KR20230128264A - Advanced Li-Ion Energy Storage Devices - Google Patents

Abstract

Lithium ion capacitors include binder-free positive and negative active layers. Capacitors exhibit high energy density, power density and cycle life and provide a good performance compromise between electrical double layer capacitors and lithium ion batteries.

Description

Advanced Li-Ion Energy Storage Devices

Cross reference to relevant literature

This application is filed in US Provisional Patent Application No. 63/093441 (Title of Invention: "Advanced Lithium-Ion Energy Storage Device", Application Date: October 19, 2020), and US Provisional Patent Application No. 63/021492 (Title of Invention: "Wide Temperature Electrolyte", filing date: May 8, 2020); U.S. Patent No. 10,600,582 entitled "Composite Electrode", Issued on March 24, 2020; U.S. Patent No. 9,001,495 entitled "High power and high energy electrodes using carbon nanotubes", Registration Date: April 7, 2015, also U.S. Patent No. 9,218,917 entitled "Energy storage media for ultracapacitors" , Registration Date: December 22, 2015), the entire disclosures of which are incorporated herein by reference for any purpose.

Technical Field of Invention

The invention disclosed herein relates to energy storage devices, and more particularly to lithium-containing electrodes made substantially free of binder materials.

Lithium (Li)-ion batteries (LiBs) and electric double layer capacitors (EDLCs) are two widely used electrochemical energy storage devices. A typical LiB is made of a lithium (Li) intercalated anode and a Li metal oxide cathode (hence the reduction process or Faraday mechanism of energy storage), whereas an EDLC is made of high surface area activated carbon (AC) for both anode and cathode (hence the double layer capacitance or a non-Faraday form of energy storage). As a result of different energy storage mechanisms, these devices are distinguished in their energy and power performance. LiB exhibits a high specific energy of eg 100 to 250 Wh/kg; However, LiB also has a low specific power of less than 0.5 kW/kg and a poor cycle life of less than 5,000 cycles. EDLC has a high specific power of 10 kW/kg and a long cycle life of more than 100,000 cycles; However, EDLC shows a much lower specific energy of less than 6 Wh/kg.

An energy storage device that can combine the advantages of LiB and EDLC into a single form is highly desirable. As a next-generation supercapacitor, the Li-ion capacitor (LiC) is an advanced energy storage device comprising an EDLC cathode and a pre-lithiated anode, with ions moving back and forth between the cathode and anode during charging and discharging processes. Because of the use of pre-lithiated, low surface anode materials, LiC can be charged to voltages as high as 4.0V, much higher than EDLC and comparable to LiB. Although LiC can achieve a much higher power density than LiB, the energy density of LiC is about 10 to 20 Wh/kg, which is still much lower than LiB. Therefore, the energy density of LiC energy storage devices needs to be further improved.

What is needed are methods and apparatus to improve the possibilities of LiC technology. Advantageously, the method and apparatus also reduce the cost and time required for manufacturing.

In one embodiment, a lithium ion capacitor device is provided. The device includes an anode comprising a network of carbon substantially free of binder material; a negative electrode comprising a network of carbon substantially free of binder material, separated from the positive electrode by a separator; and a lithium film disposed on the negative electrode to provide pre-lithiation of the capacitor; At least one of the anode and cathode comprises: a network of high-aspect-ratio carbon elements defining voids within the network; and a plurality of electrode active material particles disposed in voids within the network and entangled in the network.

In some embodiments, the high aspect ratio carbon elements include elements each having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is at least 10 times the length ratio of the minor dimension. A high aspect ratio carbon element may include elements each having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is at least 100 times the length ratio of the minor dimension. The high aspect ratio carbon element may include elements each having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is at least 1,000 times the length ratio of the minor dimension. The high aspect ratio carbon element may include elements each having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is at least 10,0000 times the length ratio of the minor dimension. A high aspect ratio carbon element may include elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being at least 10 times the length ratio of each minor dimension. The high-aspect-ratio carbon element may include elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being at least 100 times the length ratio of each minor dimension. The high aspect ratio carbon element may include elements each having one major dimension and two minor dimensions, wherein the ratio of the lengths of each major dimension is at least 1,000 times the length of each minor dimension. The high aspect ratio carbon element may include elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being at least 10,000 times the length ratio of each minor dimension. The high aspect ratio carbon element may include carbon nanotubes or carbon nanotube bundles. The high aspect ratio carbon element may include graphene flakes. The electrode active layer may contain less than 10% by weight of a polymeric binder disposed in the voids. The electrode active layer may contain less than 1% by weight of a polymeric binder disposed in the voids. The electrode active layer may contain less than 1% by weight of a polymeric binder disposed in the voids. The electrode active layer may be substantially free of polymeric materials other than surface treatment. The electrode active layer may be substantially free of polymeric material. The network may be at least 90% carbon by weight. The network may be at least 95% carbon by weight. The network can be at least 99% carbon by weight. The network can be at least 99.9 weight percent carbon. The network may include an electrically interconnected network of carbon elements exhibiting connectivity above the osmotic threshold. A network may define one or more highly electrically conductive pathways. The pathway may have a length greater than 100 μm. Pathways may have lengths greater than 1,000 μm. The pathway may have a length greater than 10,000 μm. The network may include one or more structures formed of carbon elements, the structures having an overall length that is at least 10 times the length of the largest dimension of the carbon elements. The network may include one or more structures formed of carbon elements, the structures having an overall length that is at least 100 times the length of the largest dimension of the carbon elements. The network may include one or more structures formed of carbon elements, the structures having an overall length that is at least 1,000 times the length of the largest dimension of the carbon elements. The positive electrode may include an electrode active material including at least one from the list consisting of activated carbon, carbon black, graphite, hard carbon, soft carbon, nanoform carbon, high aspect ratio carbon, and mixtures thereof. The positive electrode may comprise an electrode active material comprising activated carbon (AC) having a specific surface area in the range of 1000 to 3000 m 2 /g. The positive electrode may include an electrode active material including activated carbon (AC) having a particle size of D50≤10 μm. The negative electrode may include an electrode active material having a particle size of D50≤10 μm. The positive electrode may include an electrode active material including activated carbon (AC), carbon black (BC) and high-aspect-ratio carbon, wherein the mass ratio between the active material and the high-aspect-ratio carbon is in the range of 80:20 to 99:1. there is. The combined total thickness of the positive electrode and lithium film may range from 40 μm to 450 μm. The total thickness of the cathode may range from 20 μm to 350 μm. The thickness ratio of the total thickness of the positive active layer to the total thickness of the negative active layer may range from 1:2 to 3:1. The capacity ratio of the positive electrode active layer to the negative electrode active layer ranges from 1:12 to 1:2. The lithium film may include an ultra-thin lithium film including holes. A mass per unit area of the lithium source on the side of the negative electrode active layer may be in the range of 0.1 mg/cm 2 to 3 mg/cm 2 . The thickness of the lithium source on the side of the negative electrode active electrode layer may range from 2 to 50 μm. The surface area of the lithium film may be 25% to 100% of the surface area of the side surface of the negative electrode. The lithium film may include holes, and the area size percentage of the holes ranges from about 0.01% to about 75% of the total area of the film.

