material layer 24 can allow a high degree of chemical and physical interoperability between the electrolyte and the electrode layer under repeated electrochemical conditioning. The interface additive material layer 24 can maintain structural rigidity against overlapping interfaces, thereby enabling high ionic conductivity and reducing the internal resistance of the cell. In addition, the interface additive material layer 24 can provide electrical insulation at the interface, preventing cell leakage or short circuits through spatial control of the electrically conductive components within the battery. The interface additive material layer 24 described above can be continuous or patterned.

Here, with reference to FIG. 3, another exemplary rechargeable lithium-ion battery according to a third embodiment of the present application is shown. The exemplary rechargeable lithium-ion battery shown in FIG. 3 is shown in FIG. 1, except that the interfacial additive material layer 26 is located between the electrolyte region 18 and the lithium-containing cathode material layer 20. It is similar to a rechargeable lithium-ion battery stack. Specifically, the exemplary rechargeable lithium-ion battery shown in FIG. 3 comprises an anode current collector 10 as defined above, an anode structure 12 as defined above, and an electrolyte region 18 as defined above. Includes a battery material stack of a surfactant material layer 26 as defined in more detail below, a lithium-containing cathode material layer 20 as defined above, and a cathode current collector 22 as defined above. The battery material stack shown in FIG. 3 may have other orientations in addition to those shown in FIG. For example, the battery material stack may be flipped 180 °.

The interface additive material layer 26 may contain any of the above-mentioned interface additive materials with respect to the interface additive material layer 24. The interface additive material layer 26 may have a thickness of 1 nm to 20 nm in order to minimize the increase in cell internal resistance. The interfacial additive material layer 26 may be formed using a deposition process that includes, for example, chemical vapor deposition, plasma-enhanced chemical vapor deposition, or atomic layer deposition. The interface additive material layer 26 can maintain structural rigidity against overlapping interfaces, thereby enabling high ionic conductivity and reducing the internal resistance of the cell. In addition, the interface additive material layer 26 can provide electrical insulation at the interface, preventing cell leakage or short circuits through spatial control of the electrically conductive components within the battery.

Here, with reference to FIG. 4, an exemplary rechargeable lithium-ion battery according to a fourth embodiment of the present application is shown. In the exemplary rechargeable lithium-ion battery shown in FIG. 4, the interface additive material layer 24 is arranged between the porous region 1 (that is, the top porous layer 17) and the electrolyte region 18 of the anode structure 12, and the electrolyte. It is similar to the rechargeable lithium-ion battery stack shown in FIG. 1, except that another interfacial additive material layer 26 is disposed between the region 18 and the lithium-containing cathode material layer 20. Specifically, the exemplary rechargeable lithium-ion battery shown in FIG. 4 has an anode current collector 10 as defined above, an anode structure 12 as defined above, and an interfacial dielectric material layer 24 as defined above. The battery material of the electrolyte region 18 defined above, the interfacial dielectric material layer 26 defined above, the lithium-containing cathode material layer 20 defined above, and the cathode current collector 22 defined above. Includes stack. The battery material stack shown in FIG. 4 may have other orientations in addition to those shown in FIG. For example, the battery material stack may be flipped 180 °.

Here, with reference to FIG. 5, an exemplary rechargeable lithium-ion battery according to a fifth embodiment of the present application is shown. The exemplary rechargeable lithium-ion battery shown in FIG. 5 is shown in FIG. 1 except that the porous region of the anode structure 12 (including the porous region 1 and the porous region 2) is patterned. It is similar to the rechargeable lithium-ion battery stack. A patterned porous region containing both porous regions 1 and 2 (not shown individually) is designated element 16P in FIG. 5 of the present application. Specifically, the exemplary lithium-ion battery shown in FIG. 5 has the anodic current collector 10 defined above and the pattern forming porous region 16P (including porous regions 1 and 2) defined above. Includes a battery material stack of an anode structure 12 having the above, an electrolyte region 18 as defined above, a lithium-containing cathode material layer 20 as defined above, and a cathode current collector 22 as defined above. The battery material stack shown in FIG. 5 may have other orientations in addition to those shown in FIG. For example, the battery material stack may be flipped 180 °.

