Battery device, power utilization device and energy storage device

Abstract

The utility model discloses a battery device, a power utilization device and an energy storage device. The utility model discloses a battery device box body and a battery monomer assembly. A containing space is formed in the box body. The battery monomer assembly is located in the accommodating space, the battery monomer assembly comprises a buffer component and a plurality of arranged battery monomers, the buffer component is clamped between two adjacent battery monomers, and a buffer gap is formed between the buffer component and the battery monomers. A closed cavity is formed in the buffer component and filled with gas. When the battery monomers are expanded, the buffer parts and the cavities are used for absorbing the expansion of the battery monomers so as to reduce the extrusion force between the two adjacent battery monomers, so that the probability of cracking of the pole pieces in the battery monomers can be reduced, and the working reliability and safety of the battery monomers are improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery device, an electrical device and an energy storage device. Background Art

[0002] At present, when the battery cells in the battery have problems such as overcharging or thermal runaway, the battery cells will expand, causing the battery cells to squeeze each other, which may easily cause the pole pieces in the battery cells to crack, resulting in performance degradation of the battery cells or thermal runaway and other hazards. Utility Model Content

[0003] In view of the above problems, the present application provides a battery device, an electrical device and an energy storage device, which can improve the situation where the battery cells in the battery device are squeezed against each other and cause the pole pieces to crack when the battery cells expand.

[0004] In a first aspect, the present application provides a battery device, comprising

[0005] A box body, wherein the interior of the box body has a containing space;

[0006] The battery cell assembly is located in the accommodating space. The battery cell assembly includes a buffer component and a plurality of arranged battery cells. A buffer component is sandwiched between two adjacent battery cells. A buffer gap is provided between the buffer component and the battery cells. The interior of the buffer component has a closed cavity filled with gas.

[0007] When the battery cell expands, the buffer gap between the buffer component and the battery cell can absorb the expansion of the battery cell to reduce the squeezing force between two adjacent battery cells. When the volume between two adjacent battery cells expands too much, the buffer gap cannot completely absorb the expanded part of the battery cell, causing the buffer component to be squeezed, and the squeezing force between the two adjacent battery cells will gradually increase, causing the cavity to be squeezed, so that the buffer component further absorbs the expansion of the battery cell, thereby reducing the squeezing force between the two adjacent battery cells, so as to reduce the probability of the pole piece being squeezed and broken.

[0008] In some embodiments, the surface of the buffer component facing the battery cell has a concave surface.

[0009] When the battery cell expands, it generally has an outwardly convex curved surface. The buffer component is set as an inwardly concave surface, which can accommodate the expanded part of the battery cell to reduce the extrusion force of the battery cell, thereby reducing the probability of the pole piece being squeezed and broken.

[0010] In some embodiments, the concave surface is a concave curved surface.

[0011] The concave curved surface can better adapt to the expanded portion of the battery cell to accommodate the expanded portion of the battery cell, thereby reducing the squeezing force on the battery cell.

[0012] In some embodiments, the cavity has a first wall, a buffer gap is formed between the first wall and the battery cell, and the first wall is configured to bend and deform when the battery cell expands.

[0013] Therefore, when the battery cell expands, the first wall body can be bent to further absorb the expansion deformation of the battery cell, thereby better accommodating the expanded part of the battery cell and reducing the squeezing force on the battery cell.

[0014] In some embodiments, a wall adjacent to the first wall in the cavity has a support structure.

[0015] The provision of the support structure can improve the rigidity of the wall body adjacent to the first wall body in the buffer component, reduce the probability of being squeezed and deflected by the battery cell during the expansion of the battery cell, and thus improve the reliability of the work.

[0016] In some embodiments, a support structure is disposed around the cavity.

[0017] Thus, the rigidity of the peripheral wall adjacent to the first wall in the buffer component can be improved, so that the first wall is sandwiched between the support structure and the battery cell. During the expansion process, the support structure plays a supporting role to reduce the probability of being squeezed and deflected by the battery cell.

[0018] In some embodiments, the buffer component includes a pressure relief component, the cavity has a second wall, the second wall is arranged adjacent to the first wall, the second wall has a pressure relief component, and the pressure relief component opens when the cavity reaches a set pressure to release the gas in the cavity.