In another embodiment, a method for manufacturing a lithium ion capacitor is provided. The method includes providing an energy storage cell comprising: selecting an anode comprising a carbon network substantially free of binder material; selecting a negative electrode comprising a carbon network substantially free of binder material, separated from the positive electrode by a separator; and placing a lithium film on the negative electrode to provide pre-lithiation of the capacitor. and sealing the energy storage cell and electrolyte in a housing to provide a capacitor. A lithium ion capacitor may include the device described above.

The features and advantages of the present invention are apparent from the following description taken in conjunction with the accompanying drawings:
A series of micrographs, flow charts and performance graphics are provided.

Disclosed herein are methods and apparatus for making hybrid binder-free electrodes useful in energy storage devices. Advantageously, as a result of being substantially free of binder materials commonly used in the construction of electrodes, the electrodes disclosed herein can provide superior electrical performance and require fewer steps in the manufacturing process.

The energy storage devices disclosed herein combine the advantages of LiB and LiC while avoiding their inherent drawbacks, and thus bridge the gap between the high energy density provided by LiB and the high power density exhibited by LiC. First of all, the fundamental difference between these Li-ion energy storage devices and LiC is that hybrid Li-ion technology combines two separate energy storage devices by synergistically combining LiB and LiC cathode materials together to form a hybrid composite cathode. is to integrate into one. The non-Faraday capacitor material may initially be electrostatically charged until the potential of the electrode reaches the reduction potential of the faradaic battery material when the battery material is charged while holding the battery reduction potential constant. Once fully charged, the capacitor material is charged again until the limiting potential is reached across the capacitor material.

In general, the disclosed technology is a hybrid composite comprising a binder-free cathode electrode, a binder-free anode electrode, an organic solvent electrolyte solution having a lithium salt as a separator and electrolyte, and an ultra-thin lithium film (μ-Li) source. It relates to lithium ion energy storage devices. The ultra-thin lithium film may include a plurality of holes. Through the ultra-thin lithium film, the anode electrode is pre-doped with sufficient lithium ions. Pre-doping may occur by disposing an ultra-thin lithium film substantially on the surface of the anode electrode. The hybrid composite cathode may also be prepared using a polymeric binder-free manufacturing process, and the resulting capacity ratio of hybrid composite cathode to anode electrode may be between 0.1 and 1.2. The mass of the ultra-thin lithium film disposed on the anode electrode can be predetermined by a calculation formula to achieve high energy, power and long cycle life performance in a full cell format design.

A schematic diagram of an energy storage device is shown in FIG. 1 . In the example of FIG. 1 , the energy storage device (ESD) 10 is a three-layer cell. An opposing current collector 2 is hosted in the cathode material 3 . Collectively, current collector 2 and cathode material 3 provide each of the two cathodes 4 shown. An anode 8 is shown disposed between the cathodes 3 . In this example, anode 8 includes opposing layers of anode material 5 disposed on another current collector 6 . A lithium source 7 is disposed above each layer of anode material. In this example, current collector 2 for the cathode is made of aluminum, and current collector 6 for the anode is made of copper.

Referring to Figures 2A and 2B, an example of a cathode material 3 comprising activated carbon is shown. In these examples, SEM images of a cathode material 3 according to the prior art (FIG. 2A) and the teachings herein (FIG. 2B) are shown. As can be seen, the image for the cathode 4 disclosed herein contains significantly more carbon and, as can be easily guessed, allows greater energy storage than the device of FIG. 2A.

For purposes of discussion, two examples of cathode materials are presented herein. The first example includes an electrode with pure activated carbon (AC) (LiC with 0% lithium iron phosphate (LFP)); A second example includes a hybrid binder-free electrode (having an LFP to AC ratio of 20:80). In binder-free electrodes, the provided carbon structure results in good bonding with the active material and serves to bond the cathodes together without the need for conventional polymers or similar non- or low-conducting binders. As a result of being (non-conductive) binder-free, the carbon structure results in higher conductivity and higher cell performance. In this disclosure, a commercially available dry method AC binder-based electrode is used as a baseline for comparison.

Generally, the binder material is a non-conductive or low-conductivity material added to the electrode material to promote the mechanical integrity of the electrode layer and good adhesion to the current collector. The use of binder materials displaces other materials capable of storing and conducting energy, thus reducing the output of the energy storage cell in which they are used. One example of a binder is PVDF. Polyvinylidene fluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by polymerization of vinylidene difluoride. PVDF is typically used at the cathode. A common anode binder material is a styrene-butadiene copolymer.

Similarly, in Figures 3A, 3B and 3C, anode material 5 is shown. In Figure 3A, a SEM of hard carbon powder is shown. Figure 3B shows a prior art anode 8 made from a hard carbon powder and binder material. In Figure 3C, an aspect of an anode 8 according to the teachings herein is shown.

For explanatory purposes, the anode 8 presented herein consists of hard carbon (HC) as the active material. A slurry mixture for the anode was made including HC with a particle size (D50) of 2 μm and carbon nanotubes with carboxymethyl cellulose (CNT and CMC) serving as a binder material. In this example, the mass ratio of the three components was 98.33:0.67:1. After the slurry was prepared, the slurry was coated on a copper (Cu) foil substrate with a thickness of 10 μm. Then, the electrode was dried at 160 °C for 3 hours in an oven with air flow. An anode electrode sheet having a single-sided active material layer thickness of about 75 μm and a tap density of 1.0 g/cm 3 was fabricated. The porosity of the hard carbon anode was about 50%. The electrodes are then punched out of the electrode sheet to the desired dimensions of 4.6 cm x 4.6 cm (active area) for the anode and 4.5 cm x 4.5 cm for the cathode, then vacuum dried overnight at 120° C., where the final cell It was transported to a dry indoor environment prior to assembly. The electrodes were assembled in the configuration shown in FIG. 1 .

