Silicon anode electrode with active material particles coated with solid electrolyte for solid state battery cells

Abstract

An anode electrode for a battery cell includes an anode active material layer. The anode active material layer includes an anode active material and an overcoat layer covering at least a portion of an outer surface of particles of the anode active material layer. The overcoat includes a solid electrolyte and a fibril binder.

Description

Technical Field

[0001] The present disclosure relates to battery pack cells, and more particularly to a silicon anode electrode for a solid-state battery pack cell having active material particles coated with a solid electrolyte. Background Art

[0002] The information provided in this section is intended to generally introduce the background of the present disclosure. To the extent that the work currently attributed to the inventors is described in this section, and aspects of the specification that may not otherwise be determined to be prior art at the time of filing, are not expressly or impliedly admitted to be prior art against the present disclosure.

[0003] The present disclosure relates to battery pack cells, and more particularly to a silicon anode electrode for a solid-state battery pack cell having active material particles coated with a solid electrolyte.

[0004] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid vehicles, and / or fuel cell vehicles, include one or more electric motors and a battery pack system including one or more battery pack cells, modules, and / or battery packs. A power control system is used to control the charging and / or discharging of the battery pack system during charging and / or driving.

[0005] A battery pack cell includes a cathode electrode, an anode electrode, and a separator. The cathode electrode includes a cathode active material layer disposed on a cathode current collector. The anode electrode includes an anode active material layer disposed on an anode current collector. Summary of the Invention

[0006] An anode electrode for a battery pack cell includes an anode active material layer. The anode active material layer includes an anode active material and an outer coating covering at least a portion of the outer surface of the particles of the anode active material layer. The outer coating includes a solid electrolyte and a fibrillating binder.

[0007] In other features, the anode active material layer is disposed on an anode current collector. The fibrillating binder includes polytetrafluoroethylene (PTFE). The anode active material is selected from silicon, silicon alloys, and silicon / silicon oxides. The softening point of the fibrillating binder is from 270 °C to 380 °C. The molecular weight of the fibrillating binder is from 105 g / mol to 109 g / mol.

[0008] In other features, the loading of the anode active material layer is from 4 mAh / cm 2 to 30 mAh / cm 2The thickness of the anode active material layer is from 10 μm to 200 μm. The solid electrolyte is selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes. The solid electrolyte includes a sulfide solid electrolyte. The sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides. The anode active material accounts for 70 wt% to 98 wt% of the anode active material layer, the solid electrolyte accounts for 2 wt% to 30 wt% of the anode active material layer, and the fibrillar binder accounts for 0.1 wt% to 5 wt% of the anode active material layer.

[0009] The anode electrode for a battery pack cell includes an anode current collector and an anode active material layer disposed on the anode current collector. The anode active material layer contains an anode active material selected from silicon, silicon alloys, and silicon / silicon oxides. An outer coating covers at least a portion of the outer surface of the particles of the anode active material layer. The outer coating contains a solid electrolyte selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes. The fibrillar binder includes polytetrafluoroethylene (PTFE).

[0010] Among other features, the loading of the anode active material layer is 4 mAh / cm 2 to 30 mAh / cm 2 The thickness of the anode active material layer is from 10 μm to 200 μm. The solid electrolyte includes a sulfide solid electrolyte. The sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides. The anode active material accounts for 70 wt% to 98 wt% of the anode active material layer, the solid electrolyte accounts for 2 wt% to 30 wt% of the anode active material layer, and the fibrillar binder accounts for 0.1 wt% to 5 wt% of the anode active material layer.

[0011] A method of manufacturing an anode electrode for a battery pack cell includes mixing and grinding a premix that includes particles of an anode active material selected from silicon, silicon alloys, and silicon / silicon oxides and particles of a solid electrolyte selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes. The particles of the solid electrolyte at least partially coat the particles of the anode active material. The method includes adding a fibrillar binder to the premix; mixing and shearing the premix to produce fibrillated fibrils bound together and produce a mixture for the anode active material layer; and one of: pressing the mixture to produce a free-standing anode active material layer, and casting the mixture onto an anode current collector to form the anode active material layer of the anode electrode.