The interface additive material layer 24 may be formed between the pattern-forming porous region 16P and the electrolyte region 18, or the interface additive material layer 26 is formed between the electrolyte region 18 and the lithium-containing cathode material layer 20. It may be, or both. Patterning of porous regions (including porous regions 1 and 2) is performed using conventional patterning techniques, including, for example, lithography and etching, perhaps in combination with mechanical grinding / polishing, and doping. May be good. In some embodiments, patterning of the porous regions (16, 17) may be performed by simple selective doping of silicon, for example by ion implantation, epi, or thermal doping. The pattern-forming porous region 16P, which collectively includes the porous regions 1 and 2, may provide a means for further increasing the capacitance and kinetic (power) capacity of the anode structure 12 of the present application. .. The pattern-forming porous region 16P, which collectively includes the porous regions 1 and 2, may also provide a faster charging rate.

Here, with reference to FIGS. 6A-6B, an exemplary rechargeable lithium-ion battery according to a sixth embodiment of the present application is shown. In the exemplary rechargeable lithium-ion battery shown in FIGS. 6A and 6B, the porous region (including the porous region 1 and the porous region 2) of the anode structure 12 is patterned, and the lithium-containing cathode material layer is formed. 20 is similar to the lithium-ion battery stack shown in FIG. 1, except that it is also patterned. The patterned porous region (including the porous regions 1 and 2) is shown as element 16P in FIGS. 6A-6B of the present application, and the patterned lithium-containing cathode material layer is shown in FIGS. 6A of the present application. In ~ 6B, it is shown as element 20P. Specifically, the exemplary lithium-ion batteries shown in FIGS. 6A-6B have an anode current collector 10 as defined above and a patterning porous region 16P (porous regions 1 and 2) as defined above. Includes a battery material stack of an anode structure 12 having (including), an electrolyte region 18 as defined above, a pattern-forming lithium-containing cathode material layer 20P as defined above, and a cathode current collector 22 as defined above. .. The battery material stacks shown in FIGS. 6A-6B may have other orientations in addition to those shown in FIGS. 6A-6B. For example, the battery material stack may be flipped 180 °.

In one embodiment, as shown in FIG. 6A, the pattern-forming battery material stack components 16P and 20P face each other, eg, the higher (lower) regions of each component are in a non-complementary manner. The batteries face each other in the same lateral position. Alternatively, the pattern-forming battery material stack components 16P and 20P may have a complementary shape that fits like a keyway and a key as shown in FIG. 6B. In this embodiment, in addition to the thickness of the electrolyte (the electrolyte fills all the space between the battery components 16P and 20P), the relative proximity of the patterning electrodes to each other makes the counter electrodes specific close to each other. It can be controlled by aligning with the electrodes. The interface additive material layer 24 may be formed between the pattern-forming region 16P (collectively containing the porous regions 1 and 2) and the electrolyte region 18, or the electrolyte region 18 and the pattern-forming lithium-containing cathode material layer may be formed. The interface additive material layer 26 may be formed between the 20P and 20P, or both.

Patterning of the lithium-containing cathode material layer 20P may be performed using conventional patterning techniques, including, for example, lithography and etching, or by using a lift-off process. The pattern-forming lithium-containing cathode material layer 20P may be complementary or non-complementary with respect to the pattern-forming porous region 16P. The pattern-forming lithium-containing cathode material layer 20P may provide a further increase in the capacity and kinetic charge / discharge capacity of the lithium-ion batteries of the present application. Collectively, the pattern-forming porous regions 16P (collectively containing the porous regions 1 and 2) and the pattern-forming lithium-containing cathode material layer 20P provide maximized battery capacity and possibly battery charging speed. It may be increased, which means that the pattern size is finally the volume of space between the pattern-forming porous region 16P (collectively containing the porous regions 1 and 2) and the pattern-forming lithium-containing cathode material layer 20P. By being able to influence and determine the thickness, density, and other physical properties of the electrolyte region 18, as well as the fixed proximity, it could directly affect the ion-electron transfer properties throughout the battery stack.

Here, with reference to FIG. 7A, a schematic diagram showing the entire process of using the crystalline p-type silicon material 50 for the anode etching method described herein is shown. In particular, this process begins with the step of providing the crystalline p-type silicon material 50, followed by anode etching to result in porous region 1 (PR1: Porous Region 1) (ie, top porous layer 17) and porosity. An anode structure is provided that includes the region 2 (PR2) (ie, the bottom porous layer 16) as well as the non-etched portion of the original crystalline p-type silicon substrate that lies beneath the two porous regions. The non-etched portion of the original substrate defines the non-porous region 14 of the silicon substrate. In this drawing, the non-porous region 14 is also shown as element 50S. Note that the non-porous region 50S has the same characteristics as the non-porous region 14 described above.

