CN220796820U

CN220796820U - Battery module and battery pack

Info

Publication number: CN220796820U
Application number: CN202320436756.5U
Authority: CN
Inventors: 李峥; 范光亮; 王利娜; 冯玉川; 何泓材
Original assignee: Suzhou Qingtao New Energy S&T Co Ltd
Current assignee: Suzhou Qingtao New Energy S&T Co Ltd
Priority date: 2023-03-09
Filing date: 2023-03-09
Publication date: 2024-04-16
Anticipated expiration: 2033-03-09

Abstract

The application belongs to the technical field of batteries, and discloses a battery module and battery pack, battery module is platykurtic setting, and it includes a plurality of electric core, ifThe dry cells are stacked together in a horizontal arrangement to form a cell group, the length L of the cells in a first direction ₁ Length L in the second direction ₂ The relation of (2) is: l is more than or equal to 1.01 ₁ /L ₂ Is less than or equal to 2 percent, length L of the battery cell in the first direction ₁ Length L in the third direction ₃ The relation of (2) is: l (L) ₁ /L ₂ >. 20. The battery module further comprises a support, a buffer piece and a shell, and the complete wrapping and fixing of the battery cell group are achieved through the cooperation of the components. The battery pack comprises the battery module and the liquid cooling structure, and the liquid cooling structure is arranged below the battery module, so that the internal space of the battery pack can be further saved, and the battery pack can be matched with the horizontal placement of the battery cell to realize rapid heat dissipation.

Description

Battery module and battery pack

Technical Field

The application relates to the technical field of batteries, in particular to a battery module and a battery pack.

Background

As new energy electric vehicles market and technology trend to be mature, various vehicle enterprises have more and more investment in new energy electric vehicles. At present, the height of the chassis of the passenger car is different along with the different types of the passenger car, and the height or the height of the chassis of the passenger car are good or bad, for example, the high chassis has good trafficability for various road conditions and cannot damage the chassis; the chassis is low in gravity center, good in vehicle body stability, capable of improving tire grip, reducing air resistance and reducing power loss.

In the prior art, the installation space reserved for the battery pack of the new energy electric automobile with high chassis is larger than the installation space reserved for the battery pack of the new energy electric automobile with low chassis, so that the battery pack of the new energy electric automobile with high chassis cannot be applied to the new energy electric automobile with low chassis, and further, the battery pack needs to be redesigned and produced when the new energy electric automobile with low chassis is produced by a vehicle enterprise, and further, the production cost of the vehicle enterprise is increased.

Therefore, the above-described problems are to be solved.

Disclosure of Invention

The utility model aims at providing a battery module and battery package to satisfy the new forms of energy electric automobile of different chassis heights and to the requirement of battery package, thereby reduce the manufacturing cost of train enterprise.

To achieve the purpose, the application adopts the following technical scheme:

in a first aspect, the present application provides a battery module, where the battery module is disposed in a flat shape;

the battery module comprises a plurality of battery cells, and the battery cells are stacked together in a horizontal placement mode to form a battery cell group; it should be noted that the horizontal placement herein means that the thickness direction of the battery cell is in the vertical direction;

taking the thickness direction of the battery cell as a third direction, wherein the third direction is perpendicular to the first direction and the second direction respectively; the first direction is perpendicular to the second direction;

due to the thickness of the cell, it is also defined in this application as the length L of the cell in the third direction ₃ The length of the single battery cell in the first direction, the second direction and the third direction is minimum, the height of the battery module in the third direction can be greatly saved in a horizontal stacking mode, the height of the whole battery pack is reduced, and the adaptability of the battery pack to a new energy automobile with a lower chassis and a small in vehicle-interior space is improved.

It will be appreciated that since the battery pack is horizontally disposed in the electric vehicle, in some embodiments, the first direction is the length direction of the vehicle, and in other embodiments, the second direction is the width direction of the vehicle, and in other embodiments, the first direction is the width direction of the vehicle, and the second direction is the length direction of the vehicle.

The length of the battery cell in the first direction is L ₁ Length in the second direction is L ₂ L is then ₁ And L ₂ The following relationship exists: l is more than or equal to 1.01 ₁ /L ₂ The purpose of setting is less than or equal to 2, adopts the mode that a plurality of electric cores are stacked horizontally to carry out electric core group based on this application, exists the interaction force between the monomer electric core, and in addition, along the third direction, because gravity effect, the monomer electric core that is located above applys certain pressure to the monomer electric core that is located below, in order to guarantee the normal work of the electric core that is close to new energy automobile chassis one side, L ₁ /L ₂ The reduction of the ratio is beneficial to relieving the pressure and effectively preventing the pressureOr expansion, etc., and the performance of the cell deteriorates.

In a preferred embodiment, L ₁ And L ₂ The following relationship exists: l is more than or equal to 1.01 ₁ /L ₂ ≤1.5。

In a preferred embodiment, L ₁ And L ₂ The following relationship exists: l is more than or equal to 1.01 ₁ /L ₂ ≤1.1。

The length of the battery cell in the first direction is L ₁ Length in the third direction is L ₃ And L is ₁ And L ₃ The following relationship exists: l (L) ₁ /L ₃ > 20, with L ₁ /L ₃ The ratio is increased, so that more battery cells can be stacked under the requirement of fixed length in the third direction, and the capacity performance and the endurance time of the battery pack are improved.