[0012] Among other features, the solid electrolyte includes a sulfide solid electrolyte. The sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides. The anode active material accounts for 70 wt% to 98 wt% of the anode active material layer, the solid electrolyte accounts for 2 wt% to 30 wt% of the anode active material layer, and the fibrillar binder accounts for 0.1 wt% to 5 wt% of the anode active material layer.

[0013] The present invention provides the following solutions:

[0014] Solution 1. An anode electrode for a battery pack cell, comprising:

[0015] An anode active material layer, comprising:

[0016] An anode active material;

[0017] An outer coating that covers at least a portion of the outer surface of the particles of the anode active material layer,

[0018] wherein the outer coating contains a solid electrolyte; and

[0019] A fibrillar binder.

[0020] Solution 2. The anode electrode according to Solution 1, wherein the anode active material layer is disposed on an anode current collector.

[0021] Solution 3. The anode electrode according to Solution 1, wherein the fibrillar binder includes polytetrafluoroethylene (PTFE).

[0022] Solution 4. The anode electrode according to Solution 1, wherein the anode active material is selected from silicon, silicon alloys, and silicon / silicon oxides.

[0023] Solution 5. The anode electrode according to Solution 1, wherein the softening point of the fibrillar binder is 270 °C to 380 °C.

[0024] Solution 6. The anode electrode according to Solution 1, wherein the molecular weight of the fibrillar binder is 105 g / mol to 109 g / mol.

[0025] Solution 7. The anode electrode according to Solution 1, wherein the loading of the anode active material layer is 4 mAh / cm 2 to 30 mAh / cm 2 .

[0026] Solution 8. The anode electrode according to Solution 1, wherein the thickness of the anode active material layer is 10 μm to 200 μm.

[0027] Aspect 9. The anode electrode according to Aspect 1, wherein the solid electrolyte is selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes.

[0028] Aspect 10. The anode electrode according to Aspect 1, wherein the solid electrolyte comprises a sulfide solid electrolyte.

[0029] Aspect 11. The anode electrode according to Aspect 10, wherein the sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides.

[0030] Aspect 12. The anode electrode according to Aspect 1, wherein the anode active material accounts for 70 wt% to 98 wt% of the anode active material layer, the solid electrolyte accounts for 2 wt% to 30 wt% of the anode active material layer, and the fibrillar binder accounts for 0.1 wt% to 5 wt% of the anode active material layer.

[0031] Aspect 13. An anode electrode for a battery pack cell, comprising:

[0032] an anode current collector; and

[0033] an anode active material layer disposed on the anode current collector, wherein the anode active material layer comprises:

[0034] an anode active material selected from silicon, silicon alloys, and silicon / silicon oxides;

[0035] an outer coating covering at least a portion of the outer surface of the particles of the anode active material layer,

[0036] wherein the outer coating comprises a solid electrolyte selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes; and

[0037] a fibrillar binder comprising polytetrafluoroethylene (PTFE).

[0038] Aspect 14. The anode electrode according to Aspect 13, wherein the loading of the anode active material layer is 4 mAh / cm 2 to 30 mAh / cm 2 .

[0039] Aspect 15. The anode electrode according to Aspect 13, wherein the thickness of the anode active material layer is 10 μm to 200 μm.

[0040] Aspect 16. The anode electrode according to Aspect 13, wherein:

[0041] the solid electrolyte comprises a sulfide solid electrolyte, and

[0042] The sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides.

[0043] Aspect 17. The anode electrode according to Aspect 13, wherein the anode active material accounts for 70% to 98% by weight of the anode active material layer, the solid electrolyte accounts for 2% to 30% by weight of the anode active material layer, and the fibril binder accounts for 0.1% to 5% by weight of the anode active material layer.

[0044] Aspect 18. A method for manufacturing an anode electrode for a battery pack cell, comprising:

[0045] Mixing and grinding a premix, the premix comprising:

[0046] Particles of an anode active material selected from silicon, silicon alloys, and silicon / silicon oxides, and

[0047] Particles of a solid electrolyte selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes;

[0048] wherein the particles of the solid electrolyte at least partially coat the particles of the anode active material;

[0049] Adding a fibril binder to the premix;

[0050] Mixing and shearing the premix to produce fibrillated bound fibrils and produce a mixture for the anode active material layer; and

[0051] One of the following:

[0052] Pressing the mixture to produce a self-standing anode active material layer, and

[0053] Casting the mixture onto an anode current collector to form the anode active material layer of the anode electrode.