[0019] When the expansion force of two adjacent battery cells is too large, the pressure relief component opens when the cavity reaches a set pressure to discharge the gas in the cavity, thereby further buffering the battery cells to reduce the force of mutual squeezing between the two adjacent battery cells, thereby reducing the probability of electrode breakage.

[0020] In some embodiments, the pressure relief component includes a weak area disposed on the second wall, and the weak area is configured to be destroyed when the cavity reaches a set pressure to release the gas in the cavity.

[0021] When the squeezing force of the battery cell on the buffer component exceeds the set value, the pressure relief component reaches the set pressure to release the gas in the cavity, thereby reducing the force of the battery cell on the buffer component, so as to better control the squeezing force on the battery cell during expansion, further reduce the probability of fracture of the pole piece in the battery cell, and improve the safety of the battery cell.

[0022] In some embodiments, the battery cell includes a shell and an electrode terminal, the shell is provided with an electrode terminal on a first side along a first direction, the buffer component has a pressure relief component on a first side along the first direction, and the first direction is the same as or intersects with the height direction of the box.

[0023] During installation, a certain distance needs to be set between the electrode terminal and the box body. The pressure relief component and the electrode terminal are set in the same direction to facilitate the exhaust of the cavity when the pressure relief component is opened, so as to reduce the probability of the pressure relief component being blocked.

[0024] In some embodiments, a buffer gap is provided between a wall with the largest area in the housing and the buffer component.

[0025] When the battery cell expands, the wall with the largest area in the shell will produce greater deformation and be subjected to greater extrusion pressure. Therefore, setting the buffer component on the wall with the largest area in the shell can reduce the probability of pole piece breakage, thereby improving the reliability and safety of the battery cell operation.

[0026] In some embodiments, the cushioning component is thermal insulation.

[0027] When the temperature of a battery cell is too high, such as in thermal runaway of the battery cell, the buffer component can reduce the heat transfer between two adjacent battery cells, thereby reducing the impact of the battery cell with too high temperature on the adjacent battery cell with lower temperature, thereby improving the safety of the battery cell.

[0028] In some embodiments, a battery cell includes a housing and electrode terminals;

[0029] Electrode terminals are provided on the surface facing the side wall of the shell, at least a part of the battery cells are arranged along the height direction of the shell, and buffer components are provided for two adjacent battery cells arranged along the height direction of the shell, or the electrode terminals are located at the top or the bottom of the shell, and the arrangement direction of the multiple battery cells intersects with the height direction of the shell.

[0030] The buffer component can be set along the height direction of the box body, or along a direction intersecting the height direction of the box body. Specifically, it can be arranged between two adjacent battery cells according to the arrangement of the battery cells to alleviate the extrusion force on the battery cells when the battery cells expand, thereby improving the fracture of the pole pieces inside the battery cells.

[0031] In a second aspect, the present application provides an electrical device, comprising the battery device of the first aspect, wherein the battery device is used to provide electrical energy to the electrical device.

[0032] Since the electrical device includes all the technical features of the battery device of the first aspect, the effects are the same as those described above and will not be described in detail here.

[0033] In a third aspect, the present application provides an energy storage device, including a cabinet and a battery cluster. The battery cluster is accommodated in the cabinet, and the battery cluster includes a plurality of battery devices according to the second aspect.

[0034] Since the energy storage device includes all the technical features of the battery device of the first aspect, the effects are the same as those described above and will not be described in detail here.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0037] Figure 1 An exploded diagram of a battery device according to an embodiment of the present application;

[0038] Figure 2 An exploded view of a battery cell according to an embodiment of the present application;

[0039] Figure 3 A partial cross-sectional view of a battery device in which a buffer component is sandwiched between two adjacent battery cells in an embodiment of the present application, wherein the cross-sectional plane is parallel to the arrangement direction of the battery cells and the height direction of the buffer component;

[0040] Figure 4 This is an isometric view of a buffer component in a battery device according to an embodiment of the present application;

[0041] Figure 5 A structural diagram of a vehicle in which an electric device according to an embodiment of the present application is used;

[0042] Figure 6 This is an axonometric diagram of an energy storage device according to an embodiment of the present application.