In the assembly of ESD 10, a lithium source 7 was incorporated into all anodes 8. In each embodiment, the lithium source 7 included an ultra-thin lithium film with holes therein. Holes were cut from a 20 μm Li-metal sheet (99.9% purity). The lithium source 7 provided a lithium source for pre-lithiation with various sizes to fabricate various LFP/AC hybrid composite cathode based LiB/LiC cells. Based on the HC anode first lithium intercalation specific capacity of about 372 mAh/g, the amount of u-Li with holes pre-loaded on the surface of the HC anode to completely pre-lithiate the HC is ~10 % (u-Li pre-loaded mass/anode active layer mass). In the cell design for LiC (0% LFP), it was determined that the anode should be pre-lithiated (with a lithium loading of about 10%) because the anode to cathode capacity ratio is about 0.14 (1:7). This LiC cell design enables LiC to have long cycles and high energy and power densities. However, when LFP is mixed in the hybrid composite binder-free cathode, the LFP will provide an additional source of lithium from the hybrid cathode when charged to the maximum operating voltage. In order to prevent the growth of lithium dendrites on the anode during charging of the cell, the actual mass load on the lithium source 7 (i.e. the ultra-thin lithium film with holes) disposed on the surface of the anode is the hybrid cathode The portion of the lithium source provided from the LFP in , should therefore be taken into account and should therefore be less than 10% of the weight of the anode active layer. It can be concluded that the decrease in lithium source 7 at the anode should be related to the increase in LFP at the cathode.

During cell assembly, loading of the lithium source 7 was performed in a dry indoor environment. An ultra-thin lithium film was placed using the application of pressure. In the example of the assembled ESD 10, the manner shown in FIG. 1 was followed. The anode was a double sided HC anode preloaded with a lithium source with holes between two single sided LFP/AC composite cathodes. The electrolyte used was 1M LiPF6 in a 1:1 weight mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC). All pouch cell assemblies were performed in a dry indoor environment (-40°C dew point). Figure 4 shows the charge/discharge profiles collected during initial testing.

4 shows initial test results of LiC with binder-free AC and HC electrodes under different current charging and discharging. The test conditions for these examples were 83.1% cathode porosity; It contained an anode porosity of 64.1%. The cell voltage range was 3.8 to 2.2V; The capacitance was 11.2F; The ESR was 0.127 Ω and the RC constant was 1.4 seconds. The specific energy and energy density based on the weight and volume of the cathode and anode active layers were measured as 36.6 Wh/kg and 20.1 Wh/L, respectively. The maximum specific power and power density based on the weight and volume of the cathode and anode active layers were measured as 69.7 kW/kg and 35.3 kW/L, respectively.

For this cell design, it is estimated from the results that the specific energy and energy density using a full-size multilayer 1000F LiC pouch cell can be 9 Wh/kg and 16 Wh/L, which is comparable to the competing 1000F LIC energy density (13.7 Wh/L ) is much higher than Also for this cell design, the ESR using a full-size multilayer 1000F LIC pouch cell can be 1.4mΩ, which is less than the ESR of a competing 1000F LIC cell (1.6 mΩ). Table 1 below provides a more detailed comparison to the prior art.

As can be seen from the comparison in Table 1, the ESR for the binder-free electrode based LiC was 30.6% less than the binder-based (ie prior art) control sample. Similarly, the RC constant for LiC using the binder-free electrode is only 1.4 seconds, whereas the binder-based LiC has a RC constant of 5.1 seconds. The maximum specific power and power density of LiC based on the binder-free electrode were 131.6% and 64.6% higher than the binder-based (ie prior art) control sample, respectively. 5A shows comparative ESR, and FIG. 5B is an exploded view of the curve presented in FIG. 5A. Aspects of the second embodiment tested are introduced in Figures 6A, 6B, 7A and 7B.

In a second embodiment, soft carbon and AC and LFP binder-free electrodes were used to study comparative performance. The ratio of SC:CNT:CMC is the same as that of the HC slurry, this time 20% LFP was added to the carbon backbone along with activated carbon (AC) to achieve a hybrid composite electrode. 6A and 6B are photomicrographs of soft carbon based electrodes. 7A and 7B are photomicrographs of AC and LFP binder-free electrodes. Assembly of the storage cell followed the same procedure as in the first embodiment outlined above. The physical aspects of the storage cell are described in Table 2.

In Table 2, control cells (ie, prior art soft carbon) are identified as A53 and A21. Storage cells fabricated without binder are identified as B43 and B44. The electrolyte used in the storage cell was A53: 1.0M LiPF ₆ in EC/DMC +1%VC; A21: 1.0M LiPF ₆ in EC/EMC/MB (20:20:60 by volume) +0.1M LiDFOB; B43: 1.0M LiFSI (20:46.7:23.3:10 by volume) +1% VC in EC/EMC/DEC/PC; and B44: 1.0M LiFSI (20:46.7:23.3:10 by volume) +1%VC in EC/EB/DEC/PC. The initial charge-discharge profiles for the storage cells were 0.25 and 12.5 mA/cm2 (10 and 500 mA). 8 shows the charge/discharge performance of four cells. These include initial constant current charge-discharge with ESR results.

9 shows the results for the low temperature test. As the A53 is not capable of operating at -45°C, the A53 was not included in the charge/discharge test. In the test, A21 showed the highest capacity retention rate at -45°C, about 40%. B44 showed the second highest capacity retention rate of about 30% at -45°C. Based on the cell design, the specific energy of the LIC is about 22.4 Wh/kg, and the 30% retention will be 6.7 Wh/kg, still holding half of the original 13 Wh/kg. LFP additives have been shown to lower capacity retention rates for low temperature tests. 10 provides comparative performance of soft carbon and hard carbon anodes. 10, it can be seen that B44 shows the best impedance compared to the other two electrolytes. For EIS, the hard carbon anode performed slightly better than the soft carbon anode for LIC, as shown by the smaller semicircle in the graph.

A third embodiment was directed to optimization of the electrolyte formulation for both high and low temperatures. In this embodiment, Y4 was the electrolyte control sample: 1.0M LiTFSI, EC/EMC/MB (20:20:60 by volume) +1% VC. Y5 and Y5.1 were BCN solvent-based electrolytes with LiTFSI salts with additives including VC, FEC, LiDFOB, LiBOB, LiDFOP, and LiNO ₃ . The electrolyte formulation for Y5 was 1.0M LiTFSI in BCN/EC/VC (80/10/10 by volume); The Y5.1 electrolyte formulation was 1.0M LiTFSI + 1% OS ₃ (commercially available additive) in BCN/EC/VC (80/10/10 by volume).

