3D porous silicon anode electrode for fast charging lithium ion battery cells

Abstract

The invention relates to a 3D porous silicon anode electrode for fast charging lithium ion battery cells. A battery cell includes A anode electrodes, where each of the A anode electrodes includes a porous anode current collector and an active material layer comprising silicon deposited onto the porous anode current collector using physical vapor deposition (PVD). The battery cell includes C cathode electrodes including a cathode current collector and a cathode active material layer disposed on the cathode current collector, and S separators, where A, C, and S are integers greater than 1.

Description

Technical Field

[0001] The present disclosure relates to battery cells of a battery pack, and more particularly to an anode electrode and a method for manufacturing an anode electrode of a battery cell of a battery pack. Background Art

[0002] The information provided in this section is for a general introduction to the background of the present disclosure. The work of the currently named inventors described in this section, and aspects of the specification that may not have been determined as prior art in other forms at the time of filing, are not expressly or implicitly admitted as prior art of the present disclosure.

[0003] 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 cells, modules, and / or packs. A power control system is used to control the charging and / or discharging of the battery pack system during charging and / or driving.

[0004] A battery 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

[0005] A battery cell includes A anode electrodes, wherein each of the A anode electrodes includes a porous anode current collector and an active material layer containing silicon deposited on the porous anode current collector using physical vapor deposition (PVD). The battery cell includes C cathode electrodes, which include a cathode current collector and a cathode active material layer disposed on the cathode current collector, and S separators, where A, C, and S are integers greater than 1.

[0006] In other features, the porous anode current collector is selected from a screen current collector, a via hole current collector, and a metal foam current collector. The porous anode current collector is made of a material selected from copper, stainless steel (SS), nickel (Ni), iron (Fe), and their alloys.

[0007] In other features, the porous anode current collector includes a screen. A first diameter of a wire of the screen is from 0.5 μm to 50 μm. A second diameter of the wire of the screen in a direction transverse to the first diameter is from 0.5 μm to 50 μm.

[0008] In other features, a thickness of the active material layer is from 0.001 μm to 30 μm. A pore diameter of the porous anode current collector is from 0.2 μm to 80 μm. A porosity of the porous anode current collector is from 30% to 99%.

[0009] Among other features, the cathode active material layer comprises a cathode active material selected from layered oxides (e.g., LiMe2O), olivine-type oxides (LiMePO4), monoclinic oxides (LiMe2(PO4)3), spinel-type oxides (e.g., LiMe2O4), tavorite represented by LiMeSO4F or LiMePO4F, where Me includes transition metals. The cathode active material layer comprises 30 wt% to 98 wt% of the cathode active material, 1 wt% to 50 wt% of a solid electrolyte, 1 wt% to 30 wt% of a conductive additive, and 1 wt% to 20 wt% of a binder.

[0010] Among other features, the solid electrolyte is selected from oxide-based solid electrolytes, metal-doped or aliovalent-substituted oxide solid electrolytes, sulfide-based solid electrolytes, nitride-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and borate-based solid electrolytes. The S separators are selected from polyolefin-based separators, cellulose separators, ceramic-coated separators, and high-temperature stable separators.

[0011] The battery pack cell includes A anode electrodes. Each of the A anode electrodes includes a wire mesh, and the active material layer comprises silicon sputtered onto the wire mesh. The battery pack cell includes C cathode electrodes, which include a cathode current collector and a cathode active material layer disposed on the cathode current collector, and S separators, where A, C, and S are integers greater than 1.

[0012] Among other features, the wire mesh is made of a material selected from copper, stainless steel (SS), nickel (Ni), iron (Fe), and their alloys. The first diameter of the wire of the wire mesh is 0.5 μm to 50 μm. The second diameter of the wire of the wire mesh in a direction transverse to the first diameter is 0.5 μm to 50 μm.

[0013] Among other features, the thickness of the active material layer is 0.001 μm to 30 μm.

[0014] The pore size of the wire mesh is 0.2 μm to 80 μm. The porosity of the wire mesh is 30% to 99%.

[0015] Among other features, the cathode active material layer comprises 30 wt% to 98 wt% of a cathode active material, 1 wt% to 50 wt% of a solid electrolyte, 1 wt% to 30 wt% of a conductive additive, and 1 wt% to 20 wt% of a binder. The cathode active material layer contains a cathode active material selected from layered oxides (e.g., LiMe2O), olivine-type oxides (LiMePO4), monoclinic oxides (LiMe2(PO4)3), spinel-type oxides (e.g., LiMe2O4), lithiophilite represented by LiMeSO4F or LiMePO4F, where Me includes transition metals.