[0043] The reference numerals in the specific implementation manner are as follows:

[0044] 1000. Vehicles;

[0045] 100. Battery device;

[0046] 10. Box body; 11. First box body; 12. Second box body;

[0047] 20. Battery cell assembly; 21. Battery cell; 211. Housing; 2111. End cap; 21111. Electrode terminal; 2112. Housing; 212. Electrode assembly; 214. Current collecting member; 22. Buffer component; 221. Cavity; 222. First wall; 223. Second wall; 224. Inner concave surface; 225. Support structure; 226. Pressure relief component; 23. Buffer gap;

[0048] 2000, energy storage device; 2100, cabinet; 2200, battery cluster;

[0049] Z, height direction. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0057] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0058] At present, when the battery cells in the battery have problems such as overcharging or thermal runaway, the battery cells will expand, causing the battery cells to squeeze each other, making the pole pieces in the battery cells easy to break. The broken pole pieces can easily cut the diaphragm in the battery cells, making the battery cells prone to risks such as thermal runaway or short circuit.

[0059] In view of this, the present application provides a battery device, in which when the battery cell expands, the buffer gap between the buffer component and the battery cell can absorb the expansion of the battery cell to reduce the squeezing force between two adjacent battery cells. When the volume between two adjacent battery cells expands too much, the buffer gap cannot completely absorb the expanded part of the battery cell, causing the buffer component to be squeezed, and the squeezing force between the two adjacent battery cells will gradually increase, causing the cavity to be squeezed, so that the buffer component further absorbs the expansion of the battery cell, thereby reducing the squeezing force between the two adjacent battery cells, reducing the probability of the pole piece being squeezed and broken, and improving the safety of the battery device.

[0060] For the convenience of explanation, please refer to the following examples. Figure 1-Figure 4 , a battery device 100 according to some embodiments of the present application is taken as an example for description.

[0061] The battery device 100 includes a box body 10 and a battery cell assembly 20. The box body 10 has a storage space inside. The battery cell assembly 20 is located in the storage space, and the battery cell assembly 20 includes a buffer component 22 and a plurality of arranged battery cells 21. A buffer component 22 is sandwiched between two adjacent battery cells 21, and a buffer gap 23 is provided between the buffer component 22 and the battery cells 21. The buffer component 22 has a closed cavity 221 inside, and the cavity 221 is filled with gas.

[0062] The material of the buffer component 22 can be a material with a certain elasticity, such as aerogel, polypropylene or polyethylene.

[0063] The battery cell 21 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0064] The number of the battery cell assembly 20 may be one or more.

[0065] The plurality of battery cells 21 in the battery cell assembly 20 may be connected in series, in parallel, or in mixed series via a busbar.

[0066] The battery cell assembly 20 is generally formed by arranging a plurality of battery cells 21. As an example, the battery cell assembly 20 may be a battery module, which is formed by arranging and fixing a plurality of battery cells 21 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 21 with a cable tie.

[0067] As an example, the battery cell assembly 20 may be a battery module, and the battery cell assembly 20 may be accommodated in the box body 10 by fixing the battery module in the box body 10 .

[0068] As an example, the battery cell assembly 20 may also be accommodated in the case 10 by directly fixing the plurality of battery cells 21 to the case 10 .

[0069] As an example, the box 10 may include a first box 11 and a second box 12. The first box 11 and the second box 12 are buckled together to form a closed space inside the box 10 to accommodate the battery cell assembly 20. The closed here means covered or closed, which can be sealed or unsealed. The first box 11 can be a top cover or a bottom plate. As an example, the box 10 may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box 10 to accommodate the battery cell assembly 20.

[0070] When the battery cell 21 expands, the buffer gap 23 between the buffer component 22 and the battery cell 21 can absorb the expansion of the battery cell 21 to reduce the squeezing force between two adjacent battery cells 21. When the volume between two adjacent battery cells 21 expands too much, the buffer gap 23 cannot completely absorb the expanded part of the battery cell 21, so that the buffer component 22 is squeezed, and the squeezing force between the two adjacent battery cells 21 will gradually increase, so that the cavity 221 is squeezed, so that the buffer component 22 further absorbs the expansion of the battery cell 21, thereby reducing the squeezing force between the two adjacent battery cells 21, so as to reduce the probability of the pole piece being squeezed and broken.

[0071] The battery cell 21 generally includes an electrode assembly 212. The electrode assembly 212 includes a positive electrode, a negative electrode, and a separator, and the separator is arranged between the negative electrode and the positive electrode. During the charge and discharge process of the battery cell 21, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time allow active ions to pass through.

[0072] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0073] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0074] As an example, the positive electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium or silver, etc., may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0075] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2) and at least one of its modified compounds. The modified compound refers to a substance obtained by modifying the above substances by means of doping or coating.