[0054] Aspect 19. The method according to Aspect 18, wherein:

[0055] The solid electrolyte comprises a sulfide solid electrolyte, and

[0056] The sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides.

[0057] Scheme 20. The method according to Scheme 18, wherein the anode active material accounts for 70% to 98% by weight of the anode active material layer, the solid electrolyte accounts for 2% to 30% by weight of the anode active material layer, and the fibril binder accounts for 0.1% to 5% by weight of the anode active material layer.

[0058] From the detailed description, the claims, and the drawings, further applicable fields of the present disclosure will become apparent. The detailed description and specific examples are only intended to illustrate and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The present disclosure will be more fully understood through the detailed description and the drawings, wherein:

[0060] Figure 1 is a side cross-sectional view of an example of a solid-state battery pack cell including an anode electrode, a cathode electrode, and a separator according to the present disclosure;

[0061] Figure 2 is a side cross-sectional view of an example of a cathode electrode according to the present disclosure;

[0062] Figure 3A is a side cross-sectional view of an example of an anode electrode before formation according to the present disclosure;

[0063] Figure 3B is according to the present disclosure Figure 3A of the side cross-sectional view of the anode electrode after formation;

[0064] Figure 3C and Figure 3D are side cross-sectional views showing different examples of the morphology of anode active material particles according to the present disclosure;

[0065] Figure 4 is a flowchart of an example of a method for manufacturing a cathode electrode according to the present disclosure;

[0066] Figure 5 is a scanning electron microscope image of an example of an anode electrode including a silicon active material and a fibril binder;

[0067] Figure 6 is a scanning electron microscope image of an example of an anode electrode including a silicon active material coated with a sulfide solid electrolyte and a fibril binder according to the present disclosure;

[0068] Figure 7 is a graph showing the change of voltage with specific capacity of a conventional anode electrode and an anode electrode including a silicon active material coated with a solid electrolyte and a fibril binder according to the present disclosure; and

[0069] Figure 8It is a graph showing the change in capacity of a conventional anode electrode and an anode electrode according to the present disclosure including a silicon active material coated with a solid electrolyte and a fibril binder over cycles.

[0070] In the drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Description

[0071] Although the battery cells of the present disclosure are shown in the context of an electric vehicle, the battery cells may be used in stationary applications and / or other applications.

[0072] A dry manufacturing method can be used to manufacture the anode electrode. Different from the wet method, the dry method does not use solvents and does not require manufacturing equipment or floor space for the drying stage. For example, a silicon anode electrode manufactured using the dry method includes an anode active material layer disposed on an anode current collector. The anode active material includes silicon particles, which are mixed / sheared with a fibril binder (such as PTFE), cast onto the anode current collector, and calendared (or manufactured as a self-standing film on a removable substrate and laminated to the anode current collector). However, using a PTFE binder reduces the performance of the anode electrode due to side reactions. Li x The side reaction between the Li

[0073] 2nLixSi + x[-CF2-] n (PTFE) → 2nx LiF + 2nSi + nx C (amorphous)

[0074] More specifically, the side reaction between the Li x Si compound and the PTFE binder consumes the active lithium in the anode electrode, which reduces the performance of the battery cells. The side reaction does not occur only at the contact points between the Li x Si compound and the PTFE binder. Due to electrode swelling, the PTFE binder is completely reduced within the solid-state battery cells. It can be understood that the side reaction should be significantly reduced or prevented to achieve a dry film silicon anode electrode.

[0075] The anode electrode according to the present disclosure is prepared by coating particles of an anode active material (e.g., silicon) with a solid electrolyte (e.g., a sulfide solid electrolyte). For example, the particles of the anode active material and the particles of the solid electrolyte are pre-mixed and ground to coat the active material with the solid electrolyte. Then, the coated anode active material is mixed / sheared with a fibrillating binder (e.g., PTFE) to produce fibrils. The mixture is pressed and calendared to form an anode active material layer as a flexible continuous dry film (or directly cast onto the anode current collector). If cast as a self-standing film, the anode active material layer is laminated onto the anode current collector.