FIG. 7B is a transmission electron microscope (TEM) (cross-sectional view) of an experimentally produced porous silicon substrate, such as that shown in FIG. 7A. This TEM microscopic view clearly shows the two porous regions PR1 (ie, top porous layer 17) and PR2 (ie, bottom porous layer 16) shown in FIG. 7A, where the porous region 1 is about. It has an order thickness of 30 nm, and the porous region 2 is considerably thicker than the porous region 1.

FIG. 8A is a high resolution transmission electron microscope view of an embodiment of the porous silicon material shown in FIG. 7A of the present specification. The scale lines in this drawing indicate that the total thickness of the porous region 1 is about 29 nm. FIG. 8B is a secondary ion mass spectrometry (SIMS) profile of the porous silicone material shown in FIG. 8A. This SIMS profile shows that the concentrations of carbon, oxygen, and fluorine elements in the first 30 nm of the porous silicon material are relatively low, which is directly related to the porous region 1 (tied by double-sided arrows). (As indicated by the dotted boxes in FIGS. 8 (A) and 8 (B)).

Here, referring to FIGS. 9A to 9C, a series of steps are shown as a flow chart, and the porous silicon electrode (that is, the non-porous region 50S, the porous region 2 (PR2), and the porous region 1 (PR1)) is shown. The operation of charge storage through the electrode material when a liquid-based electrolyte is used is shown with the seed layer 52 during the charge and discharge cycles, plus 5 cycles (Figure). SEM images of porous silicon electrodes at 9B) and about 250 cycles (FIG. 9C (B)) are shown. In particular, FIG. 9A (A) shows the porous silicon electrode shown and shown in FIG. 7A prior to incorporation into the electrochemical energy storage cell. The porous silicon electrode includes a non-porous region 50S, a porous region 2 (PR2), and a porous region 1 (PR1). FIG. 9A (B) shows the initial lithiolysis process of a porous silicon electrode when incorporated into a Li-ion electrochemical energy storage cell. During the initial exposure of the porous silicon electrode to the lithium ion-containing electrolyte, or during the first period of electrochemical lithiolysis of the porous silicon electrode, or during the initial charging of the porous silicon electrode, or a combination thereof. , The formation of a planar lithium-containing seed layer 52 occurs. As shown, the lithium-containing seed layer 52 is located above the porous region 1, and in some embodiments, a portion of the seed layer 52 may extend into the upper portion of the porous region 2. .. The surface of the top of the seed layer 52 is usually flat, that is, flat. FIG. 9A (C) is a schematic view of planar lithium plating that occurs during the charging process. In FIG. 9A (C), element 54 shows a planar lithium layer formed during this operating step. When the battery reaches full charge, the thickness of the plated lithium metal 54 on the seed layer 52 is determined by the working voltage range of lithium deintercalated from the lithium-containing cathode material layer and transferred from the electrolyte. It is proportional to the amount.

FIG. 9B is a scanning electron microscope cross-sectional view of the porous silicon electrode showing the plating phenomenon shown in FIG. 9A (C), in which a cross-sectional image of the electrode is shown in a charged state after about 250 charge / discharge cycles. It is being taken. In the charged state, the lithium ingress penetrates the porous region 1, but is observed only at the top of the porous region 2, which causes some cracks in the upper portion of the porous region 2. FIG. 9C (A) is a diagram showing lithium deplating that occurs during the discharge process, where a portion of the irreversibly plated lithium metal 54 remains on the top of the seed layer 52. Due to the electric discharge, the thickness of the remaining portion of the plated lithium metal 54 is substantially thinner than the thickness of the planar lithium layer 54 formed in the charged state shown in FIG. 9A (C). It should be noted that the thickness of the lithium metal layer decreases relatively as the battery approaches a sustainable discharge state, as determined by the working voltage range. 9C (B) is a scanning electron microscope cross-sectional view of the discharged state porous silicon electrode corresponding to FIG. 9C (A), which is charged and discharged five times. In one embodiment, the working voltage range is 4.2V to 3.0V. In one embodiment, the lithium-containing cathode material layer is a lithium cobalt oxide. The seed layer formation and lithium metal plating that occurs during charging and the lithium metal deplating that occurs during subsequent discharge are solid or liquid electrolytes, or any other type of electrolyte referred to herein. Observed for lithium-ion batteries containing.