[0016] Among other features, the solid electrolyte is selected from oxide-based solid electrolytes, metal-doped or aliovalent-substituted oxide solid electrolytes, sulfide-based solid electrolytes, nitride-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and borate-based solid electrolytes. The S separators are selected from polyolefin-based separators, cellulose separators, ceramic-coated separators, and high-temperature stable separators.

[0017] The present invention discloses the following solutions:

[0018] Solution 1. A battery pack battery, comprising:

[0019] A anode electrodes, where each of the A anode electrodes comprises:

[0020] A porous anode current collector; and

[0021] An active material layer containing silicon deposited onto the porous anode current collector using physical vapor deposition (PVD);

[0022] C cathode electrodes, comprising a cathode current collector and a cathode active material layer disposed on the cathode current collector; and

[0023] S separators, where A, C, and S are integers greater than 1.

[0024] Solution 2. The battery pack battery according to Solution 1, where the porous anode current collector is selected from screen current collectors, via-hole current collectors, and metal foam current collectors.

[0025] Solution 3. The battery pack battery according to Solution 1, where the porous anode current collector is made of a material selected from copper, stainless steel (SS), nickel (Ni), iron (Fe), and their alloys.

[0026] Solution 4. The battery pack battery according to Solution 1, where:

[0027] The porous anode current collector includes a screen; and

[0028] The first diameter of the wire of the wire mesh is from 0.5 μm to 50 μm, and

[0029] the second diameter of the wire of the wire mesh in a direction transverse to the first diameter is from 0.5 μm to 50 μm.

[0030] Solution 5. The battery pack battery according to Solution 1, wherein the thickness of the active material layer is from 0.001 μm to 30 μm.

[0031] Solution 6. The battery pack battery according to Solution 1, wherein the pore diameter of the porous anode current collector is from 0.2 μm to 80 μm.

[0032] Solution 7. The battery pack battery according to Solution 1, wherein the porosity of the porous anode current collector is from 30% to 99%.

[0033] Solution 8. The battery pack battery according to Solution 1, wherein the cathode active material layer contains a cathode active material selected from layered oxides (e.g., LiMe2O), olivine-type oxides (LiMePO4), monoclinic oxides (LiMe2(PO4)3), spinel-type oxides (e.g., LiMe2O4), tavorite represented by LiMeSO4F or LiMePO4F, wherein Me includes transition metals.

[0034] Solution 9. The battery pack battery according to Solution 1, wherein the cathode active material layer contains 30% to 98% by weight of a cathode active material, 1% to 50% by weight of a solid electrolyte, 1% to 30% by weight of a conductive additive, and 1% to 20% by weight of a binder.

[0035] Solution 10. The battery pack battery according to Solution 9, wherein the solid electrolyte is selected from oxide-based solid electrolytes, metal-doped or aliovalent-substituted oxide solid electrolytes, sulfide-based solid electrolytes, nitride-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and borate-based solid electrolytes.

[0036] Solution 11. The battery pack battery according to Solution 1, wherein the S separators are selected from polyolefin-based separators, cellulose separators, ceramic-coated separators, and high-temperature stable separators.

[0037] Solution 12. A battery pack battery, comprising:

[0038] A anode electrodes, wherein each of the A anode electrodes includes:

[0039] a wire mesh; and

[0040] An active material layer, the active material layer comprising silicon sputtered onto the wire mesh;

[0041] C cathode electrodes, comprising a cathode current collector and a cathode active material layer disposed on the cathode current collector; and

[0042] S separators, where A, C, and S are integers greater than 1.

[0043] Aspect 13. The battery pack cell according to aspect 12, wherein the wire mesh is made of a material selected from copper, stainless steel (SS), nickel (Ni), iron (Fe), and alloys thereof.

[0044] Aspect 14. The battery pack cell according to aspect 12, wherein:

[0045] A first diameter of the wire of the wire mesh is from 0.5 μm to 50 μm, and

[0046] A second diameter of the wire of the wire mesh in a direction transverse to the first diameter is from 0.5 μm to 50 μm.

[0047] Aspect 15. The battery pack cell according to aspect 12, wherein the thickness of the active material layer is from 0.001 μm to 30 μm.