In one embodiment, the length of the battery cell in the first direction is L ₁ Length in the third direction is L ₃ And L is ₁ And L ₃ The following relationship exists: l (L) ₁ /L ₃ ＜100。

In one embodiment, the single cell is a soft pack cell.

In one embodiment, the soft package battery core comprises a bare battery core prepared from a positive electrode, a negative electrode, a diaphragm and/or a solid electrolyte membrane through lamination or winding process, and an aluminum-plastic film arranged on the outer side of the bare battery core, wherein the bare battery core is placed in a pit where the aluminum-plastic film is punched in advance, and the soft package battery core is formed through high-temperature heat sealing.

In one embodiment, the single battery cell extends along a first direction to lead out a tab, including a positive tab and a negative tab.

In another embodiment, the single battery cell extends along the second direction to lead out a tab, including a positive tab and a negative tab.

Further, the positive and negative tabs are located on either side of the cell in some embodiments, and on the same side of the cell in other embodiments.

In one embodiment, the battery cells in the battery module are connected in series. At this time, the pole ear of each single electric core is opposite to the pole ear led out from the same side of the two adjacent electric cores, and when the pole ear of one single electric core on the side is an anode pole ear, the pole ears of the upper electric core and the lower electric core on the corresponding positions on the side are cathode pole ears, and the use of the collection wiring harness is further reduced through the welded connection of the pole ears, so that the residual space of the battery module except the electric cores is saved.

In one embodiment, the number of the battery cells stacked in the third direction in the battery module is L, and L is less than or equal to 30.

In one embodiment, the battery module further comprises a buffer member disposed between the unit cells for buffering the pressure received by the unit cells and absorbing expansion of the unit cells due to the increase of the charge and discharge times.

In one embodiment, the cushioning member includes a cushioning structure and adhesive layers disposed on both sides thereof.

In a preferred embodiment, the buffer member connects the cell closest to the housing in the third direction to the housing by gluing, connects the cell closest to the housing in the third direction to the housing cover, and fixes adjacent cells together. The single battery cell is horizontally stacked, the structure of the single battery cell has certain stability, and the single battery cell is fixed together through the buffer part, so that the use of a supporting component, a fixing component and the like can be further saved, and the internal space of the battery is further saved.

In one embodiment, the cushioning member is compressed foam.

In one embodiment, the battery module further includes: and the bracket is further positioned at one side of the single battery cell leading-out tab. The total output tab passes through the bracket. Still further, the support can the joint at the plastic-aluminum membrane edge of electric core group, helps fixed electric core group.

In order to further reduce the weight of the battery module, the bracket may be made of plastic materials.

In one embodiment, the battery module further includes: and the end cover is welded with the lug. The end cover and the support are positioned on the same side, and the end cover is made of plastic materials.

In one embodiment, the battery module further comprises a housing, the battery module being carried within the housing; the shell comprises cover plates positioned on two sides of the battery cell group along the third direction, the battery cell group comprises an upper cover plate and a lower cover plate, and the battery cell and the cover plates on the outermost side of the battery cell group along the third direction can be fixedly connected through a buffer piece. The cover plate comprises a main body part and an extension part extending along a third direction, the shell further comprises a side plate, the side plate and the extension part of the cover plate are arranged in parallel, the cover plate wraps the side plate through the extension part, and the end plate is connected with the end cover through a clamping connection.

In order to prolong the endurance mileage of the new energy automobile, the aim of lightening the battery pack is to be achieved first, so in one embodiment, the battery module housing is made of an aluminum alloy material.

In one embodiment, the shell of the battery module is fixed together in a welding mode, and the welding stationary phase is higher in bonding strength, better in tightness and lighter in mass compared with the modes of clamping, screwing and the like.

In an embodiment, the housing of the battery module includes an upper housing and a lower housing, and the upper housing and the lower housing may be made of plastic materials, so that an insulating coating layer on the outer side of the battery cell is reduced, and the effect of light weight can be achieved. Further, the upper housing and the lower housing are locked and fixed as one body by bolts, and the bolts are provided in plurality along the peripheral side of the housing.

In one embodiment, a sealing ring is further provided in the battery module, and the sealing ring is configured to seal a gap between the upper case and the lower case.

In one embodiment, the length L of the battery module in the third direction ₁₃ Satisfy L ₁₃ ≤100mm。

In one embodiment, the length L of the battery module in the third direction ₁₃ Satisfy L ₁₃ ≤80mm。

In a second aspect, the present application provides a battery pack comprising a battery module as described above, the battery pack being provided with at least one battery module in a third direction.

In a preferred embodiment, the battery pack is provided with a battery module in the third direction, so that the height of the battery pack in the third direction is further reduced, and the adaptability of the battery pack to a new energy automobile is improved.

In one embodiment, the battery pack further comprises a liquid cooling structure disposed at a bottom position of the battery pack, and the liquid cooling structure is configured to dissipate heat from the battery module. Because the electric core is placed for the level in the battery module among this application, its heat that produces takes away, reduces battery temperature, avoids the emergence of excessive temperature rise.

