WO2018080183A1

WO2018080183A1 - Battery system and electric vehicle comprising same

Info

Publication number: WO2018080183A1
Application number: PCT/KR2017/011885
Authority: WO
Inventors: 고루브코브안드레
Original assignee: 삼성에스디아이 주식회사
Priority date: 2016-10-26
Filing date: 2017-10-26
Publication date: 2018-05-03

Abstract

The present invention relates to a battery system and an electric vehicle comprising the same, the battery system comprising a plurality of battery cells arranged so as to be spaced apart from each other in a first direction and respectively arranged in a second reaction, wherein each of the plurality of battery cells comprises: a plurality of battery modules including an electrode assembly and accommodated in a battery case having the bottom surface; and a base plate supporting the battery modules and including a first main surface making thermal contact with the bottom surface of the battery case, and a heat conductivity according to a first direction of the base plate is greater than a heat conductivity according to a second direction of the base plate.

Description

Battery system and electric vehicle including same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery system and an electric vehicle, and relates to a battery system including a base plate provided to prevent thermal runaway spreading and an electric vehicle including the same.

Rechargeable or secondary batteries differ from primary batteries in that charging and discharging can be repeated, and primary batteries provide only an irreversible conversion of chemicals into electrical energy.

Low-capacity rechargeable batteries are used as power sources for small electrical devices such as mobile phones, laptops, computers and camcorders, while large-capacity rechargeable batteries are used as power sources for hybrid vehicles.

In general, the secondary battery includes an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, a case accommodating the electrode assembly, and an electrode terminal electrically connected to the electrode assembly.

The electrolyte is injected into the case to enable the charging and discharging of the battery through the electrochemical reaction of the positive electrode, the negative electrode, and the electrolyte. The shape of the case is, for example, cylindrical or rectangular, depending on the use of the battery.

The rechargeable battery may be used in the form of a battery module formed of a plurality of unit battery cells coupled in series and / or in parallel to provide a high energy density, for example, for driving a motor of a hybrid vehicle.

That is, the battery module is formed by interconnecting the electrode terminals of the plurality of unit battery cells according to the amount of power required to implement a high power rechargeable battery for an electric vehicle, for example.

The battery module may be designed in a block or modular form. In the case of the block type, each battery is coupled to a common current collector and a common battery management system, and the cells can be disposed in the common housing.

In the case of the modular type, a plurality of battery cells are connected to form a sub module, and some sub modules are connected to form a battery module. The battery management function may be implemented at least partially at the battery module or submodule level, thereby improving compatibility.

One or more battery modules are mechanically and electrically integrated, have a thermal management system, and are connected with one or more electrical consumer devices to constitute the battery system.

Mechanical integration of the battery system requires proper mechanical connection between individual components, such as for example submodules, and proper mechanical connection with system structures that provide electrical consumption devices, such as, for example, automobiles.

These connections should be designed to maintain functionality for the life of the battery system and to take into account the load provided during consumer use.

In addition, for mobile devices, requirements for footprint and compatibility must be met.

Mechanical integration of the battery module may be accomplished by providing a base plate and placing each battery cell or submodule thereon.

Fixing the battery cell or submodule may be accomplished by an indentation installed in the carrier plate, by a mechanical connection element such as a bolt or screw, or by the restraint of the cell or submodule.

The restraint can be accomplished by securing the sideplates to the sides of the carrierplate or by providing another carrierplate on the top side and fixing them to the existing first carrierplate and / or sideplates.

Accordingly, a multilevel battery module may be constructed in which the carrier plate and / or the side plate include a refrigerant duct for cooling the cell or submodule.

Mechanical integration of the submodule can be achieved by providing a mechanically strengthened electrical connection member or by fixing the battery cell to a carrier beam or strut in addition to the electrical connection member.

Additionally / optionally, the submodule may be arranged in each casing covering part or all of the surface of the battery submodule, for example together with the casing in the battery module on the carrier plate.

In the design of the module, for the electrical integration of the battery system, submodules having a plurality of cells connected in parallel are connected in series (XsYp), or submodules having a plurality of cells connected in series are connected in parallel (XpYs).

XpYs type submodules can generate high voltages, but the wiring complexity increases because the voltage levels of each cell must be controlled individually. In the XsYp type submodule, the voltage levels of cells connected in parallel are automatically balanced.

Therefore, it is sufficient to control the voltage at the submodule level, and the wiring complexity is reduced. In the submodules of cells connected in parallel, the capacities of the cells are combined, so the XsYp type submodule is mostly used for low capacity cells.

It is not enough to statically control battery output and charging to meet the dynamic power demands of various electrical consumers connected to the battery system. Therefore, a continuous exchange of information must be made between the battery system and the controller of the electric consumer device.