[0048] Aspect 16. The battery pack cell according to aspect 12, wherein the pore size of the wire mesh is from 0.2 μm to 80 μm.

[0049] Aspect 17. The battery pack cell according to aspect 12, wherein the porosity of the wire mesh is from 30% to 99%.

[0050] Aspect 18. The battery pack cell according to aspect 12, wherein:

[0051] The cathode active material layer comprises 30 wt% to 98 wt% of a cathode active material, 1 wt% to 50 wt% of a solid electrolyte, 1 wt% to 30 wt% of a conductive additive, and 1 wt% to 20 wt% of a binder; and

[0052] The cathode active material layer comprises a cathode active material selected from layered oxides (e.g., LiMe2O), olivine-type oxides (LiMePO4), monoclinic oxides (LiMe2(PO4)3), spinel-type oxides (e.g., LiMe2O4), lithiophilite represented by LiMeSO4F or LiMePO4F, where Me includes transition metals.

[0053] Embodiment 19. The battery cell of Embodiment 18, wherein the solid electrolyte is selected from oxide-based solid electrolytes, metal-doped or aliovalent-substituted oxide solid electrolytes, sulfide-based solid electrolytes, nitride-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and borate-based solid electrolytes.

[0054] Embodiment 20. The battery cell of Embodiment 12, wherein the S separators are selected from polyolefin-based separators, cellulose separators, ceramic-coated separators, and high-temperature stable separators.

[0055] Further applicable fields of the present disclosure will be apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples are only intended to illustrate and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present disclosure will be more fully understood from the detailed description and the accompanying drawings, wherein:

[0057] Figure 1 is a side cross-sectional view of an example of a battery cell including A anode electrodes, C cathode electrodes, and S separators according to the present disclosure;

[0058] Figure 2 is a side view of an example of an anode electrode, a cathode electrode, and a separator;

[0059] Figure 3A is a scanning electron microscope image of an example of a planar silicon anode on a stainless steel current collector;

[0060] Figure 3B is a graph showing Figure 2 and 3A the charging voltage of the battery cell as a function of the percentage of state of charge (SOC%) at different charging rates;

[0061] Figure 4A is an enlarged plan view of an example of an anode electrode including a porous current collector coated with silicon using physical vapor deposition (PVD) according to the present disclosure;

[0062] Figure 4B is a side cross-sectional view of an example of an anode electrode including a porous current collector coated with a silicon layer using physical vapor deposition (PVD) according to the present disclosure;

[0063] Figure 5 is a functional block diagram of an example of a magnetron for sputtering a silicon layer onto a porous current collector according to the present disclosure;

[0064] Figure 6is a side cross-sectional view of an example of a battery cell of a battery pack including an anode electrode, a cathode electrode, a separator, and a liquid electrolyte according to the present disclosure;

[0065] Figure 7 is a side cross-sectional view of an example of a solid-state battery cell of a solid-state battery pack including an anode electrode, a cathode electrode, a separator, and a solid electrolyte according to the present disclosure;

[0066] Figure 8 and 9 is a scanning electron microscope image of an example of a porous anode current collector having a silicon layer according to the present disclosure;

[0067] Figure 10 is a graph showing an example of an X-ray diffraction (XRD) pattern of a porous anode current collector and a porous silicon anode electrode according to the present disclosure;

[0068] Figure 11 is a graph showing an example of a Raman spectrum of a porous silicon anode electrode according to the present disclosure;

[0069] Figure 12A is a graph showing an example of voltage as a function of SOC% of a planar silicon anode electrode and a porous silicon anode electrode according to the present disclosure; and

[0070] Figure 12B is a graph showing an example of SOC% as a function of time of a planar silicon anode electrode and a porous silicon anode electrode according to the present disclosure.

[0071] In the drawings, reference numerals may be reused to designate similar and / or identical elements. Detailed Description

[0072] Although the battery cell of the battery pack according to the present disclosure is shown in the context of an electric vehicle, the battery cell of the battery pack can be used for stationary applications and / or other applications.

[0073] An anode electrode using silicon as an anode active material is a promising alternative to an anode electrode using graphite. Silicon is environmentally friendly and has a reasonable electrochemical potential (-0.3V vs. Li / Li + ) and a high theoretical capacity (4200 mAh / g for Li44Si). Although the silicon anode electrode provides multiple lithiation and delithiation pathways during battery pack cycling, silicon is not the best anode active material for fast charging. The planar silicon anode electrode suffers from low intrinsic conductivity (<10 -5 Siem / cm) at room temperature, which deteriorates the battery pack rate performance and hinders fast charging use.