In some embodiments, the rechargeable lithium-ion batteries of the present application can be charged and discharged more than 200 cycles when using sustainable working voltages such as those described above. After 200 charge and discharge cycles, the surface of the plated lithium metal is nominally continuously planar on average.

Here, with reference to FIGS. 10A-10C, an actual SEM image for an all-solid-state lithium-ion battery containing a structure similar to that shown in FIG. 1 according to the present application is shown, where the electrolyte region 18 is, for example, LiPON. It is a solid material of. This structure also includes the anode structure 12 shown in FIG. 1 or FIG. 9A (A). In particular, FIG. 10A is an SEM of the structure before charge or discharge of constant current or constant potential induction, FIG. 10B is another SEM of the structure after the charge and discharge cycle of 6, and FIG. 10C is the charge and discharge of 67. Yet another SEM image of the post-cycle structure.

The SEM of FIG. 10A is a cross-sectional SEM image of an all-solid-state battery before electrochemical charging or discharging induced at a constant current or potential, with a porous silicon electrode (ie, a non-porous region (not shown)). The anode structure including the porous region 2 (PR2) and the planar porous region 1 (PR1)) is shown, and here, the solid electrolyte region 18 exists on the porous region 1 (PR1). FIG. 10B is a cross-sectional SEM image of the all-solid-state cell shown in FIG. 10A after the constant current induced charging and discharging cycle of 6, in which the porous region 2 (PR2) and the lithium-containing seed layer 52 are formed from the bottom to the top. A porous region 1 (PR1) containing is observed. In particular, the off-white feature originating from the porous region 1 (PR1) / solid electrolyte region 18 interface is clearly observed, which constitutes the lithium-containing seed layer 52 or during the charge / discharge cycle of 6. It is believed to represent the reaction of air with a lithium-rich material that constitutes or both of the plated lithium metal present on the lithium-containing seed layer 52 formed in. FIG. 10C is a cross-sectional SEM image of the all-solid-state cell shown in FIG. 10A after the constant current induced charge and discharge cycle of 67, here with substantially the original porous region 2 (PR2) from the bottom to the top. Partially lithiated porous region 2 (PR2), planar formation of lithium metal-containing dendrite features mixed with solid electrolyte material in porous region 1 (PR1), and electrolyte region 18 were observed. NS. During the initial exposure of the porous silicon electrode to the lithium ion-containing electrolyte, or during the first period of electrochemical lithiolysis of the porous silicon electrode, or during the initial charging of the porous silicon electrode, or a combination thereof. , The formation of a planar lithium-containing seed layer 52 occurs. As shown, the lithium-containing seed layer 52 is located within the porous region 1 area, and a portion of the seed layer 52 may extend into the upper portion of the porous region 2. As observed in FIGS. 10A and 10B, the top surface of the seed layer 52 is usually flat, i.e. planar, and prior to the cycle, PR1 and the seed layer 52 are in close planar contact with the electrolyte region 18. Are in contact. This planar lithium metal-containing seed layer is believed to act as a host or nucleation site for subsequent plating / exfoliation of the lithium metal, respectively, during subsequent charge / discharge cycles. After the charge / discharge cycle of 6, the lithium-rich material forming the seed layer and / or the lithium metal-plated seed layer fixes itself during destruction and cutting of the cell to obtain the SEM image of FIG. 10B. It changes from the flat state. It is observed that each of these lithium metal-containing layers reacts here with chemicals in the ambient air to form off-white features, which emerge / generate from the PR1 / solid electrolyte region 18 interface region. In FIG. 10C, after 56 charge / discharge cycles, a substantially original porous region 2 (PR2) region is observed, on which a partially lithium-rich porous region 2 is observed (PR2). , The formation of a lithium rich dendrite type planar layer of about 183 nm is observed in the porous region 1 (PR1) region above it, and the LiPON electrolyte region is observed on it. In particular, the lithium-rich dendrite feature forms planarly in / above the porous region 1 (PR1) region and remains stable during cell destruction and cutting after 67 charge / discharge cycles. The observation that there is close continuous contact between the solid electrolyte region 18 and the lithium metal rich dendrite features in / above the porous region 1 (PR1) region is the liquid shown in FIGS. 9A-9C. It demonstrates the high effectiveness of the present invention as a stable lithium metal host porous silicon anode in an all-solid-state battery, in addition to a stable lithium metal host porous silicon anode-containing battery containing an electrolyte.