This information includes the actual SoC, potential electrical performance, charge capacity and internal resistance of the battery system, as well as the actual or expected power demand or remaining power of the consumer.

The battery system typically includes a battery management system for processing this information.

For thermal control of battery systems, there is a need for a thermal management system to safely use at least one battery module by efficiently discharging, dissipating and / or dissipating heat generated from rechargeable batteries.

If heat dissipation / discharge / dispersion is not sufficiently performed, a temperature deviation occurs between each battery cell, so that at least one battery module cannot generate the required amount of power.

In addition, an increase in the internal temperature can cause abnormal reaction therein, so that the charge and discharge performance of the rechargeable battery can be degraded and its life can be shortened.

Therefore, there is a need for a cooling device that efficiently discharges / discharges / disperses heat from the cell.

An example of such abnormal operating conditions is the thermal runaway of a battery cell, which can be caused by a severely overheated or overcharged lithium ion cell.

The critical temperature for thermal runaway is generally above 150 ° C. and may exceed the critical temperature due to local failure, internal short circuit of the cell, heat generation by poor electrical contact or short circuit of adjacent cells.

Thermal runaway is a chemical process that self-accelerates inside the cell until all active material is consumed, during which fault cells can be heated to cell temperatures above 700 ° C and large amounts of hot gas can be released into the system.

Fault cells can transfer large amounts of heat to adjacent cells during thermal runaway. The adjacent cells are in direct contact with the faulty cell, heat conduction through the baseplate and / or heat transfer through their electrical connection members.

Thus, adjacent cells are also susceptible to thermal runaway, and thermal runaway spread can eventually lead to battery fire and / or total loss of the electric vehicle throughout the battery module.

On the other hand, the battery system may include a base plate provided with active cooling means for heat dissipation. However, such active cooling means are typically provided to provide uniform cooling to the attached battery cells.

Accordingly, the risk of heat diffusion and the occurrence of a plurality of faulty cells due to the temperature gradient by the faulty cells continues.

It is therefore an object of the present invention to provide a battery system having improved battery cell cooling to overcome or reduce at least some of the drawbacks of the prior art and to prevent unintended heat spreading and thermal failure.

The matters described as the background art are only for the purpose of improving the understanding of the background of the present invention, and should not be taken as acknowledging that they correspond to the related art already known to those skilled in the art.

Embodiments of the present invention are to provide a battery system including a base plate having anisotropic thermal conductivity to prevent thermal runaway spreading and an electric vehicle including such a battery system.

According to an embodiment of the present invention, a battery system including a plurality of battery modules and a base plate is provided.

The battery modules may be spaced apart from each other in a first direction, and each battery module may include a plurality of battery cells arranged and aligned in a second direction.

The first and second directions may be substantially perpendicular to each other and may form an angle of approximately 90 °.

Each battery cell includes an electrode assembly accommodated in a battery case, each battery case may include a bottom surface.

The base plate may support the battery module and include a first main surface in thermal contact with a bottom surface of each of the plurality of battery cases.

The baseplate may basically have a flat shape and / or at least one face extending between the first and second directions. The level of extension in the third plate in the third direction is considerably smaller than the first and second directions, and the third direction may be substantially perpendicular to the first and second directions.

The thermal conductivity (thermal conductivity) of the base plate in the first direction may be greater than the thermal conductivity of the base plate in the second direction.

Therefore, in the battery system according to the present invention, the heat discharged by the battery cells is more effectively transferred in the first direction than in the second direction.

Therefore, heat is moved away from the immediately neighboring cell in the same module as the heat dissipation cell and transferred to the cells of the adjacent battery module.

Thus, the thermal conduction of the baseplate induces one-way heat diffusion across the entire cell system.

As a result, the total increase in heat can be reduced in each battery cell, particularly in the battery cell of the same module as the fault cell and in a cell adjacent to the fault cell, thereby reducing the risk of thermal runaway spreading.

In one embodiment of the battery system according to the present invention, the base plate may include a first material having a first thermal conductivity.

The base plate may further include a plurality of insulating parts extending in the first direction and having a second thermal conductivity lower than the first thermal conductivity.

The insulating part may be installed or integrally provided on the base plate, and may be disposed to penetrate the first main surface of the base plate or to be close to the first main surface of the base plate.

The insulating part may be in thermal contact with the first main surface or may be embedded, interposed, or attached to the first main surface.

The insulation parts may be spaced apart in the second direction and parallel to each other.

The insulation unit may periodically block heat conduction in the second direction through the base plate to effectively lower the coefficient component associated with at least the second direction of the heat transfer coefficient of the base plate.

The baseplate may consist of a first material, for example aluminum or a thermally conductive polymer, or a first mixture, for example a metal alloy or a polymer mixture.

The insulation may comprise a second material having a second thermal conductivity, such as a metal, polymer or ceramic having a low thermal conductivity.