[0074] The present disclosure relates to a porous silicon anode electrode that includes a porous anode current collector with a silicon layer deposited by PVD. In some examples, a uniform silicon anode active material is deposited by PVD on a 3D copper mesh current collector to enable fast charging. The 3D copper mesh of the anode electrode provides an effective electron conduction network to create a fast electron transport path. The porous structure of the 3D copper mesh provides sufficient space for the electrolyte to facilitate lithium ion transport while accommodating the change in silicon volume during cycling. The deposited amorphous Si layer is binder-free and can reduce the internal resistance of the battery pack cell. As a result, the porous silicon anode electrode is capable of enhancing the fast charging ability.

[0075] 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 predetermined order in a battery pack cell stack 12, where C, S, and A are integers greater than zero. The battery pack cell stack 12 is disposed in a housing 50. The C cathode electrodes 20-1, 20-2, ..., and 20-C include cathode active material layers 24 disposed on one or both sides of a cathode current collector 26. The A anode electrodes 40-1, 40-2, ..., and 40-A include anode active material layers 42 disposed on an anode current collector 46. In some examples, the A anode electrodes 40 and the C cathode electrodes 20 exchange lithium ions during charging / discharging.

[0076] In some examples, the anode active material layer 42 includes a silicon layer deposited by PVD on the anode current collector 46. The anode current collector 46 includes a porous current collector, such as a screen current collector, a via hole current collector (e.g., a perforated foil), a metal foam current collector, and / or other high porosity current collector materials. In some examples, the cathode active material layer 24 includes a coating that includes one or more active materials, one or more conductive additives, and / or one or more binder materials applied (cast or laminated) on the current collector.

[0077] In some examples, the cathode current collector 26 includes a metal foil, a metal mesh, a perforated metal, a three-dimensional (3D) metal foam, and / or an expanded metal. In some examples, the cathode 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 connected to the current collectors of the cathode electrode and the anode electrode, respectively, and can be disposed 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. In some examples, the battery pack cell 10 uses a liquid electrolyte 52. In other examples, the separator 32 and the cathode active material layer 24 include a solid-solid electrolyte, a gel electrolyte, and / or a liquid electrolyte.

[0078] Now referring to Figures 2 to 3B, the anode electrode 60 includes a planar silicon anode active material 62 deposited on a planar current collector 66 (e.g., stainless steel). In Figure 3A , a scanning electron microscope image of the anode electrode 60 is shown. In Figure 3B , the charging voltage of the anode electrode 60 is shown as a function of the state of charge percentage (SOC%) for different charging rates (C / 3, 1C, 2C, 3C, and 4C). The separator 32 includes a polymer separator and a liquid electrolyte 52 is used. It can be understood that the anode electrode 60 is dense and does not allow sufficient space to buffer the expansion of silicon. Silicon is a semiconductor and has a low electrical conductivity (<10 -5 Siem / cm) at room temperature. It can be understood that ineffective electron transport paths result in poor fast charging capabilities.

[0079] Now refer to Figure 4A and 4B , the anode electrode 110 according to the present disclosure is shown to include a porous anode current collector 112 and an anode active material layer 114 containing silicon. Silicon is PVD deposited on the porous anode current collector 112 using a magnetron sputtering method. In Figure 4B , the porous anode current collector 112 includes first and second sets of wire elements 115 and 117 that cross and interlace with each other at a predetermined angle (e.g., laterally). The wire elements of the first and second sets of wire elements have a first diameter d Cu1 and a second diameter d Cu1 transverse to the first diameter d Cu2 . The anode active material layer 114 is deposited on the porous anode current collector 112 with a thickness d Si . The spacing between adjacent wire elements of the porous anode current collector 112 is equal to d p .

[0080] In some instances, d Cu1 is from 0.5 μm to 50 μm. In other instances, d Cu1 is from 1 μm to 30 μm. In some instances, d Cu2 is from 0.5 μm to 50 μm. In other instances, d Cu2 is from 1 μm to 30 μm. In some instances, the porous anode current collector 112 is made of a material selected from copper, stainless steel (SS), nickel (Ni), iron (Fe), alloys of these materials, and / or other conductive materials.