11 is a graph showing ESR performance as a function of temperature for three different types of electrolytes. Under low temperatures of -40°C, the binder-free LIC was shown to have an ESR increase of 3.4 Ω, whereas the conventional binder-based LIC had an ESR increase of 5.1 Ω. Using the Y5 electrolyte, the cell also passed the long-term cycle life test, and the results can be seen in FIG. 12 . In Figure 12, room temperature high C-rate cycle life tests for LIC using electrolytes: Y5; The voltage range is 3.8 to 2.2V, and the current is about 500 mA.

In a fourth embodiment, the performance of both high temperature (85°C) and low temperature (-55°C) electrolyte formulations was evaluated. Y7 was designated as a BCN solvent-based electrolyte with LiTFSI salts with co-solvents including GBL (gamma-butyrolactone), VC, FEC, and additives including LiDFOB, LiBOB, LiDFOP, LiNO ₃ , and the like. The Y7 electrolyte formulation is 1.0 M LiTFSI in BCN/GBL/VC/OS ₃ (74.5/12.5/10/3 by volume). 13 to 15 show the results of high-temperature cycling and direct charging of LICs using Y7 electrolyte. Y7 has the same low-temperature performance of -55°C as Y5 and Y5.1. 13 shows plots of cycle life performance of cells charged-discharged with Y7 electrolyte from 3.8V to 2.2V under a constant current of 500 mA, capacitance/ESR retention as a function of cycle number, and 85° C. cycle environment. 14 shows the discharge curves under various cycle numbers when the LIC is cycled at 85° C. based on the Y7 electrolyte. Fig. 15 shows a comparison of discharge curves after maintaining a constant voltage at 3.8 V (float test) under 85 DEG C before and after 330 hours.

A method of fabricating a storage cell according to the teachings herein is provided in FIG. 16 .

In some embodiments, the anode used is an electrode formed on both surfaces of the current collector including a sheet-like metal current collector having a double-coated conductive material and an electrode layer composed of the positive electrode active material and CNT. The negative electrode used in this LIC laminate cell is an electrode formed on both surfaces of the current collector including a sheet-shaped metal current collector having a double-sided coated conductive material and an electrode layer composed of a negative electrode active material and an additive.

The current collector used in the anode may be made of aluminum, stainless steel or other materials. In some of the examples presented, aluminum is used. The current collector used in the negative electrode may be made of stainless steel, copper, nickel, or the like. In some of the examples presented, copper is used. Generally, the thickness of the current collector at the positive and negative electrodes is in the range of about 5 to 50 μm. In the example presented, the range is 8 to 25 μm. These ranges ensure that the resulting positive and negative electrodes are of high strength and easy to apply the conductive coating material slurry. Conductive material coating accuracy, volumetric energy density and gravimetric energy density can be improved. Both surfaces of the positive and negative current collectors are coated with the carbon conductive coating slurry by a spray/coating method and dried, thereby obtaining current collectors having conductive layers for both the positive and negative electrodes. The carbon conductive coating thickness on one side of the current collector is 1 to 20 μm. In the example presented, the thickness ranged from 3 to 12 μm.

The positive and negative electrodes may be made of the electrode active materials described above. Specifically, anode/cathode active material powder, CNTs, and some solvent are dispersed into a blender/mixer to be mixed to obtain a wet slurry mixture. The percentage of additive added to the powder/slurry mixture is preferably between 2% and 12%. For anode manufacture, the slurry can be made without a binder. The slurry mixture is then coated onto a substrate that is a layer of the positive electrode active material. The thickness of the positive electrode active layer is between 30 and 250 μm, or in some embodiments between 50 and 200 μm. The binder-free electrode is then calendered by high temperature hot mill rollers to form the final anode for the LIC cell with the desired porosity and press density. The positive electrode active material, additives, and deionized water/IPA as a solvent are first mixed in a mixer for a sufficient time to form a uniform wet slurry. The slurry is then coated on both sides of the carbon conductive pre-coated current collector by an electrode coater with an attached drying oven to allow the coated electrode to dry. The gap of the coater can be adjusted according to the initial thickness requirements of electrode fabrication. The dried electrode is then pressed through a hot press calender to the desired active layer thickness to form the final anode for the LIC cell. The thickness of the positive electrode active layer based on the wet slurry manufacturing method on one side of the current collector is from 3 to 250 μm, and in some embodiments from 5 to 200 μm.

The anode active material, CNT/CMC additive, and deionized water as a solvent are first mixed in a mixer for a sufficient time to form a uniform wet slurry. The slurry is then coated on both sides of the carbon conductive pre-coated current collector by means of an electrode coater with an attached drying oven to allow the coated electrode to dry. The gap of the coater can be adjusted according to the initial thickness requirements of electrode fabrication. The dried electrode is then pressed through a hot press calender to the desired active layer thickness to form the final cathode for the LIC cell. The thickness of the negative electrode active layer based on the wet slurry manufacturing method on one side of the current collector is 3 to 200 μm, and in some embodiments, 5 to 160 μm is used.

In some embodiments of the LiC cells presented herein, the total thickness of the positive electrode including the thickness of the double-sided conductive material pre-coated current collector and the thickness of the double-sided active layer may be between 40 μm and 450 μm. In some embodiments of the LiC cells presented herein, the total thickness of the negative electrode including the thickness of the double-sided conductive material pre-coated current collector and the thickness of the double-sided active material layer may be between 20 μm and 350 μm. In some embodiments of the LiC cells presented herein, the thickness ratio of the total thickness of the positive active layer to the total thickness of the negative active layer can be from 1:2 to 3:1.

In general, the anode used is an electrode comprising a sheet-shaped metal current collector comprising a double-coated conductive material, an electrode layer composed of a cathode active material and CNT, and formed on both surfaces of the current collector. The negative electrode used in the LIC laminate cell of the present invention is an electrode formed on both surfaces of the current collector including a sheet-shaped metal current collector having a double-sided coated conductive material and an electrode layer composed of a negative electrode active material and an additive.