In one embodiment, the battery pack further comprises a tray and an upper cover, wherein the tray is used for bearing the battery cells, the plurality of battery modules and the high-low voltage connectors, the explosion-proof valve, the BDU and the BMS are installed in the tray, and the upper cover is fixed after the assembly is completed.

The beneficial effects of this application:

1) The battery pack is flat, the battery pack shell structure designed for the battery pack is matched, the height of the battery pack in the third direction can be effectively reduced, and the battery pack can be matched with new energy vehicles of different vehicle types.

2) The battery pack is designed by adopting the battery core, the module and the battery pack, so that the technical problem that the battery pack cannot be obtained in the capacity and the height of the battery pack in the third direction can be effectively solved, and the technical problem that the battery pack has poor cycle life due to the non-module structure can be solved.

Drawings

FIG. 1 is an exploded schematic view of a battery pack provided herein;

fig. 2 is an exploded view of the battery module provided by the present application.

In the figure:

1. a battery module; 11. a cell group; 12. an upper cover plate; 13. a lower cover plate; 14. a side plate; 15. a bracket; 16. an end cap; 17. an end plate;

2. a tray; 3. an upper cover; 4. a liquid cooling structure; 5. and a buffer member.

Detailed Description

The present application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the application and not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present application are shown in the drawings.

In the description of the present application, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

In this application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", etc. azimuth or positional relationship are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of description and simplification of operations, and do not indicate or imply that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

Referring to fig. 1 to 2, according to an aspect of the present application, a battery module is provided, and the battery module is arranged in a flat shape, and the battery module includes a plurality of battery cells, and the plurality of battery cells are stacked together in a horizontal arrangement manner to form a battery cell group 11; it should be noted that the horizontal placement herein means that the thickness direction of the battery cell is in the vertical direction, i.e., the direction from the chassis to the roof of the automobile; in the application, the thickness direction of the battery cell is taken as a third direction, and the third direction is perpendicular to the first direction and the second direction respectively; the first direction and the second direction are perpendicular.

The battery pack is integrated and assembled in a manner of battery core, module and battery pack, so that the height requirement on the new energy automobile chassis is greatly reduced compared with a traditional assembly manner, the safety performance and the cycle life of the battery pack are greatly improved compared with a non-module assembly manner proposed in the latest research direction, and the long-time high-capacity energy output of the battery is ensured. In the related research, in order to further improve the space utilization of the battery pack, a module-free assembly mode is adopted, a square shell battery or a soft package battery core is directly stacked and assembled into the battery pack, when the battery core is used in a small quantity, the capacity is insufficient to meet the requirement of a new energy automobile on the endurance mileage, and when the battery core is used in a large quantity, the upper battery core can deform and lose efficacy on the lower battery core due to the continuous acting force of the upper battery core on the lower battery core, so that the whole battery pack is scrapped, and the large-scale commercial use is not facilitated.

The application firstly adopts a mode of packing a plurality of battery cells into groups to prepare the battery module. The length of the battery cell in the first direction is L ₁ Length in the second direction is L ₂ L is then ₁ And L ₂ The following relationship exists: l is more than or equal to 1.01 ₁ /L ₂ The purpose of setting is less than or equal to 2, adopts the mode that a plurality of electric cores are stacked horizontally to carry out electric core group based on this application, exists the interaction force between the monomer electric core, and in addition, along the third direction, because gravity effect, the monomer electric core that is located above applys certain pressure to the monomer electric core that is located below, in order to guarantee the normal work of the electric core that is close to new energy automobile chassis one side, L ₁ /L ₂ The reduction of the ratio is beneficial to relieving pressure and effectively preventing the performance degradation of the battery cell due to factors such as pressure or expansion.

As an implementation mode, the lengths of the traditional battery cell in the first direction and the second direction are adjusted at the same time, so that the lengths meet the relation, and particularly, the size of the battery cell can be adjusted by adjusting the size of the positive electrode and the negative electrode when the positive electrode and the negative electrode plates are cut.

As another embodiment, only the length of the battery cell in the second direction is increased so as to gradually approach the length dimension in the first direction.

In one embodiment, the length of the cell in the first direction is L ₁ The method meets the following conditions: l is 150mm or less ₁ ≤800mm。

The length of the battery cell in the first direction is L ₁ Length in the third direction is L ₃ And L is ₁ And L ₃ The following relationship exists: l (L) ₁ /L ₃ > 20. With L ₁ /L ₃ The ratio is increased, so that more battery cells can be stacked under the requirement of fixed length in the third direction, and the capacity performance and the endurance time of the battery pack are improved.

In one embodiment, the individual cells are soft-pack cells.

The positive electrode includes a positive electrode current collector, which may be a metal foil, a metal mesh or screen, or a mesh-shaped metal comprising aluminum or any other suitable conductive material known to those skilled in the art, a positive electrode active material layer.

The positive electrode is formed from a plurality of positive electrode active particles comprising one or more transition metal cations, such as manganese (Mn), nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), vanadium (V), and combinations thereof. In some embodiments, the positive electrode electroactive material layer further comprises an electrolyte, such as a plurality of electrolyte particles. The positive electrode active material layer has a thickness of greater than or equal to about 1 μm to less than or equal to about 1000 μm.

