Battery cell comprising functionalized separator

Abstract

A battery cell includes a functionalized separator. A battery cell includes C cathode electrodes, A anode electrodes, and S separators, where C, A, and S are integers greater than zero. Each of the S separators includes a separator layer, a first active solid coating layer disposed on the separator layer, and a protective layer.

Description

Technical Field

[0001] This disclosure relates to a battery pack and a battery pack battery. Background Technology

[0002] The information provided in this section is for the purpose of giving a general overview of the background of this disclosure. The work of the currently named inventors (to the extent described in this section) and aspects of the description which at the time of filing may not otherwise constitute prior art are neither explicitly nor implicitly considered to be prior art relative to this disclosure.

[0003] This disclosure relates to battery packs, and more specifically to battery packs including functionalized separators.

[0004] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid vehicles, and / or fuel cell vehicles, include one or more motors and battery pack systems, the battery pack system including one or more battery cells, battery 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] The battery pack includes a cathode electrode, an anode electrode, and a separator. The cathode electrode includes a layer of cathode active material disposed on a cathode current collector. The anode electrode includes a layer of anode active material disposed on an anode current collector. Summary of the Invention

[0006] The battery pack includes C cathode electrodes, A anode electrodes, and S separators, where C, A, and S are integers greater than zero. Each of the S separators includes a separator layer, a first active solid coating disposed on the separator layer, and a protective layer.

[0007] Among other features, each of the S spacers also includes a second active coating. The spacer layer is arranged adjacent to one of the C cathode electrodes. A first active solid coating is arranged adjacent to the spacer layer. A protective layer is disposed between the first active solid coating and one of the A anode electrodes.

[0008] Among other features, the second active coating is arranged adjacent to one of the C cathode electrodes. An insulating layer is arranged adjacent to the second active coating. The first active solid coating is arranged adjacent to the insulating layer. A protective layer is arranged between the first active solid coating and one of the A anode electrodes.

[0009] Among other features, the first active solid coating comprises active solid particles that react with lithium. The active solid particles are selected from Li... 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 0.33La 0.56 TiO3(LLTO), Si, Sn, Li2S-P2S5-GeS2 system, Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 The particle size of the active solid particles ranges from 10 nm to 1000 nm.

[0010] Among other features, the first active solid coating has a thickness of 1 μm to 10 μm. The protective layer comprises a polymer selected from polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO). The protective layer has a thickness of 1 μm to 5 μm.

[0011] Among other features, the spacer layer is selected from polyolefin-based spacer layers, cellulose spacer layers, polyvinylidene fluoride (PVDF) layers, and porous polyimide layers. The spacer layer has a thickness of 6 μm to 25 μm.

[0012] Among other features, A anode electrode comprises an anode active material selected from lithium metal and lithium metal composites. C cathode electrode comprises 30 to 98% by weight of cathode active material. The cathode active material is selected from layered oxides, olivine oxides, monoclinic oxides, spinel oxides, sulfides / sulfur (S), and lithium sulfide (Li₂S), wherein M is a transition metal.

[0013] Among other features, the C cathode electrodes further comprise 1 to 30% by weight of at least one conductive additive selected from carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronically conductive additives; and 1 to 20% by weight of a binder 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 rubber (NBR), and styrene-ethylene-butene-styrene copolymer (SEBS).

[0014] A battery pack includes C cathode electrodes, A anode electrodes (containing an anode active material selected from lithium metal and lithium metal composites), and S separators, wherein C, A, and S are integers greater than zero. Each of the S separators includes a separator layer, and materials disposed on the separator layer and containing materials selected from lithium metal. 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 0.33 La 0.56TiO3(LLTO), Si, Sn, Li2S-P2S5-GeS2 system, Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 The active solid particles are a first active solid coating and a protective layer disposed on the first active solid coating.

[0015] Among other features, each of the S spacers also includes a second active solid coating disposed between the spacer layer and one of the C cathode electrodes. The particle size of the active solid particles is from 10 nm to 1000 nm. The thickness of the first active solid coating is from 1 μm to 10 μm. The protective layer comprises a polymer selected from polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO). The protective layer has a thickness from 1 μm to 5 μm.