In some embodiments, during multiple charge / discharge cycles, in addition to dendrite formation at the lithium metal / electrolyte interface, above / along the (111) crystalline silicon surface at the bottom porous layer / top porous layer interface. In addition, a unique dendrite formation occurs.

The rechargeable lithium-ion batteries shown in FIGS. 1-5, 6A, and 6B may have any size and / or shape. An example of the range includes any value from 10 μm to less than 1 mm (smaller) and larger than 1 mm. In one example, the size of the rechargeable lithium-ion battery may be 100 μm × 100 μm × 100 μm. In another example, the size of the rechargeable lithium-ion battery may be 50 mm x 50 mm x 5 mm. In some embodiments where a semiconductor-based substrate is present, the rechargeable lithium-ion batteries shown in FIGS. 1-5, 6A and 6B are, for example, transistors, capacitors, diodes, laser diodes, light emitting devices, photovoltaics. It may be integrated with semiconductor devices including devices, central processing units, silicon-based device structures and the like. The batteries that power the semiconductor device may be on either the same side or the opposite side of the semiconductor substrate.

The integration may be done in two ways: 1) as before, by preliminary patterning, lithography, etching of the semiconductor substrate prior to anodization and fabrication of the porous semiconductor region, or 2) selective doping, such as ion implantation, followed by, for example, a furnace or By thermal annealing such as lamp or laser annealing, or by selective epitaxial growth. The device may be placed on the same original semiconductor substrate, integrated with the same original semiconductor substrate, or placed on an adjacent semiconductor substrate within a given working proximity (same battery). It can be on the other side or the other side).

Here, the method of manufacturing the anode structure 12 of the present application will be considered in more detail. The method of this application provides: 1) The "growth" or formation or etching of a porous semiconductor region connected to a non-porous semiconductor region (eg, single crystal silicon material), which can then be integrated with / into other silicon-based technologies. 2) Successful integration and use of liquid, solid and semi-solid electrolytes, and their high performance in rechargeable batteries (universal by any electrolyte). In addition, 3) the mirror-like smooth surface of the starting silicon substrate allows the thickness of the solid electrolyte to be controlled in the nm region, which enables a high degree of control of battery performance, charging speed, and ion mobility, and also allows physical control. Suitable for deposited electrolytes.

In particular, the anodic structure 12 of the present application can be prepared using an anodizing process, in which the substrate containing at least the upper region of the p-type silicon material is immersed in a concentrated HF solution (49%). Current is applied by platinum as the anode and substrate as the cathode. The anodizing process is carried out using a constant current source operating at a current density of ^{0.05 mA / cm 2} to 150 mA / cm ^{2, where mA is milliamperes.} In some examples, the current densities are 1 mA / cm ² , 2 mA / cm ² , 5 mA / cm ² , 50 mA / cm ² , or 100 mA / cm ² . In a preferred embodiment, the current density is 1 mA / cm ² to 10 mA / cm ² . The current density may be applied for 1 second to 5 hours. In some examples, the current density may be applied for 5 seconds, 30 seconds, 20 minutes, 1 hour, or 3 hours. In certain embodiments, the current densities may be applied specifically for a dope level in the range 10 ¹⁹ cm ^{3 for 10 to 1200 seconds.} The anodizing process is usually carried out at nominal room temperature (20 ° C to 30 ° C) or at a temperature slightly above room temperature. Following the anodizing process, the structure shown in FIG. 7B is usually rinsed with deionized water and then dried.

In some embodiments, after anodizing, the anodic structure 12 may be cut to the desired dimensions before use. In some embodiments, the anode structure 12 may be placed on and optionally coupled to the anode current collector 10 as defined above, followed by various other components of the lithium ion battery. It may be formed. In another embodiment, the anode structure 12 is placed on, optionally there, an electrolyte region 18 of a prefabricated battery material stack that also includes a cathode region including a lithium-containing cathode material layer 20 and a cathode current collector 22. May be combined with.