[0076] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a foamed nickel, a foamed copper, a foamed aluminum, a foamed alloy, or a foamed carbon. When the foamed metal is used as the positive electrode, the positive electrode active material may not be disposed on the surface of the foamed metal, but of course, the positive electrode active material may also be disposed. As an example, the positive electrode active material is filled or / and deposited in the foamed metal.

[0077] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0078] As an example, the negative electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium or silver, etc., may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0079] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0080] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0081] As an example, the negative electrode active material may adopt the negative electrode active material for the battery cell 21 known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for the battery cell 21 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0082] In some embodiments, the negative electrode may be a foam metal. The foam metal may be foam nickel, foam copper, foam aluminum, foam alloy, or foam carbon, etc. When the foam metal is used as the negative electrode sheet, the surface of the foam metal may not be provided with a negative electrode active material, but of course, a negative electrode active material may also be provided.

[0083] As an example, a negative electrode active material may be filled and / or deposited in the negative electrode current collector.

[0084] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0085] In some embodiments, the electrode assembly 212 further includes a separator disposed between the positive electrode and the negative electrode.

[0086] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0087] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be coated on the surface of the separator.

[0088] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0089] In some embodiments, the battery cell 21 further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0090] The liquid electrolyte includes an electrolyte salt and a solvent.

[0091] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0092] In certain embodiments, solvent can be selected from ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1, at least one of 4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. Solvent can also be selected from ether solvents. Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0093] In some embodiments, the electrolyte may also optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell 21, such as additives that improve the overcharge / fast charge performance of the battery cell 21, additives that improve the high temperature performance of the battery cell 21, and additives that improve the low temperature performance of the battery cell 21.

[0094] Among them, the gel electrolyte includes a polymer as a skeleton network and can be used in combination with an ionic liquid-lithium salt.

[0095] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0096] As examples, the polymer of the polymer solid electrolyte may include polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, a polyionic liquid, cellulose, and the like.

[0097] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0098] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0099] The electrode assembly 212 may be a wound structure, a laminated structure, or a mixed structure of a wound structure and a laminated structure.

[0100] In some embodiments, the electrode assembly 212 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0101] In some embodiments, the electrode assembly 212 is a laminate structure.

[0102] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0103] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0104] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0105] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0106] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0107] In some embodiments, the shape of the electrode assembly 212 can be cylindrical, flat, or polygonal.

[0108] In some embodiments, the electrode assembly 212 is provided with tabs, which can conduct current from the electrode assembly 212. The tabs include a positive tab and a negative tab.

[0109] In some embodiments, please refer to Figure 3 and Figure 4 The surface of the buffer component 22 facing the battery cell 21 has an inner concave surface 224 .

[0110] The concave surface 224 can be a concave curved surface or a flat surface. For example, a groove is provided on the surface of the buffer component 22 facing the battery cell 21, and the bottom wall of the groove serves as the concave surface 224, which can be a flat surface. The contour shape of the notch of the groove can be rectangular, circular or elliptical, etc. It can be designed according to actual needs and is not specifically limited in this application.

[0111] When the battery cell 21 expands, it generally has an outwardly convex curved surface. The buffer component 22 is configured as an inner concave surface 224 to accommodate the expanded portion of the battery cell 21 to reduce the squeezing force of the battery cell 21, thereby reducing the probability of the electrode being squeezed and broken.

[0112] In some embodiments, the inner concave surface 224 is a concave curved surface.

[0113] The concave surface 224 includes but is not limited to a concave spherical surface, a parabolic surface, or an ellipsoidal surface.

[0114] The concave curved surface can better adapt to the expanded portion of the battery cell 21 to accommodate the expanded portion of the battery cell 21 , thereby reducing the squeezing force on the battery cell 21 .

[0115] In some embodiments, please refer to Figure 3 The cavity 221 has a first wall 222 , and a buffer gap 23 is defined between the first wall 222 and the battery cell 21 . The first wall 222 is configured to bend and deform when the battery cell 21 expands.

[0116] The material of the first wall 222 may be, but is not limited to, polytetrafluoroethylene, nylon, or polyurethane.

[0117] The cavity 221 may be filled with a non-flammable gas, for example, the gas in the cavity 221 may be, but is not limited to, nitrogen, carbon dioxide, or a rare gas, etc. The rare gas may be, but is not limited to, argon or helium, etc.