Additionally or alternatively, the insulation can achieve low thermal conductivity through structural features such as multiple voids or cavities.

The battery case may be a rectangular battery case, a cylindrical battery case or a flexible battery pouch, as long as the bottom surface is in thermal contact with the base plate.

Each battery case includes a pair of first side walls vertically connected to both ends of the first wide side and the second wide side, that is, the bottom side, and aligned in a first direction.

Preferably, the first wide side faces the second wide side and the bottom is basically rectangular in shape.

The battery case may further include a pair of second side walls which are vertically connected to both opposite ends of the bottom surface and face each other and perpendicular to the pair of first side walls.

The bottom surface, the pair of first side walls and the pair of second side walls may form a volume for the electrode assembly.

The cap assembly including the terminals of the battery cell is disposed opposite the bottom surface to close the case. In other words, the battery cell may be a rectangular battery cell contained in a packaging can.

Each battery module includes a plurality of rectangular battery cells stacked in a second direction so that the second wide side surface of the first battery cell faces the first wide side surface of the adjacent second battery cell in the same module.

The stacked battery cells do not directly contact each other, but in the same module, a gap (spaced space) is formed in a first direction between the second wide side wall of the first battery cell and the first wide side wall of the second battery cell adjacent to the first battery cell. It is extended.

The gap may be void, filled with adiabatic spacers, and used for active cooling of the sides of adjacent cells.

Each of the insulation parts is aligned with any one of the plurality of gaps along the first direction. That is, the insulating unit is disposed between adjacent cells in the same battery module.

When the battery modules are aligned, the insulation may extend along the gap in the plurality of battery modules.

Since the wide sides of adjacent battery cells are not in direct contact, heat transfer between these cells occurs mainly by heat conduction through the baseplate.

By placing the insulation in the baseplate and aligning the gaps between the cells, the heat transfer path between adjacent cells is blocked.

The insulation may extend continuously in the first direction across approximately the entire length of the baseplate.

The insulating portion extends over the entire length of the active region of the base plate, and the battery module may be disposed in the active region of the base plate.

Continuous insulation interferes with heat conduction in the second direction over the entire length of the baseplate in the first direction.

In addition, the base plate in which the insulation portion extends continuously can be easily manufactured.

However, according to another embodiment, the insulation portion extends over the entire length of the base plate along the first direction as a broken line, the gap of the insulation portion formed in the broken line may be disposed between adjacent battery modules.

In this embodiment, the thermal conductivity in the second direction of the base plate can also be sufficiently reduced as the mechanical stability of the base plate is increased than the above-described embodiment.

The insulating portion extends from the first main surface of the base plate to the second main surface of the base plate opposite to the first main surface. That is, the insulating part may completely penetrate the base plate from the first main surface to the second main surface.

That is, for example, in the cross section along the second direction in the base plate portion having the first thermal conductivity by the first material, for example, the portion having the second thermal conductivity by the second material path follows, and vice versa. .

The base plate may include, for example, cutting a plurality of concave grooves extending in the first direction from the first main surface of the base plate, filling the concave grooves with a material having a lower thermal conductivity compared to the base plate, and It can be produced by introducing a step (for example, grinding of the second main surface) by scraping the base plate in the second main surface until the second main surface opposite to the one main surface touches the filled concave groove.

Alternatively, for example, a plurality of insulating parts made of a heat insulating and high temperature resistant polymer may be put into a mold, for example, made of aluminum, and may be firmly combined with a base plate cast from the mold.

Since the base plate according to this embodiment does not have a bypass path through which heat is conducted around the insulation, the base plate greatly reduces the second direction heat conduction of the base plate.

According to another embodiment of the present invention, the insulating portion may be a recessed groove embedded in the first main surface of the base plate.

That is, the insulating portion extends from the first main surface of the base plate toward the second main surface opposite to the first main surface, but does not completely penetrate the base plate.

The base plate according to this embodiment can be manufactured by cutting the concave groove as described above, the step of cutting the base plate in the second main surface of the base plate is omitted.

At the beginning of the manufacturing process, the base plate including the concave groove is cast in a mold corresponding thereto, thereby reducing the material cost. According to this embodiment, the recess is filled with a material having a second thermal conductivity which remains cavities or is lower than the first thermal conductivity.

The recess can be filled with a heat insulating polymer. According to this embodiment, a base plate having mechanically stable anisotropy thermal conductivity can be easily manufactured.

The battery system according to the present invention may include a plurality of heat radiating parts extending in the first direction. The heat dissipation parts may be spaced apart from each other and parallel to each other in the second direction. The baseplate may additionally or alternatively comprise the heat dissipation portion with respect to the insulation portion.

The heat dissipating part and the insulating part may be alternate with each other along the second direction of the base plate. Each heat dissipation portion is aligned with respect to at least one battery case bottom, and preferably with respect to the plurality of battery case bottoms.