With reference to FIG. 11, a flow chart showing an embodiment for making the anode structure 12 of the present application is shown. In particular, the anode structure 12 including the porous region 1 and the porous region 2 and the non-porous region 14 (or 50S) discussed above can be formed using the processing steps shown in FIG. In one embodiment, the substrate 12 may be entirely composed of a p-type doped crystalline silicon material, while in other embodiments, another silicon material or germanium (doped) underneath the p-type doped silicon material. Or both non-doped) may be present. This method is the first step, i.e. a p-doped silicon substrate with a mixture of ammonium hydroxide, deionized water and hydrogen peroxide (5: 1: 1 v / v) at 60 ° C to 80 ° C. It may include step 1 (70) of washing for about 10 minutes. Then, in step 2 (72), the washed p-doped silicon substrate is immersed in 49% hydrofluoric acid, after which an electric current is applied to initiate electrochemical anodic oxidation (ie, anodic etching). NS. In one embodiment, the applied current is a constant current in the range of ^{1 mA / cm 2} to 10 mA / cm ^2. In step 3 (74), anodizing etching is continued using the following electrochemical anodizing conditions. 10s to 2000s at nominal room temperature (20 ° C to 30 ° C) and 5mA / cm ^{2 or less.} After etching, in step 4 (76), the etched silicon substrate is rinsed with deionized water and then dried. The anodizing process defined in step 3 converts the upper portion of the substrate containing the p-doped silicon into a porous region 1 and a porous region 2, and the underlying substrate is unaffected by the anodizing process described above. A non-porous region 14 (or 50S) is formed.

In any of the above embodiments as shown in FIGS. 1-5, 6A, and 6B, the lithium-containing cathode material layer 20 has a particle size of less than 100 nm and a particle boundary of ^{10 10} cm- ^{2 or more.} It may contain particles having a density. In some embodiments, the particle size of the individual particles constituting the lithium-containing cathode material layer 20 is from 1 nm to less than 100 nm. In some embodiments, the boundary density can range from 10 ¹⁰ cm- ² to 10 ¹⁴ cm- ² . As used herein, the term "particle boundary" is defined as the interface between two particles of a material. Particle boundaries are present in the lithium-containing cathode material layer 20 in a somewhat random orientation. Some of the particle boundaries completely make the cathode material so that one end of the particle boundary is on the surface of the bottom of the cathode material and the other end of the particle boundary is at the top of the cathode material. It may pass and extend. In this embodiment, the particle boundaries are not oriented perpendicular to the top and bottom surfaces of the lithium-containing cathode material layer 20.

In any of the above embodiments as shown in FIGS. 1-5, 6A, and 6B, the lithium-containing cathode material layer 20 may have a columnar microstructure with columnar particle boundaries. good. The columnar particle boundaries are oriented perpendicular to the top and bottom surfaces of the lithium-containing cathode material layer 20. In such an embodiment, the lithium-containing cathode material layer 20 has a plurality of fin-like structures in the cathode material. The lithium-containing cathode material layer 20 having a columnar fine structure has a particle size of less than 100 nm and a density of columnar particle boundaries of ^{10 10} cm- ^{2 or more.} In some embodiments, the particle size of the individual particles constituting the lithium-containing cathode material layer 20 is from 1 nm to less than 100 nm. In some embodiments, the density of columnar particle boundaries can be 10 ¹⁰ to 10 ¹⁴ cm- ² . In one embodiment, the electrically conductive cathode material is the lithium-containing material as defined above.

For example, in the rechargeable battery material stacks shown in FIGS. 1-5, 6A, 6B, etc. of the present application, together with the anode structure 12 of the present application, a particle size of less than 100 nm and a particle boundary of ^{10 10} cm- ^{2 or more.} The presence of a lithium-containing cathode material layer 20 containing dense particles or a lithium-containing cathode material layer 20 having a columnar microstructure allows for high-speed, substantially or totally vertical ions or Li ions. Transport is facilitated, which can result in fast rechargeable batteries.

A lithium-containing cathode material layer 20 containing an anode structure 12 and particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or a lithium-containing cathode material layer 20 having a columnar microstructure. The rechargeable battery including the above may indicate a charging speed of 5C or more, where C is the total battery capacity per hour. In some embodiments, a lithium-containing cathode material layer 20 containing an anode structure 12 and particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ^{2 or greater, or a columnar microstructure.} The charging speed of the battery including the lithium-containing cathode material layer 20 having the same can be 5C to 1000C or more. In addition, a lithium-containing cathode material layer 20 containing an anode structure 12 and particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or a lithium-containing cathode having a columnar microstructure. The rechargeable battery including the material layer 20 may have a capacity of 100 mAh / gm cathode material or more.