The positive electrode active material layer is one of a layered oxide cathode, a spinel cathode, and a polyanion cathode. For example, a layered oxide cathode (e.g., a rock salt layered oxide) comprises one or more lithium-based positive electroactive materials selected from the group consisting of: liCoO ₂ (LCO)，LiNi _x Mn _y Co _1-x-y O ₂ (wherein x is more than or equal to 0 and less than or equal to 1 and y is more than or equal to 0 and less than or equal to 1), liNi _1-x-y Co _x Al _y O ₂ (wherein x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 0 and less than or equal to 1), and LiNi _x Mn _1-x O ₂ (wherein 0.ltoreq.x.ltoreq.1), and Li _1+x MO ₂ (wherein M is one of Mn, ni, co and Al and 0.ltoreq.x.ltoreq.1). The spinel cathode comprises one or more ofA lithium-based positive electrode electroactive material selected from the group consisting of: liMn ₂ O ₄ (LMO) and LiNi _x Mn _1.5 O ₄ . Olivine-type cathodes comprising one or more lithium-based positive electroactive materials LiMPO ₄ (wherein M is at least one of Fe, ni, co and Mn). The polyanionic cation comprises, for example, a phosphate such as LiV ₂ (PO ₄ ) ₃ And/or silicate such as LiFeSiO ₄ 。

In one embodiment, one or more lithium-based positive electrode electroactive materials may optionally be coated (e.g., by LiNbO ₃ And/or Al ₂ O ₃ ) And/or may be doped (e.g., by magnesium (Mg)). Further, in certain embodiments, one or more lithium-based positive electrode active materials may optionally be mixed with one or more conductive materials that provide an electron conduction path and/or at least one polymeric binder material that improves the structural integrity of the positive electrode. For example, the positive electrode active material layer may include greater than or equal to about 30 wt% to less than or equal to about 98 wt% of one or more lithium-based positive electrode active materials; greater than or equal to about 0 wt% to less than or equal to about 30 wt% of a conductive material; and greater than or equal to about 0 wt% to less than or equal to about 20 wt% of a binder, and in certain aspects, optionally greater than or equal to about 1 wt% to less than or equal to about 20 wt% of a binder.

The positive electrode active material layer may be optionally mixed with a binder as follows: such as Polytetrafluoroethylene (PTFE), sodium carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVD F), nitrile rubber (NBR), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, lithium alginate, and combinations thereof. The conductive material may include carbon-based materials, powdered nickel or other metal particles, or conductive polymers. Carbon-based materials may include, for example, carbon black, graphite, acetylene black (e.g., KETCHENTM black or denktatm black), carbon fibers and particles of nanotubes, graphene, and the like. Examples of the conductive polymer include polyaniline, polythiophene, polyacetylene, polypyrrole, and the like.

As an embodiment, the positive electrode also contains a conductive agent, and the type of the conductive agent may be the same as that of the negative electrode, such as carbon-based materials, powdered nickel or other metallic particles or conductive polymers. The carbon-based material may include, for example, particles of carbon black, graphite, superP, acetylene black (such as KETCHENTM black or denktatm black), carbon fibers and nanotubes, graphene, and the like. Examples of the conductive polymer include polyaniline, polythiophene, polyacetylene, polypyrrole, poly (3, 4-ethylenedioxythiophene) polysulfstyrene, and the like.

The electrolyte may be a nonaqueous liquid electrolyte solution, which may include an organic solvent and a lithium salt dissolved in the organic solvent; on the other hand, in the other hand, the electrolyte may also be a solid electrolyte or a combination of both a nonaqueous liquid electrolyte solution and a solid electrolyte.

Lithium salts that are soluble in organic solvents generally have inert anions by way of illustrative example only and not by way of any limitation of the scope of protection, and may be used include: lithium hexafluorophosphate (LiPF) ₆ ) The method comprises the steps of carrying out a first treatment on the surface of the Lithium perchlorate (LiClO) ₄ ) Lithium tetrachloroaluminate (LiAlCl) ₄ ) Lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF) ₄ ) Lithium difluorooxalato borate (LiBF) ₂ (C ₂ O ₄ ) (LiODFB), lithium tetraphenylborate (LiB (C) ₆ H ₅ ) ₄ ) Lithium bis (oxalato) borate (LiB (C2O) ₄ ) ₂ ) Lithium tetrafluorooxalate phosphate (LiPF) ₄ (C ₂ O ₄ ) (LiFeP), lithium nitrate (LiNO) ₃ ) Lithium hexafluoroarsenate (LiAsF) ₆ ) Lithium triflate (LiCF) ₃ SO ₃ ) Lithium bis (trifluoromethanesulfonyl imide) (LITFSI) (LiN (CF) ₃ SO ₂ ) ₂ ) Lithium bis (fluorosulfonyl imide) (LiN (FSO) ₂ ) ₂ ) (LIFSI) and combinations thereof. In certain variations, the lithium salt is selected from lithium hexafluorophosphate (LiPF ₆ ) Lithium bis (trifluoromethanesulfonyl imide) (LiTFSI) (LiN (CF 3 SO) ₂ ) ₂ ) Lithium bis (fluorosulfonyl imide) (LiN (FSO) ₂ ) ₂ ) (LiFSI), lithium fluoroalkylphosphonate (LiFAP), lithium phosphate (Li) ₃ PO ₄ ) And combinations thereof.