[0118] The shape of the cavity 221 is not specifically limited and can be designed according to actual needs.

[0119] Therefore, when the battery cell 21 expands, the first wall 222 can be bent to further absorb the expansion deformation of the battery cell 21 , thereby better accommodating the expanded portion of the battery cell 21 and reducing the squeezing force on the battery cell 21 .

[0120] In some embodiments, please refer to Figure 3 and Figure 4 The buffer component 22 includes a pressure relief component 226. The cavity 221 has a second wall 223. The second wall 223 is arranged adjacent to the first wall 222. The second wall 223 has a pressure relief component 226. The pressure relief component 226 opens when the cavity 221 reaches a set pressure to release the gas in the cavity 221.

[0121] The pressure relief component 226 may be an active valve that is actively opened at a set pressure, or a passive valve that is opened by pressure at a set pressure. For example, a pressure sensor may be provided in the cavity 221, and the pressure sensor may be used to detect the pressure, and the valve opening may be actively controlled by determining whether the set pressure is reached by the pressure, such as when the pressure relief component 226 is a solenoid valve. The pressure relief component 226 may also be, but is not limited to, a relief valve, a one-way throttle valve, or a pressure sequence valve.

[0122] When the expansion force of two adjacent battery cells 21 is too large, the pressure relief component 226 reaches a set pressure in the cavity 221, causing the pressure relief component 226 to open to discharge the gas in the cavity 221, thereby further buffering the battery cells 21 to reduce the force of mutual squeezing between the two adjacent battery cells 21, thereby reducing the probability of electrode breakage.

[0123] In some embodiments, please refer to Figure 3 and Figure 4 The pressure relief component 226 includes a weak area arranged on the second wall 223 , and the weak area is configured to be destroyed when the cavity 221 reaches a set pressure to release the gas in the cavity 221 .

[0124] As an example, a weak area can be formed on the second wall 223 by providing a notch or a groove on the second wall 223. For example, an annular notch can be provided on the second wall 223, and when the set pressure is reached in the cavity 221, the area within the annular notch is destroyed, so that the gas in the cavity 221 is released. The notch can also be, but not limited to, an H-shaped notch, which can be specifically provided according to actual needs and is not specifically limited here. In another example, a pressure relief hole can be provided on the second wall 223, and the pressure relief hole is sealed with a film. When the pressure in the cavity 221 reaches the set pressure, the film is first destroyed, so that the gas in the cavity 221 is released.

[0125] When the squeezing force of the battery cell 21 on the buffer component 22 exceeds the set value, the pressure relief component 226 reaches the set pressure to release the gas in the cavity 221, thereby reducing the force of the battery cell 21 on the buffer component 22, so as to better control the squeezing force on the battery cell 21 during expansion, further reduce the probability of fracture of the pole piece in the battery cell 21, and improve the safety of the battery cell 21.

[0126] In some embodiments, please refer to Figure 3 The wall adjacent to the first wall 222 in the cavity 221 has a support structure 225.

[0127] As an example, the material of the frame may be, but is not limited to, fiberglass material or structural adhesive, etc. The support structure 225 may also be a support plate or a support rib, and the support structure 225 may be disposed on two side walls adjacent to the first wall 222 in the cavity 221, or on the top wall or bottom wall adjacent to the first wall 222 in the cavity 221.

[0128] The provision of the support structure 225 can improve the rigidity of the wall adjacent to the first wall 222 in the buffer component 22 , and reduce the probability of being squeezed and deflected by the battery cell 21 during the expansion of the battery cell 21 , thereby improving the reliability of the operation.

[0129] In some embodiments, please refer to Figure 3 , the support structure 225 is arranged around the cavity 221.

[0130] As an example, the support structure 225 is disposed around the cavity 221 and forms a frame. The frame may be, but is not limited to, a circular frame or a polygonal frame.

[0131] As an example, the buffer component 22 can be surrounded by multiple plates and manufactured into a structure having a cavity 221 by bonding, injection molding or welding, and the frame can be set in the cavity 221 and fixed to the plate by bonding to form an integrated structure. The setting of the support structure 225 can improve the rigidity of the buffer component 22 around, so as to facilitate the fixation with the battery cell 21, reduce the probability of the buffer component 22 being squeezed by the battery cell 21 and deviating during operation, thereby improving the reliability of operation.