Generally, the Li source pre-loaded on the surface of the cathode is an ultra-thin Li film with holes. The ultra-thin Li film with holes is all prefabricated by a manufacturing method in which the top and bottom ultra-thin Li films with holes are laminated to the cathode, as described in detail in U.S. Patent Application No. 15/489,813, which is incorporated herein by reference in its entirety. applied to the surface of the negative electrode. The preparation can be carried out in a drying chamber with a dew point lower than -45 °C. The pressure of the lamination roll may be 40 kg/cm 2 to 400 kg/cm 2 . In some embodiments of the LiC cell presented herein, the mass per unit area of the ultra-thin Li film having holes loaded on one surface of the negative electrode is preferably 0.1 mg/cm 2 to 3 mg/cm 2 . The thickness of the ultra-thin Li film having holes pre-loaded on one surface of the cathode is preferably 2 to 50 μm. The length of the ultra-thin Li film having holes as a Li source loaded on the surface of the negative electrode may be 30 mm to 250 mm, and the width of the ultra-thin Li film having holes as a Li source loaded on the surface of the negative electrode may be 30 mm to 150 mm. can The area of the ultra-thin Li film having holes as a Li source loaded on the surface of the negative electrode may be about 25% to about 100% of the area of the negative electrode. In the ultra-thin Li film having holes as a Li source loaded on the surface of the negative electrode, an area size percentage of the holes may range from about 0.01% to about 75%. The mass ratio percentage of the ultra-thin Li film having holes pre-loaded on both surfaces of the negative electrode to the double-sided negative electrode active layer is preferably 7% to 14%. After all ultra-thin Li films having holes are pressed onto the cathode, a uniform thin-layer Li source position distribution can exist on the surface of the cathode.

In some embodiments of the LiC cells presented herein, electrodes comprising positive and negative electrodes with a lithium source pre-loaded on their surfaces are punched to a specified size by some additional current collector tabs before being laminated into a cell core unit. The size of the electrode determines the final size of the LIC cell as the outer vessel must match the size of the electrode. In some embodiments, the length and width of the negative electrode are between 0.5 mm and 5 mm greater than the length and width of the positive electrode for a LiC cell. In some embodiments of the LiC cells presented herein, the length of the punched positive and negative electrodes may be between 30 mm and 250 mm, and the width of the punched positive and negative electrodes may be between 30 mm and 150 mm.

Having introduced aspects of lithium ion capacitors, additional features and embodiments are now introduced.

In LiC, activated carbon can be used as the positive electrode (PE), while the negative electrode (NE) material can include various materials such as soft carbon, hard carbon, and graphite.

Cell components and design can be altered to improve the electrochemical performance of LiC. These are the selected active materials for PE, NE active materials and CNTs and the thickness/mass ratio of CNT, PE to NE active layer (without current collectors containing aluminum (Al) and copper (Cu)), PE to NE active layer. Consideration of capacity ratio may be included. Size design and number of layers of PE and NE, material type for separator, electrolyte composition, and NE pre-lithiation method. For PE, the active material can be binder-free activated carbon (AC). For NE, the active material can be hard carbon (HC), soft carbon (SC), graphite (G) and other carbon-based materials, and the network of CNTs with CMC can be used to create a strong carbon structure for the active material. can be relied on The material of the separator may be polypropylene (PP), polyethylene (PE) and cellulose or other similar materials.

In some embodiments of the LiC cells presented herein, the cell core unit is formed by laminating a positive electrode and a negative electrode through a separator in an outer container, eg, a laminated outer container. The negative electrode is pre-doped by pressing a lithium source comprising an ultra-thin Li film with holes on the surface of the negative electrode. "Pre-doping" roughly represents a phenomenon in which lithium ions enter the negative electrode active layer. The ultra-thin Li film with holes is a lithium ion source for pre-doping the negative electrode. The lithium source loading process ensures that the negative electrode has uniform lithium on its surface, so that the negative electrode is smoothly and uniformly pre-doped with lithium ions when the electrolyte is filled.

In some embodiments of the LiC cells presented herein, Cu and Al substrates are welded to nickel (Ni) coated copper (Cu), and aluminum (Al) current collector tabs, respectively. After the lamination and welding process, the electrode unit is housed in a container, and an aluminum laminate molding case suitable for the size of the electrode unit and a three-side heat sealing process are applied, for example. A desired amount of electrolyte is then filled into the LIC laminate cell to wet the cell to initiate the pre-doping process by intercalation of lithium into the negative electrode. After the cell has been soaked for a sufficient amount of time, a vacuum sealing process will be applied to the cell to remove excess gas trapped in the LIC laminate cell. As a result, this configuration can be achieved for LIC laminate cells.

The organic electrolyte may be a lithium ion battery electrolyte containing a Li salt. Pre-lithiation of the NE may be performed to allow the LIC to achieve the desired electrochemical performance. Some pre-lithiation methods, including electrochemical (EC) and external short circuit (ESC) methods, use a piece of Li metal as a sacrificial third electrode to pre-dope lithium into a graphite or HC electrode. In the EC pre-lithiation method, NE and Li metal are separated using a separator in a lithium salt-based organic electrolyte, and the pre-doping process can be performed by an electronic charger that controls the charging current or voltage.

The cathode active material must be able to reversibly adsorb or desorb lithium ions and anions from an electrolyte such as tetrafluoroborate. One example of such an active material is activated carbon powder. The specific surface area of activated carbon is 1,500 m2/g to 2,800 m2/g, preferably 1,600 m2/g to 2,400 m2/g. The diameter (D50) (average particle diameter) of the 50% cumulative volume of the activated carbon is preferably 2 μm to 10 μm. 3 μm to 8 μm is particularly preferable so that the energy density and power density of the LIC laminate cell can be further improved. Some other examples of such materials may be carbon black and activated carbon/carbon black/CNT composite materials (AC/CB/CNT).

The negative electrode active material should be able to reversibly intercalate and deintercalate lithium ions. Examples of such active materials include graphite-based composite particles, non-graphitizable carbon (hard carbon, (HC)) and graphitizable carbon (soft carbon, (SC)). In some embodiments, negative electrode active materials, HC and SC particles, are preferred because they can achieve higher performance in power performance and cycle stability than graphite materials. However, graphite materials can achieve higher energy performance for LICs because graphite has a higher specific capacity than HC and SC. in the range of 1.0 to 10 μm, to improve the power performance of the LIC cell; In some embodiments, it is preferred that HC and SC having a particle size that satisfies the diameter (D50) of 50% cumulative volume within the range of 2 to 6 μm is used as the negative electrode active material.