[0076] The solid electrolyte coating inhibits the Li x Si / PTFE side reaction and increases the favorable lithium ion transport in the anode electrode. Thus, the anode electrode has a high initial Coulombic efficiency, a high initial discharge capacity, and stable battery cycling.

[0077] Now referring to Figure 1 , the battery pack cell 10 includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 arranged in a battery cell stack 12 in a predetermined order, where C, S, and A are integers greater than zero. The battery cell stack 12 is arranged in a housing 50. The C cathode electrodes 20-1, 20-2,... and 20-C include cathode active material layers 24 arranged on one or both sides of a cathode current collector 26.

[0078] The A anode electrodes 40-1, 40-2,... and 40-A include anode active material layers 42 arranged on one or both sides of an anode current collector 46. During charge / discharge, the A anode electrodes 40 and the C cathode electrodes 20 exchange lithium ions.

[0079] In some instances, the cathode current collector 26 and / or the anode current collector 46 includes a metal foil, a metal mesh, a perforated metal, a three-dimensional (3D) metal foam, and / or an expanded metal. In some instances, the current collector is made of one or more materials selected from copper, stainless steel, brass, bronze, zinc, aluminum, and / or their alloys. The external tabs 28 and 48 are respectively connected to the current collectors of the cathode electrode and the anode electrode, and may be arranged on the same side or different sides of the battery pack cell stack 12. The external tabs 28 and 48 are connected to the terminals of the battery pack.

[0080] Now referring to Figure 2, which more particularly shows one of the C cathode electrodes 20 before formation. The cathode active material layer 24 of the C cathode electrodes 20 includes a mixture of a cathode active material 52 and a sulfide solid electrolyte 54. In some instances, the cathode active material layer 24 further includes a fibrillar binder and / or a conductive filler (both not shown).

[0081] Now referring to Figure 3A , which more particularly shows one of the A anode electrodes 40 before formation (lithiation of silicon). The anode active material layer 42 of the anode electrode 40 includes an anode active material 62. The anode active material 62 is selected from silicon, silicon alloys (e.g., lithium alloyed metals such as aluminum (Al), tin (Sn), magnesium (Mg), etc.), and silicon / silicon oxide (Si / SiO x ). The particles of the anode active material 62 are mixed and ground with a solid electrolyte to partially coat or completely coat the outer surface of the anode active material particles with a solid electrolyte 64 (e.g., a sulfide). The coated anode active material is mixed / sheared with a fibrillar binder 66 and then calendared.

[0082] In some instances, the fibrillar binder includes polytetrafluoroethylene (PTFE). In some instances, the fibrillar binder has a particle size of 100 μm to 800 μm. In some instances, the fibrillar binder has a particle size of 300 μm to 700 μm. In some instances, the weight ratio of the fibrillar binder to the anode active material layer is 0.01:100 to 20:100 (e.g., 0.05:100). In some instances, the softening point of the fibrillar binder is 270 °C to 380 °C. In some instances, the molecular weight of the fibrillar binder is 105 g / mol to 109 g / mol. In some instances, water is completely removed before use.

[0083] In Figure 3B , one of the A anode electrodes 40 after formation is more particularly shown. After formation, the A anode electrodes 40 include lithiated anode active material (e.g., Li x Si) merged together under pressure, as shown at 68. Most of the fibrils of the fibrillar binder 66 are encapsulated within the solid electrolyte 64.

[0084] In Figure 3C , the solid electrolyte 64 may have a continuous morphology on the outer surface of the particles of the anode active material 62. In Figure 3D , the solid electrolyte 64 may have a discontinuous morphology on the outer surface of the particles of the anode active material 62. It will be appreciated that since the fibrillar binder tends to adhere to the solid electrolyte 64, the coating does not need to completely cover the anode active material to significantly reduce side reactions.

[0085] The dry film method described herein eliminates the use of organic solvents and simplifies the electrode manufacturing method by removing the conventional drying step. The solvent-free dry film method avoids the influence of solvents on lithium ion conduction in solid electrolytes and achieves good electrochemical performance of high-energy anode electrodes.