[0016] Among other features, the spacer layer is selected from polyolefin-based spacer layers, cellulose spacer layers, polyvinylidene fluoride (PVDF) layers, and porous polyimide layers. The spacer layer has a thickness of 6 μm to 25 μm.

[0017] Among other features, the C cathode electrodes contain 30 to 98% by weight of cathode active material. The cathode active material is selected from layered oxides, olivine oxides, monoclinic oxides, spinel oxides, sulfides / sulfur (S), and lithium sulfide (Li₂S), where M is a transition metal.

[0018] The present invention discloses the following implementation scheme:

[0019] 1. A battery pack, comprising:

[0020] C cathode electrodes;

[0021] A anode electrode; and

[0022] There are S isolation components, where C, A, and S are integers greater than zero.

[0023] Each of the S isolation components includes:

[0024] Isolation layer;

[0025] A first active solid coating is disposed on the insulating layer; and

[0026] Protective layer.

[0027] 2. The battery pack according to embodiment 1, wherein each of the S separators further comprises a second active coating.

[0028] 3. The battery pack according to implementation scheme 1, wherein:

[0029] The insulating layer is arranged adjacent to one of the C cathode electrodes;

[0030] The first active solid coating is arranged adjacent to the separator layer; and

[0031] The protective layer is disposed between the first active solid coating and one of the A anode electrodes.

[0032] 4. The battery pack according to embodiment 2, wherein:

[0033] The second active coating is arranged adjacent to one of the C cathode electrodes;

[0034] The insulating layer is arranged adjacent to the second active coating;

[0035] The first active solid coating is arranged adjacent to the insulating layer; and

[0036] A protective layer is disposed between the first active solid coating and one of the A anode electrodes.

[0037] 5. The battery pack according to embodiment 1, wherein the first active solid coating comprises active solid particles that react with lithium.

[0038] 6. The battery pack according to embodiment 5, wherein the active solid particles are selected from Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 0.33 La 0.56 TiO3(LLTO), Si, Sn, Li2S-P2S5-GeS2 system, Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 .

[0039] 7. The battery pack according to embodiment 6, wherein the particle size of the active solid particles is 10 to 1000 nanometers.

[0040] 8. The battery pack according to embodiment 5, wherein the thickness of the first active solid coating is 1 μm to 10 μm.

[0041] 9. The battery pack according to embodiment 1, wherein the protective layer comprises a polymer selected from polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO).

[0042] 10. The battery pack according to embodiment 9, wherein the protective layer has a thickness of 1 μm to 5 μm.

[0043] 11. The battery pack according to embodiment 1, wherein the separator layer is selected from polyolefin-based separator layers, cellulose separator layers, polyvinylidene fluoride (PVDF) layers, and porous polyimide layers.

[0044] 12. The battery pack according to embodiment 11, wherein the separator layer has a thickness of 6 μm to 25 μm.

[0045] 13. The battery pack according to embodiment 1, wherein:

[0046] Anode electrode A comprises an anode active material selected from lithium metal and lithium metal composites, and cathode electrode C comprises 30 to 98% by weight of cathode active material.

[0047] The cathode active material is selected from layered oxides, olivine oxides, monoclinic oxides, spinel oxides, sulfides / sulfur (S) and lithium sulfide (Li2S), where M is a transition metal.

[0048] 14. The battery pack according to embodiment 1, wherein the C cathode electrodes further comprise at least one of the following:

[0049] 1 to 30% by weight of a conductive additive, wherein the conductive additive is selected from carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronically conductive additives; and

[0050] 1 to 20% by weight of an adhesive, wherein the adhesive 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 rubber (NBR), and styrene-ethylene-butene-styrene copolymer (SEBS).

[0051] 15. A battery pack, comprising:

[0052] C cathode electrodes;

[0053] A cathode electrode comprising an anode active material selected from lithium metal and lithium metal composites; and

[0054] There are S isolation components, where C, A, and S are integers greater than zero.

[0055] Each of the S isolation components includes:

[0056] Isolation layer;

[0057] A first active solid coating, disposed on the insulating layer and comprising a material selected from Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 0.33 La 0.56 TiO3(LLTO), Si, Sn, Li2S-P2S5-GeS2 system, Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 Active solid particles; and

[0058] A protective layer is disposed on the first active solid coating.