As an embodiment, the present application is not particularly limited to an organic solvent that dissolves lithium salts, and any known organic solvent species can be used in the present application without departing from the inventive concept of the present application, including but not limited to various alkyl carbonates such as cyclic carbonates (e.g., ethylene Carbonate (EC), propylene Carbonate (PC), butylene Carbonate (BC), fluoroethylene carbonate (FEC)), linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC)), aliphatic carboxylic acid esters (e.g., methyl formate, methyl acetate, methyl propionate), gamma-lactones (e.g., gamma-butyrolactone, gamma-valerolactone), chain structure ethers (e.g., 1, 2-Dimethoxyethane (DME), 1-2-diethoxyethane, ethoxymethoxyethane), cyclic ethers (e.g., tetrahydrofuran, 2-methyltetrahydrofuran), 1, 3-Dioxolane (DOL), sulfur compounds (e.g., sulfolane), and combinations thereof. In a fully nonaqueous electrolyte system, the electrolyte may include one or more lithium salts at a concentration of greater than or equal to 1M to less than or equal to about 2M. In certain embodiments, for example when the electrolyte has a lithium concentration of greater than about 2M or has an ionic liquid, the electrolyte may include one or more diluents, such as fluorovinyl carbonate (FEC) and/or Hydrofluoroether (HFE).

When a nonaqueous liquid electrolyte system is used, further comprising separators disposed in the positive and negative electrodes, the separators may be microporous polymeric separators comprising polyolefins, including polyolefins made of homopolymers (derived from a single monomer component) or heteropolymers (derived from more than one monomer component), which may be linear or branched. In certain embodiments, the polyolefin may be Polyethylene (PE), polypropylene (PP), or a blend of PE and PP, or a multi-layer structured porous film of PE and/or PP.

When the separator is a microporous polymeric separator, it may be a single layer or a multi-layer laminate. For example, in one embodiment, a single layer of polyolefin may form the entire microporous polymer membrane. In certain embodiments, the separator may be a fibrous membrane having a plurality of pores extending between opposing surfaces and may have a thickness of less than 1 millimeter.

In addition to or in addition to polyolefin, the separator may include other polymers such as, but not limited to, polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), polyamide (nylon), polyurethane, polycarbonate, polyester, polyetheretherketone (PEEK), polyethersulfone (PES), polyimide (PI), polyamide-imide, polyether, polyoxymethylene (e.g., acetal), polybutylene terephthalate, polyethylene naphthenate (polyethylene naphthalate), polybutylene, polymethylpentene, polyolefin copolymers, acrylonitrile-butadiene-styrene copolymers (ABS), polystyrene copolymers, polymethyl methacrylate (PMMA), polysiloxane polymers (e.g., polydimethylsiloxane (PDMS)), polybenzimidazole (PBI), polybenzoxazole (PBO), polyphenylene (polyphenylene), polyarylene etherketone, polyvinylperfluorocyclobutane, polyvinylidene fluoride copolymers (e.g., PVdF-hexafluoropropylene or PVdF-HFP)) and polyvinyldifluoride terpolymers, polyvinylfluoride, liquid crystal polymers, polyaramides, mesoporous, fibrous materials, or combinations thereof.

In addition, the separator may be mixed with a ceramic material, or the surface thereof may be coated with a ceramic material. For example, the ceramic coating may include alumina (Al ₂ O ₃ ) Silicon dioxide (SiO) ₂ ) Or a combination thereof.

As an embodiment, the electrolyte may be a solid state electrolyte, and the solid state electrolyte particles may comprise one or more polymeric components, oxide solid state electrolytes, sulfide solid state electrolytes, halide solid state electrolytes, borate solid state electrolytes, nitride solid state electrolytes, or hydride solid state electrolytes. When polymer particles are used, lithium salts should be used for rechecking. As an embodiment, the polymer-based component may comprise one or more polymeric materials selected from the group consisting of: polyethylene glycol, polyethylene oxide (PEO), poly (p-phenylene oxide) (PPO), poly (methyl methacrylate) (PMMA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyvinylidene fluoride co-hexafluoropropylene (PVDF-HFP), polyvinyl chloride (PVC), and combinations thereof. It will be appreciated that the polymeric materialA high ionic conductivity is advantageous for the properties of the overall solid state electrolyte material, preferably the polymeric material should have a specific ionic conductivity of greater than or equal to 10 ^-4 S/cm ionic conductivity.