It should be noted that it is difficult to prepare HC and SC particles with a diameter (D50) of 50% cumulative volume of less than 10 μm. When the HC and SC particles have a diameter (D50) of 50% cumulative volume of 10 μm or more, an LIC cell with sufficiently small internal resistance is difficult to achieve. In some embodiments, the negative electrode active material has a specific surface area of 0.1 to 200 m 2 /g, more preferably 0.6 to 60 m 2 /g. The reason for setting this range is that if the specific surface area of the anode active material is less than 0.1 m 2 / g, the resistance of the LIC cell can be high, and if the specific surface area of the anode active material is 200 m 2 / g or more, the irreversible capacity of the LIC laminate cell during charging because it can be high.

In the ESC pre-lithiation method, the NE and the sacrificial Li metal third electrode are short-circuited through an external wire connection. However, it takes time for lithium to dissipate in a LIC laminate cell using conventional pre-lithiation methods and for the cell to fully lithiate to NE. The time required adds to the cost of this method. In addition, in the conventional pre-lithiation method, both PE and NE current collectors must be porous to create a path for lithium ions to migrate from the Li metal electrode through the LIC laminate cell, which also increases the manufacturing cost of the electrode.

Pre-lithiation techniques as disclosed herein address some of these problems. That is, loading an ultra-thin lithium film (abbreviated as u-Li) having holes on the NE surface can facilitate the cell manufacturing process and increase the pre-lithiation rate. Since Li metal can be directly coated on the carbon electrode, the current collector does not have to be porous to intercalate lithium ions into the NE. After cell impregnation with an electrolyte, the Li source at the NE surface reacts electrochemically with the carbon electrode active layer and intercalates into the NE.

Some advantages of the technology disclosed herein are now presented.

An advantage of the disclosed technology is a lithium ion capacitor (LIC) having excellent characteristics in lifetime, including cycle life and DC life, while maintaining high energy density and power density.

The advantages of the disclosed technology include a binder-free positive electrode, a surface pre-loaded negative electrode with a lithium source called ultra-thin lithium film (u-Li) with holes, a separator and an LIC with an organic solvent electrolyte solution with a lithium salt as the electrolyte. am.

An advantage of the disclosed technology is that the positive electrode active material is preferably activated carbon, carbon black, CNT, and activated carbon/carbon black/CNT mixture (AC/CB/CNT), and the negative electrode active material is hard carbon, soft carbon, graphite, CNT and Any possible mixture of the above materials is a preferred LiC cell.

An advantage of the disclosed technology is a LIC cell in which the positive electrode active material activated carbon (AC) has a surface area in the range of 1000 to 3000 m/g.

An advantage of the disclosed technology is a LIC cell in which the positive electrode active material activated carbon (AC) has a particle size of D50 ≤ 10 μm and the negative electrode active material has a particle size of D50 ≤ 10 μm.

An advantage of the disclosed technology is that no polymeric binder is used in the cathode material, increasing the conductivity of the electrode and improving the power performance of the LIC cell.

An advantage of the disclosed technology is a LIC cell in which the anode formulation can be tuned over a range of mass ratios between AC/CB and CNT/carbon backbone. and no or substantially no polymeric binders are used.

An advantage of the disclosed technology is that the LIC cells preferably have CNTs and carboxymethyl cellulose (CMC) as additives to make the negative electrode used in such LIC cells.

An advantage of the disclosed technology is an LIC cell in which the anode formulation can be tuned in a range of mass ratios between the anode active material and CNT/CMC.

An advantage of the disclosed technology is an LIC cell in which the total thickness of the anode including the thickness of the double-sided conductive material pre-coated aluminum (Al) foil and the thickness of the double-sided active material layer is between 40 μm and 450 μm.

An advantage of the disclosed technology is an LIC cell in which the total thickness of the negative electrode, including the thickness of the double-sided conductive material pre-coated copper (Cu) foil and the thickness of the double-sided active material layer, is between 20 μm and 350 μm.

An advantage of the disclosed technology is that the thickness ratio of the total thickness of the positive active layer to the total thickness of the negative active layer is preferably 1:2 to 3:1 in LIC cells.

An advantage of the disclosed technology is that LIC cells preferably have a positive electrode active layer to negative electrode active layer capacity ratio of 1:12 to 1:2.

An advantage of the disclosed technology is the LIC cell where the material of the separator is a cellulose, polypropylene (PP) and polyethylene (PE) based material.

An advantage of the disclosed technology is that the mass per unit area of the Li source comprising an ultra-thin lithium film with holes loaded on one surface of the negative electrode is preferably 0.1 mg/cm 2 to 3 mg/cm 2 in a LIC cell.

An advantage of the disclosed technology is that the thickness of the Li source ultra-thin film (u-Li) with holes, loaded on one surface of the cathode, is preferably 2 to 50 μm in LIC cells.

An advantage of the disclosed technology is a LIC cell in which the area of the ultra-thin Li film (u-Li) having holes as a Li source pre-loaded on one surface of the cathode is about 25% to about 100% of the cathode area.

An advantage of the disclosed technology is an LIC cell in which the hole size percentage ranges from 0.01% to about 75% in the ultra-thin Li film having the holes as the Li source pre-loaded on the surface of the cathode.

An advantage of the disclosed technology is an LIC cell in which the mass ratio percentage of Li source comprising an ultra-thin Li film with holes pre-loaded on one side of the negative electrode to the negative electrode active layer on one side is preferably between 7% and 14%.

An advantage of the disclosed technology is that the LIC cell is a laminate cell or a prismatic cell.

The advantages of the disclosed technology include two ultra-thin (less than 50 μm thick) single-sided anodes, one ultra-thin (less than 50 μm thick) double-sided electrode pre-loaded on the surface with an ultra-thin lithium film (u-Li) having holes, a separator , and an ultra-thin (less than 1 mm thick) LIC with an organic solvent electrolyte solution with a lithium salt as an electrolyte.

Advantages of the disclosed technology include unexpected solutions to the problem of creating lithium ion capacitor (LIC) cells with high energy and power densities, excellent cycling capability and DC lifetime. In the LIC cell system, which is a preferred embodiment of the present invention, the negative electrode is pre-doped with lithium ions by applying a lithium source comprising an ultra-thin Li film having holes to the surface of the negative electrode.

When pre-doped in this way, there are many factors that affect the electrochemical performance and capacity of a LIC cell. These factors include (1) materials used for the anode and cathode, including active materials and additives; (2) a method for producing positive electrodes and negative electrodes; (3) the thickness of the anode and cathode; (4) a thickness ratio of the total thickness of the positive active layer to the total thickness of the negative active layer; (5) the capacity ratio of the positive active layer to the negative active layer; (6) the material of the separator for the LIC cell; (7) mass per unit area of a Li source comprising an ultra-thin Li film with holes pre-loaded on the surface of the negative electrode; (8) the thickness of the Li source comprising an ultra-thin Li film with holes loaded on the surface of the cathode; (9) design of the area of the ultra-thin Li film with holes pre-loaded on the surface of the cathode and design of the area of holes in the ultra-thin Li film with holes; (10) Mass ratio percentage of a Li source comprising an ultra-thin Li film with holes pre-loaded on one side of the negative electrode to the negative electrode active layer on one side.