The lithium-containing cathode material layer 20 containing particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or the lithium-containing cathode material layer 20 having a columnar microstructure, is a sputtering process. May be formed using. In some embodiments, no subsequent annealing is performed after sputtering of the cathode material. The cathode material sputtered without annealing provides a lithium-containing cathode material layer 20 containing particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ^{2 or greater.} In another embodiment, the cathode material may be sputtered followed by annealing to provide a lithium-containing cathode material layer 20 having a columnar microstructure. Annealing is performed at a temperature below 300 ° C. to preserve charging rates greater than 5C. In one embodiment, sputtering may include the use of any precursor source material or a combination of multiple precursor source materials. In one example, a lithium precursor source material and a cobalt precursor source material are used in the formation of the lithium cobalt mixed oxide. Sputtering may be carried out in a mixture of the inert gas and oxygen. In these embodiments, the oxygen content of the inert gas / oxygen mixture may be from 0.1 to 70 percent percent, with the remainder of the mixture containing the inert gas. Examples of the inert gas that can be used include argon, helium, neon, nitrogen, or any combination thereof.

The lithium-containing cathode material layer 20 containing particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or the lithium-containing cathode material layer 20 having a columnar microstructure, is 10 nm to 20 μm. May have a thickness of. For a lithium-containing cathode material layer 20 containing particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or a lithium-containing cathode material layer 20 having a columnar microstructure, as described above. Other thicknesses that are less than or greater than the thickness value of are also used. A thick lithium-containing cathode material layer 20 containing particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or a lithium-containing cathode material layer 20 having a columnar microstructure is a battery. Increased battery capacity can be provided due to the increased area or volume for storing charges.

Although the present application has been specifically shown and described with respect to its preferred embodiments, it will be appreciated by those skilled in the art that the aforementioned and other modifications of form and detail may be made without departing from the ideas and scope of the present application. Will be. Accordingly, this application is intended to be within the appended claims, without limitation to the exact form and details described and illustrated.

Claims (45)