As an embodiment, the oxide particles may comprise one or more garnet ceramics, LISICON-type oxides, NASICON-type oxides, and perovskite-type ceramics. As an illustrative example, the garnet ceramic may be selected from the group consisting of: li (Li) _6.5 La ₃ Zr _1.75 Te _0.25 O ₁₂ 、Li ₇ La ₃ Zr ₂ O ₁₂ 、Li _6.2 Ga _0.3 La _2.95 Rb _0.05 Zr ₂ O ₁₂ 、Li _6.85 La _2.9 Ca _0.1 Zr _1.75 Nb _0.25 O ₁₂ 、Li _6.25 Al _0.25 La ₃ Zr ₂ O ₁₂ 、Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂ 、Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂ And combinations thereof. The LISICON-type oxide may be selected from the group consisting of: li (Li) ₁₄ Zn(GeO ₄ ) ₄ 、Li _3+x (P _1-x Si _x )O ₄ (wherein 0<x<1)、Li _3+x Ge _x V _1-x O ₄ (wherein 0<x<1) And combinations thereof. NASICON type oxide can be formed from LiMM' (PO ₄ ) ₃ And a definition wherein M and M' are independently selected from Al, ge, ti, sn, hf, zr and La. Preferably, the NASICON-type oxide may be selected from the group comprising: li (Li) _1+x Al _x Ge _2-x (PO ₄ ) ₃ (LAGP) (wherein 0.ltoreq.x.ltoreq.2), li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (LATP) (where 0.ltoreq.x.ltoreq.2), li _1+x Y _x Zr _2-x (PO ₄ ) ₃ (LYZP) (wherein 0.ltoreq.x.ltoreq.2), li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ 、LiTi ₂ (PO ₄ ) ₃ 、LiGeTi(PO ₄ ) ₃ 、LiGe ₂ (PO ₄ ) ₃ 、LiHf ₂ (PO ₄ ) ₃ And combinations thereof. The one or more perovskite ceramics may be selected from the group comprising: li (Li) _3.3 La _0.53 TiO ₃ 、LiSr _1.65 Zr _1.3 Ta _1.7 O ₉ 、Li _2x-y Sr _1-x Ta _y Zr _1-y O ₃ (wherein x=0.75 y and 0.60<y<0.75)、Li _3/8 Sr _7/16 Nb _3/ ₄ Zr _1/4 O ₃ 、Li _3x La _(2/3-x) TiO ₃ (wherein 0<x<0.25 A) and combinations thereof. Preferably, the one or more oxide-based materials can have an ionic conductivity of greater than or equal to about 10-5S/cm to less than or equal to about 10-1S/cm.

The sulfide solid state electrolyte is selected from one or more sulfide-based materials from the group consisting of: li (Li) ₂ S-P ₂ S ₅ 、Li ₂ S-P ₂ S ₅ -MS _x (wherein M is Si, ge and Sn and 0.ltoreq.x.ltoreq.2), li _3.4 Si _0.4 P _0.6 S ₄ 、Li ₁₀ GeP ₂ S _11.7 O _0.3 、Li _9.6 P ₃ S ₁₂ 、Li ₇ P ₃ S ₁₁ 、Li ₉ P ₃ S ₉ O ₃ 、Li _10.35 Si _1.35 P _1.65 S ₁₂ 、Li _9.81 Sn _0.81 P _2.19 S ₁₂ 、Li ₁₀ (Si _0.5 Ge _0.5 )P ₂ S ₁₂ 、Li(Ge _0.5 Sn _0.5 )P ₂ S ₁₂ 、Li(Si _0.5 Sn _0.5 )PsS ₁₂ 、Li ₁₀ GeP ₂ S ₁₂ (LGPS)、Li ₆ PS ₅ X (wherein X is Cl, br or I), li ₇ P ₂ S ₈ I、Li _10.35 Ge _1.35 P _1.65 S ₁₂ 、Li _3.25 Ge _0.25 P _0.75 S ₄ 、Li ₁₀ SnP ₂ S ₁₂ 、Li ₁₀ SiP ₂ S ₁₂ 、Li _9.54 Si _1.74 P _1.4 S _11.7 C _l0.3 、 _(1-x) P ₂ S _5-x Li ₂ S (wherein 0.5.ltoreq.x.ltoreq.0.7) and combinations thereof.

The halide solid state electrolyte may include one or more halide-based materials selected from the group consisting of: li (Li) ₂ CdC _l4 、Li ₂ MgC _l4 、Li ₂ Cd _I4 、Li ₂ ZnI ₄ 、Li ₃ OCl、LiI、Li ₅ ZnI ₄ 、Li ₃ OCl _1-x Br _x (wherein 0<x<1) And combinations thereof.

The borate solid state electrolyte is selected from one or more borate-based materials comprising the group of: li (Li) ₂ B ₄ O ₇ 、Li ₂ O-(B ₂ O ₃ )-(P ₂ O ₅ ) And combinations thereof.

The nitride solid state electrolyte may be selected from one or more nitride-based materials from the group consisting of: li (Li) ₃ N、Li ₇ PN ₄ 、LiSi ₂ N ₃ LiPON, and combinations thereof.

The hydride solid state electrolyte may be selected from one or more hydride-based materials from the group comprising: li (Li) ₃ AlH ₆ 、LiBH ₄ 、LiBH ₄ -LiX (wherein X is one of Cl, br and I), liNH ₂ 、Li ₂ NH、LiBH ₄ -LiNH ₂ And combinations thereof.

As a particular embodiment, the solid electrolyte may be a quasi-solid electrolyte comprising a mixture of the nonaqueous liquid electrolyte solution detailed above and a solid electrolyte system, e.g., comprising one or more ionic liquids and one or more metal oxide particles (such as alumina (Al ₂ O ₃ ) And/or silicon dioxide (SiO) ₂ ))。

The anode structure includes at least a current collector, an anode active material layer, and in some embodiments, a solid electrolyte layer and/or a lithium-compensating layer.