Advantages of the disclosed technology include a polymeric binder-free positive electrode, a polymeric binder-free negative electrode pre-loaded on the surface with a lithium source comprising an ultra-thin lithium film with holes, a separator, and an organic solvent electrolyte solution having a lithium salt as an electrolyte. It is a LiC cell containing

In some embodiments, the positive electrode active material is activated carbon, carbon black, CNT, or an activated carbon/carbon black/CNT blend (AC/CB/CNT). In the LIC cell of the present invention, the negative electrode active material is preferably graphite, hard carbon and soft carbon or any possible mixture of the above materials.

In some embodiments, the positive electrode active material activated carbon (AC) has a surface area in the range of 1000 to 3000 m 2 /g.

In some embodiments, the positive electrode active material activated carbon (AC) has a particle size of D50 ≤ 10 μm, and the negative electrode active material has a particle size of D50 ≤ 10 μm.

In some embodiments, the positive electrode formulation can be tuned in a range of mass ratios between AC/CB and CNTs, with a mass ratio between AC and CB ranging from 80:20 to 99:1.

In some embodiments, the total thickness of the positive electrode including the thickness of the double-sided conductive material pre-coated aluminum foil and the thickness of the double-sided active material layer is between 40 μm and 450 μm. In the LIC cell of the present invention, the total thickness of the negative electrode including the thickness of the double-sided conductive material pre-coated copper foil and the thickness of the double-sided active material layer is 20 μm to 350 μm. In the LIC cell of the present invention, the thickness ratio of the total thickness of the positive electrode active layer to the total thickness of the negative electrode active layer is preferably 1:2 to 3:1.

In some embodiments, it is preferred that the volume ratio of the positive active layer to the negative active layer is 1:12 to 1:2.

In some embodiments, the material of the separator is preferably a cellulosic, polypropylene (PP) and polyethylene (PE) based material in the LIC cell.

In some embodiments, the mass per unit area of the Li source including the ultra-thin Li film having holes loaded on one side of the negative electrode is preferably 0.1 mg/cm 2 to 3 mg/cm 2 .

In some embodiments, the thickness of the Li source comprising an ultra-thin Li film having holes pre-loaded on one surface of the negative electrode is preferably 2 to 50 μm.

In some embodiments, it is preferred that the area of the ultra-thin Li film having holes as the Li source pre-loaded on the surface of the negative electrode is about 25% to about 100% of the negative electrode area.

In some embodiments, it is preferred that the area size percentage range of the holes in the ultra-thin Li film having the holes as the Li source pre-loaded on the surface of the negative electrode ranges from about 0.01% to about 75%.

In some embodiments, the mass ratio percentage of the ultra-thin Li film with holes pre-loaded on both surfaces of the negative electrode to the double-sided negative electrode active layer is preferably 7% to 14%.

In some embodiments, two ultra-thin (less than 50 μm thick) single-sided anodes, one ultra-thin (less than 50 μm thick) double-sided cathode pre-loaded on the surface with an ultra-thin lithium film (u-Li) having holes, a separator and an organic solvent electrolyte solution having a lithium salt as an electrolyte.

In some embodiments, LIC cells with high energy density, high power density and long lifetime performance are provided.

In view of the above description, optimal dimensional relationships for parts of the present invention, including variations in size, material, shape, form, function and mode of operation, assembly and use, are considered to be readily apparent and self-evident to those skilled in the art. All relationships shown in the drawings and equivalent to those described in the specification are intended to be included in the present invention. Accordingly, the foregoing is only intended to explain the principles of the present invention. Furthermore, it is not desired to limit the invention to the precise construction and operation shown and described, as many modifications and variations will readily occur to those skilled in the art, and therefore all suitable modifications and equivalents may fall within the scope of the invention.

As used herein, certain abbreviations include dimethyl carbonate (DMC); lithium difluoro(oxalato)borate (LiDFOB); lithium bis(fluorosulfonyl)imide (LiFSI); propylene carbonate (PC); ethylene carbonate (EC); ethyl methyl carbonate (EMC); ethylene glycol monobutyl ether (EB); diethyl carbonate (DEC); vinylene carbonate (VC); boron nitride (BCN); lithium difluoro(oxalato)borate (LiDFOB); lithium bis(oxalato)borate (LiBOB); lithium difluoro bis(oxalato)phosphate (LiDFOP); terms such as lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

Various other components may be included and invoked to provide aspects of the teachings herein. For example, additional materials, combinations of materials, and/or omission of materials may be used to provide additional embodiments that are within the scope of the teachings herein. Various variations of the teachings herein may be practiced. In general, changes can be designed according to the needs of users, designers, manufacturers, or other similar stakeholders. Changes can be made to meet certain standards of performance that stakeholders deem important.

An appended claim or claim element is subject to 35 U.S.C. It should not be construed as invoking §112(f).

When introducing an element of the invention or its embodiment(s), the singular form is intended to mean that there is more than one component. Similarly, the adjective "another" used to introduce an element is intended to mean one or more elements. The terms "comprising" and "having" are intended to be inclusive, so that there may be additional elements other than those listed. As used herein, the term "exemplary" is not intended to mean the best example. Rather, “exemplary” refers to an example of an embodiment that is one of many possible embodiments.

Although the invention has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many changes will be understood by those skilled in the art to adapt a particular tool, situation, or material to the teachings of the present invention without departing from its essential scope. Accordingly, the invention is not limited to the particular embodiment disclosed as the best mode contemplated for carrying out the invention, but the invention will include all embodiments falling within the scope of the appended claims.