[0059] 16. The battery pack according to embodiment 15, wherein each of the S separators further comprises a second active solid coating disposed between the separator layer and one of the C cathode electrodes.

[0060] 17. The battery pack according to embodiment 15, wherein:

[0061] The active solid particles have a particle size of 10 nm to 1000 nm; and

[0062] The thickness of the first active solid coating is 1 μm to 10 μm.

[0063] 18. The battery pack according to embodiment 15, wherein:

[0064] The protective layer comprises a polymer selected from polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO); and

[0065] The protective layer has a thickness of 1 μm to 5 μm.

[0066] 19. The battery pack according to embodiment 15, wherein:

[0067] The insulating layer is selected from polyolefin-based insulating layers, cellulose insulating layers, polyvinylidene fluoride (PVDF) layers, and porous polyimide layers; and

[0068] The isolation layer has a thickness of 6μm to 25μm.

[0069] 20. The battery pack according to embodiment 15, wherein:

[0070] The C cathode electrodes comprise 30 to 98% by weight of cathode active material, and

[0071] The cathode active material is selected from layered oxides, olivine oxides, monoclinic oxides, spinel oxides, sulfides / sulfur (S) and lithium sulfide (Li2S), where M is a transition metal.

[0072] Further applications of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific implementations are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0073] This disclosure will be more fully understood from the detailed embodiments and accompanying drawings, in which:

[0074] Figure 1 This is a cross-section of an example of a battery pack including an anode electrode, a cathode electrode, and a functionalized separator according to the present disclosure;

[0075] Figure 2 This is an enlarged side cross-section of an example of a battery pack including a functionalized separator according to the present disclosure;

[0076] Figure 3 Examples of active solid coatings for functionalized separators that react with lithium dendrites according to this disclosure are shown;

[0077] Figure 4 This is a side cross-section of an example of a battery pack according to the present disclosure, the battery pack including an anode electrode and a functionalized separator having first and second active solid coatings;

[0078] Figure 5 It is based on the energy dispersive spectral elemental distribution of the active solid coating of the functionalized isolation component according to this disclosure;

[0079] Figure 6 This is a diagram showing the X-ray diffraction pattern of the active solid coating of the functionalized separator according to this disclosure; and

[0080] Figure 7 It is a graph showing the electrochemical performance (voltage as a function of time), for example, the electrochemical performance (voltage as a function of time) of a battery pack including conventional separators and a battery pack including functionalized separators according to this disclosure.

[0081] In the accompanying drawings, reference numerals may be used repeatedly to identify similar and / or identical elements. Detailed Implementation

[0082] Although the battery packs according to this disclosure are shown in the context of an electric vehicle, the battery packs can be used in stationary applications and / or other applications.

[0083] Lithium is the most promising anode active material for next-generation rechargeable battery packs. Lithium possesses a high theoretical specific capacity (3860 mAh / g) and a low density (0.534 g / cm³). 3 The battery pack features a low electrochemical potential (-3.040 V vs. SHE). However, uneven lithium dissolution / coating during operation is a significant problem for rechargeable Li-metal battery packs. When the battery pack operates at high charging currents, lithium dendrites form at the lithium anode electrode and grow in the direction of the separator and cathode electrode. In some cases, lithium dendrites can penetrate the separator and contact the cathode electrode, causing a short circuit in the battery pack.

[0084] The functionalized separator according to this disclosure includes a primary separator layer, an active solid coating disposed on one side of the separator layer, and a protective layer disposed on the active solid coating. The protective layer increases the mechanical strength of the separator to reduce Li dendrite infiltration into the separator layer and / or the cathode electrode.

[0085] If lithium dendrites can penetrate the protective layer, the active solid coating reacts with the lithium dendrites to eliminate and / or destroy them. As a result, the functionalized separator makes the lithium metal battery pack less prone to short circuits at high current densities and improves the cycle performance of the lithium metal battery pack.

[0086] Now for reference Figure 1 The battery pack 10 includes C cathode electrodes 20, A anode electrodes 40, and S functionalized separators 32 arranged in a predetermined order within a battery pack stack 12, where C, S, and A are integers greater than zero. The battery pack stack 12 is disposed within a housing 50 including a liquid electrolyte 52. The C cathode electrodes 20-1, 20-2, ..., 20-C include a cathode active material layer 24 on one or both sides of a cathode current collector 26. The A anode electrodes 40-1, 40-2, ..., 40-A include an anode active material layer 42 disposed on one or both sides of an anode current collector 46.