The specific materials of the current collector are not particularly limited in this application, and any known current collector material can be used in this application without departing from the inventive concept of this application, including but not limited to copper foil. In one embodiment, the current collector surface is coated with a conductive layer.

In one embodiment, the anode may include a lithium-based anode active material, which comprises, for example, lithium metal and/or a lithium alloy.

In one embodiment, the anode is a silicon-based anode active material comprising silicon, such as a silicon alloy and/or silicon oxide. In one embodiment, the silicon-based anode active material may also be mixed with graphite.

In one embodiment, the anode may include a carbonaceous-based anode active material including any one or a combination of at least two of graphite, graphene, or Carbon Nanotubes (CNTs).

In one embodiment, the anode includes one or more anode active materials that accept lithium, such as lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ ) Transition metals (e.g., sn), metal oxides (e.g., V) ₂ O ₅ ) Tin oxide (SnO), titanium dioxide (TiO) ₂ ) Titanium niobium oxide (TixNbyOz, where 0.ltoreq.x.ltoreq.2, 0.ltoreq.y.ltoreq. 24,0.ltoreq.z.ltoreq.64), metal alloys (e.g. copper-tin alloys (Cu) ₆ Sn ₅ ) Any one or a combination of at least two of metal sulfides such as iron sulfide (FeS).

In one embodiment, the anode active material in the anode may be doped with one or more conductive materials that provide an electron conduction path and/or at least one polymeric binder material that improves the structural integrity of the anode.

As an embodiment, the anode active material may be doped with a conductive material such as: any one or a combination of at least two of carbon-based materials, powdered nickel, other metal particles, or conductive polymers. Alternatively, the carbon-based material may include at least one particle such as carbon black, graphite, superP, acetylene black (e.g., KETCHENTM black or denktatm black), carbon fiber, carbon nanotubes, or graphene, among others. Alternatively, the conductive polymer may include at least one of polyaniline, polythiophene, polyacetylene, polypyrrole, poly (3, 4-ethylenedioxythiophene) polysulfstyrene, and the like.

As an embodiment, the anode active material may be doped with a binder such as: poly (tetrafluoroethylene) (PTFE), sodium carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile-butadiene rubber (NBR), styrene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, lithium alginate, and combinations thereof.

In one embodiment, the single cell extends along a first direction to form a tab, including a positive tab and a negative tab.

In another embodiment, the single cell extends along the second direction to form a tab, including a positive tab and a negative tab.

In one embodiment, the cells in the battery module are connected in series. At this time, the pole ear of each single electric core is opposite to the pole ear led out from the same side of the two adjacent electric cores, and when the pole ear of one single electric core on the side is an anode pole ear, the pole ears of the upper electric core and the lower electric core on the corresponding positions on the side are cathode pole ears, and the use of the collection wiring harness is further reduced through the welded connection of the pole ears, so that the residual space of the battery module except the electric cores is saved.

In one embodiment, the number of the battery cells stacked in the third direction in the battery module is L.ltoreq.30.

In one embodiment, the battery module further includes a buffer member 5 disposed between the unit cells to buffer the pressure received by the unit cells and absorb the expansion of the unit cells due to the increase of the charge and discharge times.

In one embodiment, the cushioning member 5 comprises a cushioning structure and adhesive layers disposed on both sides thereof.

In a preferred embodiment, the buffer 5 connects the cell closest to the housing in the third direction to the housing by gluing, connects the cell closest to the housing in the third direction to the housing cover, and fixes adjacent cells together. The single battery cells are horizontally stacked, the structure of the single battery cells has certain stability, and the single battery cells are fixed together through the buffer piece 5, so that the use of a supporting component, a fixing component and the like can be further saved, and the internal space of the battery is further saved.

In one embodiment, the cushioning member 5 is compressed foam.

In one embodiment, the battery module further includes: and the bracket 15 is further positioned on one side of the single battery cell leading-out tab. The total output tab passes through the bracket 15. Still further, the bracket 15 may be clamped to the edge of the plastic-aluminum film of the battery cell 11 to assist in fixing the battery cell 11.

To further reduce the weight of the battery module, the holder 15 may be made of plastic material.

As one embodiment, the length of the battery cell in the first direction is L ₁ Length in the third direction is L ₃ And L is ₁ And L ₃ The following relationship exists: l (L) ₁ /L ₃ And < 100. When the battery cells are too thin, deformation is easy to occur, and when too many battery cells are stacked in the same module in the third direction, the tab leading-out is increased, and the corresponding welding cost is increased.

In one embodiment, the battery module further includes: and an end cover 16, wherein the end cover 16 is welded with the tab. The end cover 16 and the bracket 15 are positioned on the same side, and the end cover 16 is made of plastic material.

In one embodiment, the battery module further comprises a housing, the battery module being carried within the housing; the casing includes the apron that is located electric core group 11 both sides along the third direction, including upper cover plate 12 and lower cover plate 13, electric core group 11 is along the outmost electric core of third direction and apron accessible bolster 5 carry out fixed connection. The cover plate comprises a main body part and an extension part extending along a third direction, the shell further comprises a side plate 14, the side plate 14 is arranged in parallel with the extension part of the cover plate, the cover plate wraps the side plate 14 through the extension part, and an end plate 17 is connected with the end cover 16 through clamping.