[0081] In some instances, the thickness d Si of the anode active material layer 114 is from 0.001 μm to 30 μm. In some instances, the thickness d Siis from 0.05 μm to 20 μm. In some examples, the areal capacity loading of the anode active material layer 114 is 0.5 mAh / cm 2 to 20 mAh / cm 2 . In other examples, the areal capacity loading of the anode active material layer 114 is 3 mAh / cm 2 to 10 mAh / cm 2 .

[0082] In some examples, the spacing (or pore size) d between the wires P is from 0.2 μm to 80 μm. In other examples, the spacing (or pore size) d P is from 5 μm to 50 μm. In some examples, the porosity is from 30% to 99%. In other examples, the porosity is from 70% to 99%. In other examples, the mesh current collector can be replaced by through holes, foams, and other high-porosity current collector materials.

[0083] In some examples, a screen current collector is used and provides an effective electron conduction network and a uniform electric field distribution to create a path for fast electron transport in the silicon-based anode electrode. The anode electrode provides sufficient porous space for the liquid electrolyte to facilitate lithium-ion transport and shorten the ion diffusion path. Porous space is also provided to accommodate the volume change of silicon during lithiation and delithiation. The deposited silicon active material provides a uniform and amorphous Si layer to achieve good battery cycling performance. The active material layer does not contain an insulating polymer binder that can increase the internal resistance. As a result, the porous silicon anode electrode is more conductive, which enhances the fast charging ability of the battery pack cells.

[0084] Now referring to Figure 5 , a DC magnetron sputtering apparatus 200 deposits an anode active material layer 42 on a porous anode current collector 112. The porous anode current collector 112 is disposed on a substrate support 214 in a processing chamber 210. A magnetron cathode 216 including a magnet 220 and a target 218 is spaced apart from the substrate support 214.

[0085] During deposition, a process gas mixture such as argon (Ar) from a gas source 222 is introduced into the processing chamber 210 while supplying AC and / or DC power. In some examples, a mass flow controller 224 and a valve 226 are used to meter the process gas entering the processing chamber 210 from the gas source 222. A throttle valve 234 and / or a pump 238 control the pressure inside the processing chamber 210 and / or discharge reactants from the processing chamber 210. A DC source 244 supplies a DC voltage to the magnetron cathode 216. An AC source 246 supplies an AC voltage to the magnetron cathode 216.

[0086] During deposition, target material (e.g., silicon) is ejected from target 218 and deposited on porous anode current collector 112. Material is also sputtered from the exposed surface of porous anode current collector 112. In some examples, a silicon target (e.g., n-type; 99.995%) sputters silicon particles onto a porous anode current collector (e.g., copper mesh). In some examples, the DC source 244 supplies a DC voltage of 200V to 800V. In some examples, the cathode power from AC source 246 is 2 to 30 kW and the frequency is 20 to 200 kHz. In some examples, the deposition time is 20 to 840 minutes.

[0087] Now refer Figure 6 and Figure 7 , an example of a battery cell of a battery pack including a porous anode electrode is shown. In Figure 6 , a battery pack cell 300 based on a liquid electrolyte is shown. The battery pack cell 300 based on a liquid electrolyte includes an anode electrode 110, a separator 32 (e.g., a polymer separator), a cathode electrode 20 including a cathode active material layer 24, and a liquid electrolyte 52 (e.g., LiPF6 in carbonate).

[0088] In Figure 7 , a solid-state or semi-solid battery pack cell 350 is shown. The battery pack cell 350 includes an anode electrode 110, a separator 132 (e.g., a solid electrolyte layer), and a cathode electrode 20. The cathode electrode 20 includes a cathode active material layer 24 and a solid electrolyte 136. In some examples, the battery pack cell 350 is a solid-state battery pack cell. In other examples, a liquid electrolyte or a gel electrolyte can be used to enhance the power capacity.

[0089] In some examples, the cathode electrode contains 30 wt% to 98 wt% of cathode active material, 0 wt% to 50 wt% of solid electrolyte, 0 wt% to 30 wt% of conductive additive, and 0 wt% to 20 wt% of binder.

[0090] In some examples, the cathode active material is selected from layered oxides (e.g., LiMe2O), olivine-type oxides (LiMePO4), monoclinic oxides (LiMe2(PO4)3), spinel-type oxides (e.g., LiMe2O4), lithiophosphate olivine represented by LiMeSO4F or LiMePO4F, where Me includes transition metals.