[0086] In some examples, the anode active material layer 42 comprises an anode active material, a sulfide solid electrolyte (coating the anode active material), and a fibrillar binder. In some examples, the anode active material accounts for 70 wt% to 98 wt% of the anode active material layer, the solid electrolyte accounts for 2 wt% to 30 wt% of the anode active material layer, and the fibrillar binder accounts for 0.1 wt% to 5 wt% of the anode active material layer (e.g., a ratio of 70:29:1 wt%). In some examples, the loading of the anode active material layer is 4 mAh / cm 2 to 30 mAh / cm 2 . In some examples, the thickness of the anode active material layer is 10 μm to 200 μm.

[0087] In some examples, the solid electrolyte has low electronic conductivity and high lithium ion conductivity to prevent side reactions. The solid electrolyte provides a rough / deformable surface to promote fibrillization of the binder. The solid electrolyte coating blocks the side reaction between Li x Si and PTFE by encapsulating PTFE within the solid electrolyte. The solid electrolyte constructs favorable lithium ion transport within lithiated silicon (Li x Si). The particles of the anode active material provide high capacity and expand to form a dense anode electrode. The fibrils of the binder adhere the particles together like a "spider web" to form a dry film.

[0088] Now referring to Figure 4 , a flowchart of an example of a method for manufacturing a cathode electrode is shown. At 110, particles of an anode active material (e.g., silicon) and particles of a solid electrolyte (e.g., a sulfide solid electrolyte) are premixed and ground to coat the particles of the active material. At 114, a fibrillar binder such as PTFE is added to the mixture. At 118, the mixture is mixed and sheared to fibrillize the fibrillar binder and generate fibrils. At 122, the mixture forming the anode active material layer is pressed and / or heated to form a dry film. At 126, the anode active material layer is laminated onto an anode current collector. Alternatively, the active material layer can be directly cast onto the anode current collector and steps 122 and 126 can be omitted.

[0089] Now referring to Figure 5 and Figure 6 , scanning electron microscope images of a conventional anode electrode (at 310) and an anode electrode according to the present disclosure (at 314) are shown. At Figure 5Among them, the traditional anode electrode includes 99 wt% silicon active material (not coated with a sulfide solid electrolyte) and 1 wt% fibril binder. Since the outer surface of the silicon particles is relatively smooth and hard, compared with Figure 6 less fibrillization of the binder occurs.

[0090] In Figure 6 an anode electrode including a silicon active material (e.g., 70 wt%) is coated with a sulfide solid electrolyte (e.g., 29 wt%) and mixed / sheared with a fibril binder (e.g., 1 wt%). The silicon particles are partially or fully coated with a solid electrolyte (such as a sulfide solid electrolyte). As can be seen in Figure 6 the sulfide solid electrolyte with a deformable surface provides more adhesion sites for constructing more fibrils in the dry film electrode. The PTFE fibrils are interconnected between the solid electrolytes to form a dry film.

[0091] Now referring to Figure 7 and Figure 8 the performance of the anode electrode including a silicon active material coated with a sulfide solid electrolyte and a fibril binder is superior to that of the traditional anode electrode. In Figure 7 the first cycle performance (e.g., at 0.1 C and room temperature) of the coated anode electrode (at 314) is compared with that of the traditional anode (at 310). In Figure 8 the capacity is shown to vary with cycling.

[0092] In some instances, the solid electrolyte is selected from sulfide-based solid electrolytes, halide-based solid electrolytes, hydride-based solid electrolytes, and other solid electrolytes with low grain boundary resistance. In some instances, the sulfide solid electrolyte is selected from pseudo-binary sulfides, pseudo-tertiary sulfides, and pseudo-quaternary sulfides. Examples of halide-based solid electrolytes include Li3YCl6, Li3InCl6, Li3YBr6, Lil, Li2CdCl4, Li2MgCl4, Li2CdI4, Li2ZnI4, Li3OCl, and combinations thereof. Examples of hydride-based solid electrolytes include LiBH4, LiBH4-LiX (where X = chlorine (Cl), bromine (Br), or iodine (I)), LiNH2, Li2NH, LiBH4-LiNH2, Li3AlH6, and combinations thereof.