[0087] During charging / discharging, A anode electrodes 40 and C cathode electrodes 20 exchange lithium ions. In some instances, the cathode active material layer 24 includes a coating comprising one or more cathode active materials, one or more conductive additives, and / or one or more binder materials applied to the current collector.

[0088] In some instances, the cathode current collector 26 and / or the anode current collector 46 comprises metal foil, metal mesh, perforated metal, 3D metal foam, and / or porous metal mesh. In some instances, the current collector is made of one or more materials selected from copper, stainless steel, brass, bronze, zinc, aluminum, and / or alloys thereof. External tabs 28 and 48 are connected to the current collectors of the cathode and anode electrodes, respectively, and may be arranged on the same or different sides of the battery stack 12. External tabs 28 and 48 are connected to the ends of the battery cells in the battery pack.

[0089] Now for reference Figure 2 The battery pack 100 includes a cathode electrode 120, a functionalized separator 132, an anode electrode 140, and a liquid electrolyte 152. The cathode electrode 120 includes a cathode active material 162, an optional conductive filler 164, and an optional binder 166. The anode electrode 140 includes an anode active material layer 142 and an anode current collector 146. In some examples, the anode active material layer 142 includes a lithium metal layer. The functionalized separator 132 includes a separator layer 180, an active solid coating 184, and a protective layer 186. The active solid coating 184 includes active solid particles 182 that react with lithium dendrites 199 that pierce the protective layer 186.

[0090] Now refer to Figure 3 When lithium dendrites pierce the protective layer 186 and contact the active solid coating 184, the active solid coating 184 reacts with the lithium dendrites. Lithium reacts with the active solid particles 182 to prevent further growth of lithium dendrites and the formation of one or more other compounds (e.g., some or all of which may be insulating materials). For example, Li... 1.3 Al 0.3 Ti 1.7 (PO4)3 reacts with lithium to form Ti3P, TiAl, Li3P and Li2O.

[0091] Now for reference Figure 4 The functional separator 202 of the other battery pack 200 also includes an active solid coating 210 disposed between the functional separator 202 and the cathode electrode 120. No protective layer is disposed between the functional separator 202 and the cathode electrode 120.

[0092] Now refer to Figure 5 and 6 Details are shown regarding an example of a functionalized separator incorporating LATP as an active solid coating. Figure 5 The energy dispersive spectral elemental distribution of the active solid coating of the functionalized isolator is shown in the figure. Figure 6 The image shows the X-ray diffraction pattern of the active solid coating on the functionalized isolator. The active solid coating can be successfully introduced into the functionalized isolator and uniformly dispersed on the isolator layer.

[0093] Now for reference Figure 7 The diagram illustrates the electrochemical performance (voltage as a function of time) of a battery pack, for example, including a conventional separator at 310 and a functional separator at 320. As can be seen at 330, the battery pack including the conventional separator experiences short-circuit and unstable performance, while the battery pack with the functional separator does not experience short-circuit and unstable performance.

[0094] In some instances, the active solid coating comprises active solid particles that can react with lithium. In some instances, the solid particles are selected from Li. 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 0.33 La 0.56 TiO3(LLTO), Si, Sn, Li2S-P2S5-GeS2 system and (Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 In some instances, the active particles are insoluble in the liquid electrolyte. In some instances, the particle size of the active particles is from 10 nm to 1000 nm. In some instances, the active particles are coated onto the separator layer using spraying or casting techniques. In some instances, the active solid coating has a thickness of 1 μm to 10 μm. In some instances, the active solid coating comprises LATP with a thickness of 2 μm to 4 μm (e.g., 3 μm).

[0095] In some instances, the protective layer reduces or prevents direct contact between lithium dendrites and the active solid coating. In some instances, the protective layer comprises a polymer layer. In some instances, the polymer layer is selected from polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO). In some instances, the protective layer is applied by a casting method or molecular layer deposition (MLD) technique. In some instances, the protective layer has a thickness of 1 μm to 5 μm. In some instances, the protective layer comprises PVDF with a thickness of 0.5 μm to 2 μm (e.g., 1 μm).