[0091] In some examples, the conductive additive is selected from carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronic conductive additives.

[0092] In some instances, the binder is selected from poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(tetrafluoroethylene) (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), styrene-ethylene-butene-styrene copolymer (SEBS), and combinations thereof.

[0093] In some instances, the separator for a battery cell of a battery pack based on a liquid electrolyte includes a polyolefin-based separator, a cellulose separator, a ceramic-coated separator, and a high-temperature stable separator. In some instances, the liquid electrolyte wets 5% to 100% (e.g., 90%) of the porosity of the separator.

[0094] Examples of polyolefin-based separators include polyacetylene, polypropylene (PP), polyethylene (PE), bilayer type (PP / PE), and trilayer type (PP / PC / PP). Examples of cellulose separators include polyvinylidene fluoride (PVDF) membranes and porous polyimide membranes. Examples of ceramic-coated separators include SiOx-coated PE. Examples of high-temperature stable separators include nonwoven materials based on polyimide (PI) nanofibers, nanosized Al2O3, and poly(4-styrenesulfonic acid lithium)-coated polyethylene membranes, Si-coated polyethylene (PE) separators, copolyimide-coated polyethylene separators, polyetherimide (PEI) (bisphenol-acetone dianhydride (BPADA) and p-phenylenediamine) separators, expanded polytetrafluoroethylene-reinforced polyvinylidene fluoride-hexafluoropropylene separators, sandwich-structured PVdF / PMIA / PVdF nanofiber separators, and the like.

[0095] In some instances, the solid electrolyte is selected from oxide-based solid electrolytes, metal-doped or aliovalent-substituted oxide solid electrolytes, sulfide-based solid electrolytes, nitride-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and borate-based solid electrolytes.

[0096] Examples of oxide-based solid electrolytes include garnet type (e.g., Li7La3Zr2O 12 ), perovskite type (e.g., Li 3x La 2 / 3-x TiO3), NASICON type (e.g., Li 1.4 Al 0.4 Ti 1.6 (PO4)3 and Li 1+x Al x Ge 2-x(PO4)3) and LISICON type (e.g., Li 2+2x Zn 1-x GeO4).

[0097] Examples of metal-doped or aliovalent-substituted oxide solid electrolytes include Al (or Nb)-doped Li7La3Zr2O 12 , Sb-doped Li7La3Zr2O 12 , Ga-substituted Li7La3Zr2O 12 , Cr and V-substituted LiSn2P3O 12 and Al-substituted perovskite Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 .

[0098] Examples of sulfide-based solid electrolytes include the Li2S-P2S5 system, the Li2S-P2S5-MO X system, the Li2S-P2S5–MS x system, LGPS (Li 10 GeP2S 12 ), thio-LISICON (Li 3.25 Ge 0.25 P 0.75 S4), Li 3.4 Si 0.4 P 0.6 S4, Li 10 GeP2S 11.7 O 0.3 , lithium argyrodite Li6PS5X (X = Cl, Br or I), Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (25 mS / cm), Li 9.6 P3S 12 , Li7P3S 11 , Li9P3S9O3, Li 10.35 Ge 1.35 P 1.65 S 12 , Li 10.35 Si 1.35 P 1.65 S 12 , Li 9.81 Sn 0.81 P 2.19 S 12 , Li10 (Si 0.5 Ge 0.5 )P2S 12 、Li 10 (Ge 0.5 Sn 0.5 )P2S 12 、Li 10 (Si 0.5 Sn 0.5 )P2S 12 、Li 3.833 Sn 0.833 As 0.166 S4, LiI - Li4SnS4, and Li4SnS4.

[0099] Examples of nitride - based solid electrolytes include Li3N, Li7PN4, and LiSi2N3. Examples of hydride - based solid electrolytes include LiBH4, LiBH4 - LiX (X = Cl, Br, or I), LiNH2, Li2NH, LiBH4 - LiNH2, and Li3AlH6. Examples of halide - based solid electrolytes include LiI, Li3InCl6, Li2CdCl4, Li2MgCl4, Li2CdI4, Li2ZnI4, and Li3OCl. Examples of borate - based solid electrolytes include Li2B4O7 and Li2O - B2O3 - P2O5.