[0132] In this way, the stiffness of the peripheral wall adjacent to the first wall 222 in the buffer component 22 can be improved, so that the first wall 222 is sandwiched between the support structure 225 and the battery cell 21. During the expansion process, the support structure 225 plays a supporting role to reduce the probability of being squeezed and deflected by the battery cell 21.

[0133] In some embodiments, please refer to Figure 2 The battery cell 21 includes a housing 211 and an electrode terminal 21111. The housing 211 is provided with an electrode terminal 21111 on a first side along a first direction. The buffer component 22 is provided with a pressure relief component 226 on a first side along the first direction. The first direction is the same as or intersects with a height direction Z of the housing 10.

[0134] Figure 1 The example shows that the top of the housing 211 is provided with an electrode terminal 21111, and the top of the buffer component 22 is provided with a pressure relief component 226, that is, the first direction is the same as the height direction Z of the box 10. In another example, the bottom of the housing 211 may be provided with an electrode terminal 21111, and the bottom of the buffer component 22 may be provided with a pressure relief component 226. In another example, the first side of the housing 211 facing the side wall of the box 10 may be provided with an electrode terminal 21111, and the first side of the buffer component 22 facing the side wall of the box 10 may be provided with a pressure relief component 226, and the first direction may intersect with the height direction Z of the box 10.

[0135] The housing 211 may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing 211), or an aluminum-plastic film. The housing 211 may be a sealed structure or a non-sealed structure. As an example, when the housing 211 is a non-sealed structure, the housing 211 plays a role in protecting the electrode assembly 212, and a sealed bag is also included between the housing 211 and the electrode assembly 212, and the sealed bag is used to encapsulate the electrode assembly 212 and the electrolyte. Specifically, the sealed bag may be a bag-shaped insulating member or an aluminum-plastic film. When the housing 211 is a sealed structure, it is used to encapsulate components such as the electrode assembly 212 and the electrolyte.

[0136] As an example, the housing 211 may include an end cap 2111 and a shell 2112, wherein the shell 2112 is provided with an opening, and the end cap 2111 is provided to cover the opening. The shell 2112 may be provided with one or more openings. One or more end caps 2111 may also be provided.

[0137] The electrode terminal 21111 may be directly connected to the electrode tab, or may be indirectly connected to the electrode tab via the current collecting member 214. The electrode terminal 21111 may be disposed on the end cap 2111, or may be disposed on the housing 2112.

[0138] During installation, the electrode terminal 21111 needs to be set at a certain distance from the box body 10. The pressure relief component 226 and the electrode terminal 21111 are set in the same direction, which can facilitate the exhaust of the cavity 221 when the pressure relief component 226 is opened, so as to reduce the probability of the pressure relief component 226 being blocked.

[0139] In some embodiments, please refer to Figure 3 A buffer gap 23 is provided between the wall with the largest area in the housing 211 and the buffer component 22 .

[0140] When the battery cell 21 expands, the wall with the largest area in the shell 211 produces a larger deformation and is subjected to a larger extrusion force. Therefore, setting the buffer component 22 on the wall with the largest area in the shell 211 can reduce the probability of the electrode piece breaking, thereby improving the reliability and safety of the battery cell 21.

[0141] In some embodiments, cushioning component 22 is a thermal insulator.

[0142] The heat insulating member may be, but is not limited to, a polyethylene foam board, a polytetrafluoroethylene board or a polyurethane board.

[0143] When the temperature of a battery cell 21 is too high, such as when the battery cell 21 is in thermal runaway, the buffer component 22 can reduce the heat transfer between two adjacent battery cells 21 to reduce the impact of the battery cell 21 with too high a temperature on the adjacent battery cell 21 with lower temperature, thereby improving the safety of the battery cell 21.

[0144] In some embodiments, the battery cell 21 includes a housing 211 and an electrode terminal 21111. The surface of the housing 211 facing the side wall of the box body 10 is provided with an electrode terminal 21111, at least part of the battery cells 21 are arranged along the height direction Z of the box body 10, and two adjacent battery cells 21 arranged along the height direction Z of the box body 10 are provided with a buffer component 22; or, please refer to Figure 1 The electrode terminal 21111 is located at the top of the outer shell 211 or the bottom of the outer shell 211 , and the arrangement direction of the plurality of battery cells 21 intersects with the height direction Z of the box body 10 .