Claims (44)

As a lithium ion capacitor device,
an anode comprising a network of carbon substantially free of binder material;
a negative electrode comprising a network of carbon substantially free of binder material, separated from the positive electrode by a separator; and
a lithium film disposed on the negative electrode to provide pre-lithiation of the capacitor;
Including; At least one of the anode and cathode,
a network of high-aspect-ratio carbon elements defining voids within the network;
a plurality of electrode active material particles disposed in the voids in the network and entangled in the network;
Including, device. The apparatus of claim 1 , wherein the high-aspect-ratio carbon elements each include elements having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is at least 10 times the length ratio of the minor dimension. . 3. The method of claim 1 or 2, wherein the high aspect ratio carbon elements each include elements having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is at least the length ratio of the minor dimension. Device, which is 100 times. 4. The method of any one of claims 1 to 3, wherein the high-aspect-ratio carbon element comprises elements each having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is of the minor dimension. at least 1,000 times the length ratio. 5. The method of any one of claims 1 to 4, wherein the high aspect ratio carbon element comprises elements each having two major dimensions and one minor dimension, wherein the length ratio of each major dimension is of the minor dimension. at least 10,0000 times the length ratio. 6. The method of any one of claims 1 to 5, wherein the high-aspect-ratio carbon element comprises elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being the length ratio of each minor dimension. at least 10 times the length ratio of 7. The method of any one of claims 1 to 6, wherein the high aspect ratio carbon element comprises elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being the length ratio of each minor dimension. at least 100 times the length ratio of 8. The method of any one of claims 1 to 7, wherein the high-aspect-ratio carbon element comprises elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being the length ratio of each minor dimension. at least 1,000 times the length ratio of 9. The method of any one of claims 1 to 8, wherein the high-aspect-ratio carbon element comprises elements each having one major dimension and two minor dimensions, the length ratio of each major dimension being the length ratio of each minor dimension. at least 10,000 times the length ratio of 10. The device of any one of claims 1 to 9, wherein the high aspect ratio carbon element comprises a carbon nanotube or a carbon nanotube bundle. 11. The device of any preceding claim, wherein the high aspect ratio carbon element comprises graphene flakes. 12. A device according to any one of claims 1 to 11, wherein the electrode active layer contains less than 10% by weight of a polymeric binder disposed in the void space. 13. A device according to any one of claims 1 to 12, wherein the electrode active layer contains less than 1% by weight of a polymeric binder disposed in the void space. 14. A device according to any one of claims 1 to 13, wherein the electrode active layer contains less than 1% by weight of a polymeric binder disposed in the void space. 15. A device according to any one of claims 1 to 14, wherein the electrode active layer is substantially free of polymeric material other than a surface treatment. 16. A device according to any one of claims 1 to 15, wherein the electrode active layer is substantially free of polymeric material. 17. The device of any one of claims 1-16, wherein the network is at least 90% carbon by weight. 18. The device of any one of claims 1-17, wherein the network is at least 95 weight percent carbon. 19. The device of any one of claims 1-18, wherein the network is at least 99 weight percent carbon. 20. The device of any one of claims 1-19, wherein the network is at least 99.9 weight percent carbon. 21. The device of any one of claims 1 to 20, wherein the network comprises an electrically interconnected network of carbon elements exhibiting connectivity above the osmotic threshold. 22. The device of any preceding claim, wherein the network defines one or more highly electrically conductive pathways. 30. The device of claim 29, wherein the path has a length greater than 100 [mu]m. 30. The device of claim 29, wherein the path has a length greater than 1,000 [mu]m. 30. The device of claim 29, wherein the path has a length greater than 10,000 [mu]m. 26. The method of any one of claims 1 to 25, wherein the network comprises one or more structures formed of the carbon elements, the structures comprising an overall length that is at least 10 times the length of the largest dimension of the carbon elements. Device. 27. The device of any one of claims 1 to 26, wherein the network comprises one or more structures formed of the carbon elements, the structures comprising an overall length that is at least 100 times the maximum dimension length of the carbon elements. . 28. The device of any one of claims 1-27, wherein the network comprises one or more structures formed of the carbon elements, the structures comprising an overall length that is at least 1,000 times the maximum dimension length of the carbon elements. 29. The method of any one of claims 1 to 28, wherein the positive electrode comprises at least one from the list consisting of activated carbon, carbon black, graphite, hard carbon, soft carbon, nanofoam carbon, high aspect ratio carbon, and mixtures thereof. A device comprising an electrode active material comprising: (omission) 30. The device according to any one of claims 1 to 29, wherein the anode comprises an electrode active material comprising activated carbon (AC) having a specific surface area in the range of 1000 to 3000 m2/g. 32. The device of any one of claims 1 to 31, wherein the anode comprises an electrode active material comprising activated carbon (AC) having a particle size of D50 ≤ 10 μm. 33. The device according to any one of claims 1 to 32, wherein the negative electrode comprises an electrode active material having a particle size of D50 ≤ 10 μm. 34. The method of any one of claims 1 to 33, wherein the positive electrode comprises an electrode active material comprising activated carbon (AC), carbon black (BC) and high-aspect-ratio carbon, wherein the active material and the high-aspect-ratio carbon wherein the mass ratio between carbons is in the range of 80:20 to 99:1. 35. The device of any preceding claim, wherein the combined total thickness of the positive electrode and the lithium film is between 40 μm and 450 μm. 36. The device of any one of claims 1 to 35, wherein the total thickness of the cathode is between 20 μm and 350 μm. 37. The device of any one of claims 1 to 36, wherein the thickness ratio of the total thickness of the positive active layer to the total thickness of the negative active layer is in the range of 1:2 to 3:1. 38. The device of any one of claims 1 to 37, wherein the volume ratio of the positive electrode active layer to the negative electrode active layer is in the range of 1:12 to 1:2. 39. The device of any one of claims 1 to 38, wherein the lithium film comprises an ultra-thin lithium film comprising holes. 40. The device according to any one of claims 1 to 39, wherein the mass per unit area of the Li source on the side of the negative electrode active layer is in the range of 0.1 mg/cm2 to 3 mg/cm2. 41. The device according to any one of claims 1 to 40, wherein the thickness of the Li source at the side of the negative active electrode layer is in the range of 2 to 50 [mu]m. 42. The device of any preceding claim, wherein the surface area of the lithium film is from about 25% to about 100% of the surface area of the side surface of the negative electrode.
[Claim 42]
42. The device of any one of claims 1-41, wherein the lithium film comprises holes, and the area size percentage of the holes ranges from about 0.01% to about 75% of the total area of the film. As a method for manufacturing a lithium ion capacitor,
providing an energy storage cell,
selecting an anode comprising a carbon network substantially free of binder material;
selecting a negative electrode comprising a carbon network substantially free of binder material, separated from the positive electrode by a separator; and
placing a lithium film on the negative electrode to provide pre-lithiation of the capacitor;
providing the energy storage cell by;
sealing the energy storage cell and electrolyte in a housing to provide the capacitor. 44. The method of claim 43, wherein the lithium ion capacitor comprises the device of any one of claims 1-42.