[0100] Now refer to Figure 8 and Figure 9 , scanning electron microscope images show the porous current collector before ( Figure 8 ) and after ( Figure 9 ) sputtering the silicon layer on the current collector. It can be seen that the sputtering of the silicon layer does not affect the 3D porous structure of the current collector.

[0101] Now refer to Figure 10 and 11 , showing the X - ray diffraction (XRD) and Raman analysis of the porous 3D silicon anode electrode. In Figure 10 , the 3D porous silicon anode electrode is amorphous and has no XRD diffraction peaks corresponding to silicon. In Figure 11 , the main peak at 475 cm -1 can be attributed to the transverse optical (TO) mode of amorphous silicon (a - Si).

[0102] Now refer to Figure 12A and 12B , showing the fast - charging performance of the porous silicon anode electrode. In Figure 12A , the voltage as a function of the state of charge (SOC%) at 25 °C is shown. In Figure 12BTherein, the SOC% of the porous silicon anode electrode at 420 and the planar silicon anode electrode at 400 are shown as a function of time. It can be seen that the porous anode electrode provides improved fast charging ability.

[0103] The foregoing description is merely exemplary and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be implemented in a variety of forms. Thus, 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 the embodiments are described above as having certain features, any one or more of the features described with respect to any one embodiment of the disclosure may be implemented in and / or combined with the features of any other embodiment, even if not explicitly described in that combination. In other words, the described embodiments are not mutually exclusive, and permutations of one or more of the embodiments are still within the scope of the disclosure.

[0104] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected", "joined", "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 element and the second element, or an indirect relationship in which one or more intervening elements exist (spatially or functionally) between the first element and the second element. 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".

[0105] In the drawings, the direction of an arrow as shown by the arrow generally shows the information flow (such as data or instructions) of interest in the illustration. For example, when element A and element B exchange various information but the information sent from element A to element B is relevant to the illustration, the arrow may point from element A to element B. Such a unidirectional arrow does not mean that no other information is sent from element B to element A. Further, for the information transmitted from element A to element B, element B may send a request for that information or receive an acknowledgement from element A.

Claims

1. A battery cell for a battery pack, comprising: A anode electrodes, wherein each of the A anode electrodes comprises: A porous anode current collector; and An active material layer comprising silicon deposited by physical vapor deposition (PVD) onto the porous anode current collector; C cathode electrodes, comprising a cathode current collector and a cathode active material layer disposed on the cathode current collector; and S separators, wherein A, C, and S are integers greater than 1.

2. The battery cell for a battery pack according to claim 1, wherein the porous anode current collector is selected from a screen current collector, a via hole current collector, and a metal foam current collector.

3. The battery cell for a battery pack according to claim 1, wherein the porous anode current collector is made of a material selected from copper, stainless steel (SS), nickel (Ni), iron (Fe), and alloys thereof.

4. The battery cell for a battery pack according to claim 1, wherein: The porous anode current collector comprises a screen; and A first diameter of the wire of the screen is from 0.5 μm to 50 μm, and A second diameter of the wire of the screen in a direction transverse to the first diameter is from 0.5 μm to 50 μm.

5. The battery cell for a battery pack according to claim 1, wherein the thickness of the active material layer is from 0.001 μm to 30 μm.

6. The battery cell for a battery pack according to claim 1, wherein the pore size of the porous anode current collector is from 0.2 μm to 80 μm.

7. The battery cell for a battery pack according to claim 1, wherein the porosity of the porous anode current collector is from 30% to 99%.

8. The battery cell for a battery pack according to claim 1, wherein the cathode active material layer comprises a cathode active material selected from layered oxides (e.g., LiMe2O), olivine-type oxides (LiMePO4), monoclinic oxides (LiMe2(PO4)3), spinel-type oxides (e.g., LiMe2O4), tavorite represented by LiMeSO4F or LiMePO4F, wherein Me comprises a transition metal.

9. The battery cell for a battery pack according to claim 9, wherein the cathode active material layer comprises 30 wt% to 98 wt% of a cathode active material, 1 wt% to 50 wt% of a solid electrolyte, 1 wt% to 30 wt% of a conductive additive, and 1 wt% to 20 wt% of a binder.

10. The battery cell for a battery pack according to claim 9, wherein the solid electrolyte is selected from oxide-based solid electrolytes, metal-doped or aliovalent-substituted oxide solid electrolytes, sulfide-based solid electrolytes, nitride-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and borate-based solid electrolytes.

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