[0093] Examples of pseudo-binary sulfides include the Li2S-P2S5 system (Li3PS4, Li7P3S 11 and Li 9.6 P3S 12) Li2S - SnS2 system (Li4SnS4), Li2S - SiS2 system, Li2S - GeS2 system, Li2S - B2S3 system, Li2S - Ga2S3 system, Li2S - P2S3 system, and Li2S - Al2S3 system. Examples of pseudo - ternary sulfides include Li2O - Li2S - P2S5 system, Li2S - P2S5 - P2O5 system, Li2S - P2S5 - GeS2 system (Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 ), Li2S - P2S5 - LiX (X = F, Cl, Br, I) system (Li6PS5Br, Li6PS5Cl, Li7P2S8I and Li4PS4I), Li2S - As2S5 - SnS2 system (Li 3.833 Sn 0.833 As 0.166 S4), Li2S - P2S5 - Al2S3 system, Li2S - LiX - SiS2 (X = F, Cl, Br, I) system, 0.4LiI·0.6Li4SnS4, Li 11 Si2PS 12 and their combinations.

[0094] Examples of pseudo - quaternary sulfides include Li2O - Li2S - P2S5 - P2O5 system, Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li7P 2.9 Mn 0.1 S 10.7 I 0.3 and Li 10.35 [Sn 0.27 Si 1.08 P 1.65 S 12 . Examples of halide - based solid electrolytes include Li3YCl6, Li3InCl6, Li3YBr6, LiI, Li2CdCl4, Li2MgCl4, Li2CdI4, Li2ZnI4, Li3Ocl and their combinations.

[0095] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while the disclosure includes specific examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be implemented in a different order (or concurrently) without altering the principles of the disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of the features described with respect to any one embodiment of the disclosure can be implemented in or combined with the features of any other embodiment, even if not explicitly described in combination. In other words, the described embodiments are not mutually exclusive, and a permutation of one or more of the embodiments is still within the scope of the disclosure.

[0096] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless explicitly described as "direct," when the relationship between a first element and a second element is described in the foregoing disclosure, the relationship can be a direct relationship in which no other intervening elements exist between the first and second elements, or an indirect relationship in which one or more intervening elements exist between the first and second elements (spatially or functionally). The phrase "at least one of A, B, and C" as used herein should be construed to mean a logical (A or B or C) using a non-exclusive logical OR and should not be construed to mean "at least one of A, at least one of B, and at least one of C."

[0097] In the drawings, the direction of an arrow as shown by the arrowhead generally demonstrates the flow of information (such as data or instructions) associated with the illustration. For example, when element A and element B exchange various information but the information transmitted from element A to element B is associated with the illustration, the arrow can point from element A to element B. Such a unidirectional arrow does not mean that no other information is transmitted from element B to element A. Further, for the information transmitted from element A to element B, element B can send a request for that information or receive an acknowledgement.

Claims

1. An anode electrode for a battery cell of a battery pack, comprising: An anode active material layer, comprising: An anode active material; An outer coating covering at least a part of the outer surface of the particles of the anode active material layer, wherein the outer coating contains a solid electrolyte; and A fibrillar binder.

2. The anode electrode according to claim 1, wherein the anode active material layer is disposed on an anode current collector.

3. The anode electrode according to claim 1, wherein the fibrillar binder comprises polytetrafluoroethylene (PTFE).

4. The anode electrode according to claim 1, wherein the anode active material is selected from silicon, silicon alloy, and silicon / silicon oxide.

5. The anode electrode according to claim 1, wherein the softening point of the fibrillar binder is 270 °C to 380 °C.

6. The anode electrode according to claim 1, wherein the molecular weight of the fibrillar binder is 105 g / mol to 109 g / mol.

7. The anode electrode according to claim 1, wherein the loading of the anode active material layer is 4 mAh / cm 2 to 30 mAh / cm 2 .

8. The anode electrode according to claim 1, wherein the thickness of the anode active material layer is 10 μm to 200 μm.

9. The anode electrode according to claim 1, wherein the solid electrolyte is selected from sulfide-based solid electrolytes, halide-based solid electrolytes, and hydride-based solid electrolytes.

10. The anode electrode according to claim 1, wherein the solid electrolyte comprises a sulfide solid electrolyte.

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