[0145] The housing 211 may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing 211 ), or an aluminum-plastic film.

[0146] The buffer component 22 can be set along the height direction Z of the box body 10, or along the direction intersecting the height direction Z of the box body 10. Specifically, it can be arranged between two adjacent battery cells 21 according to the arrangement of the battery cells 21 to alleviate the squeezing force on the battery cell 21 when the battery cell 21 expands, thereby improving the fracture of the pole piece inside the battery cell 21.

[0147] In some embodiments, the housing 211 may be a sealed structure or a non-sealed structure. As an example, when the housing 211 is a non-sealed structure, the housing 211 plays a role in protecting the electrode assembly 212, and a sealed bag is also included between the housing 211 and the electrode assembly 212, and the sealed bag is used to encapsulate the electrode assembly 212 and the electrolyte. Specifically, the sealed bag can be a bag-shaped insulating member or an aluminum-plastic film. When the housing 211 is a sealed structure, it is used to encapsulate the electrode assembly 212, the electrolyte and other components.

[0148] The housing 211 includes an end cap 2111 and a shell 2112. The shell 2112 is provided with an opening, and the end cap 2111 is provided to cover the opening. The shell 2112 may be provided with one or more openings. One or more end caps 2111 may also be provided.

[0149] For the convenience of description, the following embodiments are described by taking an electrical device of some embodiments of the present application as an example.

[0150] The electric device includes the battery device 100 of the above embodiment, and the battery device 100 is used to provide electric energy to the electric device.

[0151] Please refer to Figure 5 The box 10 can be used as a part of the chassis structure of the vehicle 1000. For example, part of the box 10 can become at least a part of the floor of the vehicle 1000, or part of the box 10 can become at least a part of the cross beam and the longitudinal beam of the vehicle 1000.

[0152] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery cells 21, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles 1000, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0153] Since the electrical device includes all the technical features of the battery device 100 of the above embodiment, the effects are the same as above and will not be described in detail here.

[0154] For the convenience of description, the following embodiments are described by taking an energy storage device 2000 of some embodiments of the present application as an example.

[0155] The energy storage device 2000 includes a cabinet 2100 and a battery cluster 2200 . The battery cluster 2200 is accommodated in the cabinet 2100 . The battery cluster 2200 includes a plurality of battery devices 100 according to the above embodiments.

[0156] The battery cluster 2200 can improve the voltage and capacity of the energy storage device 2000. The battery cluster 2200 may include a plurality of battery devices 100. The plurality of battery devices 100 are connected in series through a busbar to improve the voltage of the energy storage device 2000. When the energy storage device 2000 includes a plurality of battery clusters 2200, the plurality of battery clusters 2200 are connected in parallel to improve the capacity of the energy storage device 2000.

[0157] The energy storage device 2000 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems or temporary power supply systems. The energy storage device 2000 can store electrical energy as needed and output electrical energy at an appropriate time. For example, the energy storage device 2000 can store electrical energy during low power consumption and provide electrical energy to relevant users or electrical equipment during peak power consumption. The energy storage system provided in the embodiment of the present application can be any power system that requires the use of the energy storage device 2000.

[0158] In some embodiments, the energy storage device 2000 is an energy storage container or an energy storage cabinet.

[0159] Since the energy storage device 2000 includes all the technical features of the battery device 100 of the above embodiment, the effects are the same as above and will not be described in detail here.

[0160] In an alternative embodiment of the battery device 100, please refer to Figure 1-Figure 4The battery device 100 includes a housing 10 and a battery cell assembly 20. The housing 10 has a storage space inside. The battery cell assembly 20 is located in the storage space. The battery cell assembly 20 includes a buffer component 22 and a plurality of arranged battery cells 21. A buffer component 22 is sandwiched between two adjacent battery cells 21. A buffer gap 23 is provided between the buffer component 22 and the battery cell 21. The surface of the buffer component 22 facing the battery cell 21 has an inner concave surface 224, and the inner concave surface 224 is an inner concave curved surface. The interior of the buffer component 22 has a closed cavity 221, and the cavity 221 is filled with gas. The cavity 221 has a first wall 222, and a buffer gap 23 is provided between the first wall 222 and the battery cell 21. The first wall 222 is configured to be able to bend and deform when the battery cell 21 expands. The buffer component 22 includes a pressure relief component 226. The cavity 221 has a second wall 223, which is disposed adjacent to the first wall 222. The second wall 223 has a pressure relief component 226. The pressure relief component 226 opens when the cavity 221 reaches a set pressure to release the gas in the cavity 221. The pressure relief component 226 includes a weak area disposed on the second wall 223, which is disposed to be destroyed when the cavity 221 reaches a set pressure to release the gas in the cavity 221. The battery cell 21 includes a housing 211 and an electrode terminal 21111. The top of the housing 211 is provided with an electrode terminal 21111. The top of the buffer component 22 has a pressure relief component 226. A buffer gap 23 is provided between the wall with the largest area in the housing 211 and the buffer component 22. The wall adjacent to the first wall 222 in the cavity 221 has a support structure 225, which is disposed around the cavity 221. The buffer component 22 is a heat insulating component. The electrode terminal 21111 is located at the top of the housing 211 or the bottom of the housing 211 , and the arrangement direction of the plurality of battery cells 21 intersects with the height direction Z of the housing 10 .