[0096] In some instances, the spacer layer supports both the active solid coating and the protective layer. Examples of spacer layers include polyolefin-based spacer layers (e.g., polyacetylene-polypropylene (PP), polyethylene (PE), bilayer (PP-PE), trilayer (PP-PE-PP), cellulose spacer layers, polyvinylidene fluoride (PVDF) layers, and porous polyimide layers. In some instances, the spacer layer has a thickness of 6 μm to 25 μm.

[0097] In some examples, the cathode electrode comprises 30% to 98% by weight of cathode active material, 1% to 30% by weight of optional conductive additives, and 1% to 20% by weight of optional binder. In some examples, the cathode active material is selected from layered oxides (represented by the formula LiMO2), olivine-type oxides (represented by the formula LiMPO4), monoclinic oxides (represented by the formula Li3M2(PO4)3), spinel-type oxides (represented by the formula LiM2O4), where M is a transition metal (e.g., Co, Ni, Mn, Fe, Al, V, or combinations thereof), sulfide / sulfur (S), and / or lithium sulfide (Li2S).

[0098] In some instances, the conductive additives are selected from carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronically conductive additives.

[0099] In some instances, the adhesive 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 rubber (NBR), and styrene-ethylene-butene-styrene copolymer (SEBS).

[0100] In some instances, the anode electrode comprises an anode active material selected from lithium metal or lithium metal composites. In some instances, the lithium metal composite is represented by Li / Y containing a lithium metal phase, where Y can be Ag, Sn, C, Si, etc.

[0101] The foregoing description is illustrative in nature and is in no way intended to limit this disclosure, its application, or use. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the drawings, description, and appended claims. It should be understood that one or more steps within the method may be performed in different orders (or simultaneously) without altering the principles of this disclosure. Furthermore, although each of the embodiments described above is characterized by certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented in any of the other embodiments and / or combined with features of any of the other embodiments, even if such combinations are not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments for each other remains within the scope of this disclosure.

[0102] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including “connection,” “joint,” “coupled,” “adjacent,” “next to,” “on top,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when a relationship between the first and second elements is described in the foregoing disclosure, the relationship can be a direct relationship in which no other intermediate elements exist between the first and second elements, or an indirect relationship in which one or more intermediate elements exist between the first and second elements (spatially or functionally). As used herein, at least one of the phrases A, B, and C should be interpreted as indicating logic using non-exclusive OR (A OR B OR C) and should not be interpreted as indicating “at least one of A, at least one of B, and at least one of C.”

Claims

1. A battery pack, comprising: C cathode electrodes; A anode electrode; as well as There are S isolation components, where C, A, and S are integers greater than zero. Each of the S isolation components includes: Isolation layer; A first active solid coating is disposed on the insulating layer; and Protective layer.

2. The battery pack according to claim 1, wherein each of the S separators further comprises a second active coating.

3. The battery pack according to claim 1, wherein: The insulating layer is arranged adjacent to one of the C cathode electrodes; The first active solid coating layer is arranged adjacent to the isolation layer; as well as The protective layer is disposed between the first active solid coating and one of the A anode electrodes.

4. The battery pack according to claim 2, wherein: The second active coating is arranged adjacent to one of the C cathode electrodes; The insulating layer is arranged adjacent to the second active coating; The first active solid coating is arranged adjacent to the insulating layer; as well as A protective layer is disposed between the first active solid coating and one of the A anode electrodes.

5. The battery pack according to claim 1, wherein the first active solid coating comprises active solid particles that react with lithium.

6. The battery pack according to claim 5, wherein the active solid particles are selected from Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 0.33 La 0.56 TiO3(LLTO), Si, Sn, Li2S-P2S5-GeS2 system, Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 .

7. The battery pack according to claim 6, wherein the particle size of the active solid particles is 10 to 1000 nanometers.

8. The battery pack according to claim 5, wherein the thickness of the first active solid coating is 1 μm to 10 μm.

9. The battery pack according to claim 1, wherein the protective layer comprises a polymer selected from polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO).

10. The battery pack according to claim 9, wherein the protective layer has a thickness of 1 μm to 5 μm.

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