In one embodiment, the shells of the battery modules are fixed together in a welding mode, and the welding stationary phase is higher in bonding strength, better in tightness and lighter in mass compared with the modes of clamping, screwing and the like.

In one embodiment, the housing of the battery module includes an upper housing and a lower housing, and the upper and lower housings may be made of plastic material, so as to reduce the insulating coating layer on the outer side of the battery cell, and achieve the effect of light weight. Further, the upper casing and the lower casing are locked and fixed as a whole by bolts, and the bolts are provided in plurality along the peripheral side of the casing.

In one of in an embodiment of the present utility model, length L of battery module in third direction ₁₃ Satisfy L ₁₃ ≤100mm。

In a second aspect, the present application provides a battery pack including the battery module 1 as above, the battery pack being provided with at least one battery module 1 in a third direction.

In a preferred embodiment, the battery pack is provided with a battery module 1 in the third direction, so that the height of the battery pack in the third direction is further reduced, and the adaptability of the battery pack to a new energy automobile is improved.

In one embodiment, the battery pack further includes a liquid cooling structure 4, the liquid cooling structure 4 is disposed at the bottom of the battery pack, so that the internal space of the battery pack can be further saved, and the liquid cooling structure 4 is configured to dissipate heat of the battery module 1. Because the electric core is placed for the level in the battery module 1 in this application, the heat that its produced takes away, reduces battery temperature, avoids the emergence of excessive temperature rise.

In an embodiment, the battery pack further comprises a tray 2 and an upper cover 3, the tray 2 is used for bearing the battery core, the interior of the tray 2 is divided into a plurality of areas, the plurality of areas are respectively used for placing the battery module 1 and various facilities matched with the battery module 1, such as a high-low pressure plug-in unit, an explosion-proof valve, a BDU, a BMS3 and the like, the plurality of battery modules 1 and the high-low pressure plug-in units, the explosion-proof valve, the BDU, the BMS and other parts are installed in the tray 2, and the upper cover 3 is fixed after the assembly is completed.

The following is a description of embodiments of the present application, with specific data presented in table 1, taking the assembly of a battery pack with a power bench providing 350V as an example.

Example 1

In this embodiment, the battery module 1 includes 1 battery cell group 11, the battery cell group 11 is formed by stacking 16 soft package battery cells along a third direction, and through series connection, the size of the soft package battery cells is 640mm x 600mm x 4mm, along the third direction, the battery pack includes one battery module 1, and the total number of the battery modules 1 in the battery pack is 6.

Implementation of the embodiments example 2

The difference between this embodiment and embodiment 1 is that the cell group 11 includes 12 soft package cells, and the cell size is 50mm by 530mm by 6mm; the total number of battery modules 1 in the battery pack is 8.

For a pair of proportion 1

In this comparative example, in the battery module 1, the width direction of the battery cells is used as the vertical direction to be stacked, the number of the soft package battery cells is 16, the size of a single soft package battery cell is 640mm by 120mm by 10mm, the number of the battery modules 1 is 1 along the third direction, and the total number of the battery modules 1 is 6.

TABLE 1

From table 1, it can be seen that the stacking manner of horizontally placing the battery cells can effectively reduce the height of the battery pack and improve the adaptability of the battery pack to new energy automobiles.

It is apparent that the above examples of the present application are merely illustrative examples of the present application and are not limiting of the embodiments of the present application. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the application. It is not necessary here nor is it exhaustive of all embodiments. Any modifications, equivalent substitutions, improvements, etc. that fall within the spirit and principles of the present application are intended to be included within the scope of the claims of this application.

Claims

1. A battery module, characterized in that the battery module is arranged in a flat shape;

the battery module comprises a plurality of battery cells, and the battery cells are stacked together in a horizontal placement mode to form a battery cell group (11);

the length of the battery cell in the first direction is L ₁ Length in the second direction is L ₂ L is then ₁ And L ₂ The following relationship exists: l is more than or equal to 1.01 ₁ /L ₂ ≤2。

2. The battery module of claim 1, wherein the cells have a length L in a first direction ₁ Length in the third direction is L ₃ And L is ₁ And L ₃ The following relationship exists: l (L) ₁ /L ₃ ＞20。

3. The battery module according to claim 1, wherein the battery cell is a soft package battery cell, and comprises a bare cell and an aluminum plastic film arranged outside the bare cell;

the cells are connected together in series.

4. A battery module according to any one of claims 1-3, characterized in that the battery module further comprises a buffer member (5), the buffer member (5) comprises a buffer structure and adhesive layers arranged on both sides thereof, and the adhesive layers are used for fixedly connecting adjacent cells, and the cells and the case cover (3).

5. The battery module according to claim 1, wherein, length L of the battery module in the third direction ₁₃ The method meets the following conditions: l (L) ₁₃ ≤100mm。

6. The battery module according to claim 1, further comprising a bracket (15);

the battery module further comprises a housing (2).

7. Battery pack, characterized in that it comprises a battery module (1) according to claim 1, at least one of said battery modules (1) being arranged in a third direction.

8. The battery pack according to claim 7, further comprising a liquid cooling structure (4), wherein the liquid cooling structure (4) is disposed at a bottom position of the battery pack.