[0161] When the battery cell 21 expands, the buffer gap 23 between the buffer component 22 and the battery cell 21 can absorb the expansion of the battery cell 21, and the cavity 221 can make the buffer component 22 have a certain amount of compression to reduce the squeezing force between two adjacent battery cells 21, thereby reducing the probability of cracking of the pole piece in the battery cell 21, so as to improve the reliability and safety of the battery cell 21. When the expansion force of the battery cell 21 reaches the set value, the pressure relief component 226 opens to discharge the gas in the cavity 221, which can reduce the squeezing force on the battery cell 21 and improve the safety and reliability of the battery cell 21.

[0162] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: A box body, wherein the interior of the box body has a containing space; A battery cell assembly is located in the accommodating space, and the battery cell assembly includes a buffer component and a plurality of arranged battery cells. The buffer component is sandwiched between two adjacent battery cells, and a buffer gap is provided between the buffer component and the battery cells. The interior of the buffer component has a closed cavity, and the cavity is filled with gas.

2. The battery device according to claim 1, characterized in that: The buffer component has a concave surface on a surface facing the battery cell.

3. The battery device according to claim 2, characterized in that: The concave surface is a concave curved surface.

4. The battery device according to claim 1, characterized in that: The cavity has a first wall, a buffer gap is defined between the first wall and the battery cell, and the first wall is configured to bend and deform when the battery cell expands.

5. The battery device according to claim 4, characterized in that: A wall body in the cavity adjacent to the first wall body has a supporting structure.

6. The battery device according to claim 5, characterized in that: The supporting structure is arranged around the cavity.

7. The battery device according to claim 4, characterized in that: The buffer component includes a pressure relief component. The cavity has a second wall. The second wall is arranged adjacent to the first wall. The second wall has the pressure relief component. When the cavity reaches a set pressure, the pressure relief component opens to release the gas in the cavity.

8. The battery device according to claim 7, characterized in that: The pressure relief component includes a weak area arranged on the second wall, and the weak area is configured to be destroyed when the cavity reaches a set pressure to release the gas in the cavity.

9. The battery device according to claim 7, characterized in that: The battery cell includes a shell and an electrode terminal. The electrode terminal is disposed on a first side of the shell along a first direction. The buffer component has the pressure relief component on the first side along the first direction. The first direction is the same as or intersects with a height direction of the box.

10. The battery device according to claim 9, characterized in that: The buffer gap is provided between the wall with the largest area in the housing and the buffer component.

11. The battery device according to any one of claims 1 to 10, characterized in that: The buffer component is a heat insulating component.

12. The battery device according to any one of claims 1 to 8, characterized in that: The battery cell comprises a housing and electrode terminals; The electrode terminal is provided on the surface of the outer shell facing the side wall of the box body, at least a part of the battery cells are arranged along the height direction of the box body, and the buffer component is provided on two adjacent battery cells arranged along the height direction of the box body, or the electrode terminal is located at the top of the outer shell or the bottom of the outer shell, and the arrangement direction of the plurality of battery cells intersects with the height direction of the box body.

13. An electrical device, characterized in that: It comprises a battery device as described in any one of claims 1 to 12, wherein the battery device is used to provide electrical energy to the electrical device.

14. An energy storage device, characterized in that: The invention comprises a cabinet and a battery cluster, wherein the battery cluster is accommodated in the cabinet and comprises a plurality of battery devices according to any one of claims 1 to 12.

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