Lithium-containing cathode material layer and
It is a single structure and has an anode structure including a non-porous region and a porous region, and the porous region has a top porous layer having a first thickness and a first porosity, and the top porous region. It includes a bottom porous layer that is located below the sex layer and forms an interface with the non-porous region, and at least the upper portion of the non-porous region and the entire porous region are made of silicon. With the anode structure, the bottom porous layer has a second thickness greater than the first thickness and a second porosity greater than the first porosity.
A battery comprising an electrolyte region located between the top porous layer of the anode structure and the lithium-containing cathode material layer. The battery according to claim 1, wherein the top porous layer, the bottom porous layer, and the non-porous region are entirely composed of silicon. The battery according to claim 2, wherein the silicon is a single crystal. The battery according to claim 1, wherein the lower portion of the non-porous region is composed of a doped silicon or a doped silicon-germanium alloy having a germanium content of less than 10 atomic percent. The first porosity of the top porous layer has an average porosity of less than 3 nm, and the second porosity of the bottom porous layer has an average porosity greater than 3 nm. The battery according to claim 1. The battery according to claim 1, wherein the first thickness of the top porous layer is 50 nm or less. The battery according to claim 1, wherein the second thickness of the bottom porous layer is 0.1 μm to 20 μm. The battery according to claim 1, wherein the non-porous region is composed of p-doped silicon which is a single crystal. The battery according to claim 1, wherein the non-porous region and the porous region are entirely composed of p-type doped silicon. The battery according to claim 1, wherein the silicon is p-doped silicon having a p-type dopant concentration in the range of ^{10 19} cm ^-3. The battery according to claim 1, wherein the silicon is boron-doped silicon. The battery according to claim 1, further comprising an anode current collector in contact with the surface of the non-porous region of the anode structure. The battery according to claim 1, further comprising a cathode current collector electrode that contacts the surface of the lithium-containing cathode material layer. The electrolyte region is composed of a solid electrolyte, a liquid electrolyte, a semi-solid electrolyte, an electrolyte that is originally a liquid and becomes a solid, a gel electrolyte, a polymer-containing electrolyte, a composite cathode / electrolyte combination, or any combination thereof. Batteries listed in. The battery according to claim 1, wherein the electrolyte region is entirely composed of a solid electrolyte. The battery according to claim 1, further comprising an interface additive material layer located between the top porous layer of the anode structure and the electrolyte region. The battery according to claim 1, further comprising an interface additive material layer located between the electrolyte and the lithium-containing cathode material layer. A first interfacial additive material layer located between the top porous layer of the anode structure and the electrolyte region, and a second interfacial additive located between the electrolyte and the lithium-containing cathode material layer. The battery according to claim 1, further comprising a material layer. The battery according to claim 1, wherein the porous region including the top and bottom porous layers is patterned. The battery according to claim 19, wherein the lithium-containing cathode material layer is patterned. The battery according to claim 1, wherein the porous region is located at the top, bottom, or side of any three-dimensional structure. The lithium-containing cathode material layer is selected from a lithium-containing material containing particles having a particle size of less than 100 nm and ^{a particle boundary density of 10 10} cm- ² or more, or a lithium-containing material having a columnar microstructure. The battery according to claim 1. 15. The battery of claim 15, wherein the battery further comprises a seed layer located on the surface of the top porous layer of the anode structure, the seed layer being a planar conformal lithium-containing material. A method for producing a lithium battery anode structure, wherein the method is
A step of immersing a substrate including at least the upper portion composed of p-doped silicon in concentrated hydrogen fluoride using anodizing equipment, and
The step of applying an electric current to the anodizing equipment and
The anodizing step comprises a step of electrochemically anodizing the substrate, the step of anodizing provides a structure having a single configuration and including a non-porous region and a porous region, wherein the porous region is a first. A top porous layer having a thickness of 1 and a first porosity and a bottom porous layer located below the top porous layer and forming an interface with the non-porous region, said non-porous. At least the upper portion of the porous region and the entire porous region are made of silicon, and the bottom porous layer has a second thickness larger than the first thickness and the first porosity. A method having a second porosity greater than. 24. The method of claim 24, further comprising cleaning the substrate prior to the dipping step. 24. The method of claim 24, further comprising rinsing the structure with deionized water and drying after the anodizing step. 24. The method of claim 24, wherein the entire substrate is made of p-doped silicon. 27. The method of claim 27, wherein the p-doped silicon is a single crystal. The washing step involves mixing a mixture of deionized water, ammonium hydroxide and hydrogen peroxide (volume ratio 5: 1: 1) at a temperature of 60 ° C to 80 ° C for a period of 5 to 30 minutes. 25. The method of claim 25, which is performed by the step of rinsing with deionized water after use. 24. The method of claim 24, wherein the concentrated hydrogen fluoride is a 49% hydrofluoric acid solution. 24. The method of claim 24, wherein the current is ^{a constant current in the range of 1 mA / cm 2} to 10 mA / cm ^2. 24. The method of claim 24, wherein the step of anodizing the substrate is performed at a temperature of 20 ° C to 30 ° C. 32. The method of claim 32, wherein the step of anodizing the substrate is ^{performed at a current of 5 mA / cm 2} or less for 10 to 2000 seconds. 24. The method of claim 24, wherein the top porous layer, the bottom porous layer, and the non-porous region are entirely composed of silicon. 34. The method of claim 34, wherein the silicon is a single crystal. 24. The method of claim 24, wherein the lower portion of the non-porous region is composed of a doped silicon or a doped silicon-germanium alloy having a germanium content of less than 10 atomic percent. The first porosity of the top porous layer has an average porosity of less than 3 nm, and the second porosity of the bottom porous layer has an average porosity greater than 3 nm. The method according to claim 24. 24. The method of claim 24, wherein the first thickness of the top porous layer is 50 nm or less. 24. The method of claim 24, wherein the second thickness of the bottom porous layer is 0.1 μm to 20 μm. 24. The method of claim 24, wherein the non-porous region is composed of p-doped silicon, which is a single crystal. 24. The method of claim 24, wherein the non-porous region and the porous region are entirely composed of p-type doped silicone. 24. The method of claim 24, wherein the silicon is a p-doped silicon having a p-type dopant concentration in the range of ^{10 19} cm ^-3. 24. The method of claim 24, wherein the silicon is boron-doped silicon. 24. The method of claim 24, further comprising the step of patterning the porous region, including the top and bottom porous layers. 24. The method of claim 24, wherein the porous region is formed at the top, bottom, or side of any three-dimensional structure.

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