That is, each heat dissipation portion is in thermal contact with at least one or preferably more battery case bottoms. The heat dissipation unit is provided to increase the thermal conductivity of the base plate in the first direction. Thus, an anisotropic (anisotropic) thermal conductivity of an excellent and advantageous base plate can be realized or improved.

Heat discharged from the faulty cell is transferred away from neighboring cells in the same module by being transferred to an adjacent module along the first direction.

The heat dissipation part may include a third material having a third thermal conductivity higher than the first thermal conductivity, which is the thermal conductivity of the base plate, and / or the second thermal conductivity, which is the thermal conductivity of the insulating part.

The heat dissipation unit may be a cooling channel provided integrally with the base plate and provided to guide the refrigerant. The cooling channel is provided to increase the thermal conductivity and / or heat dissipation of the baseplate in the first direction while at least filled with the refrigerant.

The heat dissipation portion, for example the cooling channel, preferably extends continuously across the entire length of the base plate in the first direction. Preferably, the cooling channel may further include a refrigerant port provided so that the end portion is attached to the outside of the cooling circuit.

The cooling channel itself may be formed of a third material having a third thermal conductivity higher than the first thermal conductivity and / or the second thermal conductivity. The third material may be copper.

As aqueous or oily refrigerant flows through the cooling channel, heat dissipation as well as thermal conductivity in the first direction of the base plate increases.

Meanwhile, another embodiment of the present invention relates to a base plate for a battery system, that is, a base plate provided to support a plurality of battery modules, wherein the base plate extends to at least one surface between a first direction and a second direction. And the thermal conductivity of the base plate in the first direction is greater than the thermal conductivity in the second direction.

The thickness of the base plate in the third direction perpendicular to the first direction and the second direction may be smaller than the extended length of the first direction and the second direction of the base plate.

The base plate for the battery system is provided to support a plurality of battery modules arranged spaced apart from each other in the first direction, the battery module includes a plurality of battery cells arranged and aligned in the second direction, each battery cell has a bottom surface The branch includes an electrode assembly housed in a battery case.

Therefore, the base plate according to the present invention effectively transfers the heat discharged from the battery cell in the first direction rather than the second direction. Therefore, heat is transferred to the cells of adjacent modules instead of directly to neighboring cells of the heat dissipating cells.

Anisotropic heat conduction in the baseplate induces more unidirectional heat diffusion between the battery cells supported by the baseplate.

Therefore, the baseplate can reduce the maximum increase in heat in each battery cell, and can reduce the risk of thermal runaway diffusion.

The base plate may include a first material having a first thermal conductivity.

The base plate may be made of a first material or a first mixed material having a first thermal conductivity.

The insulating part may be integrally provided or attached to the base plate, and may be disposed to penetrate the first main surface of the base plate or to be close to the first main surface in the base plate.

The insulating portion may be in thermal contact with the first main surface and may be embedded or attached to the first main surface.

The plurality of insulation parts may be spaced apart from each other in a second direction and provided in parallel with each other.

The insulating section periodically interrupts the heat conduction of the base plate in the second direction to effectively lower the components of the heat transfer coefficient of the base plate, at least in relation to the second direction.

The baseplate consists of a first material, for example aluminum or a thermal conductivity polymer, or a first mixture, for example a metal alloy or a polymer mixture. The insulation preferably comprises a second material having a second thermal conductivity, such as a metal, polymer or ceramic having a low thermal conductivity.

The insulation may extend continuously in the first direction across substantially the entire length of the baseplate.

However, according to another embodiment, the insulating portion may extend over the entire length of the base plate along the first direction as a broken line.

For example, in the cross section taken along the second direction from the base plate portion having the first thermal conductivity by the first material, for example, the portion having the second thermal conductivity by the second material follows, and vice versa. .

The base plate may include, for example, cutting a plurality of concave grooves extending in the first direction from the first main surface of the base plate, filling the concave grooves with a material having a lower thermal conductivity compared to the base plate, and It can be produced by introducing the step of scraping the base plate in the second main surface until the second main surface opposite to the one main surface touches the filled concave groove.

Alternatively, for example, a plurality of insulating parts made of a heat insulating and high temperature resistant polymer may be put into a mold, and may be firmly coupled to a base plate made of, for example, aluminum and cast from the mold.

In the base plate according to this embodiment, since there is no bypass path for conducting heat around the insulating part, the second plate may significantly reduce the heat conduction of the base plate in the insulating part.

According to another embodiment of the present invention, the insulating portion may be a concave groove interposed or embedded in the first main surface of the base plate. In other words, the insulation does not penetrate the entire thickness of the base plate.

The base plate according to this embodiment can be manufactured by cutting the concave groove as described above, and the step of cutting (grinding) the base plate in the second main surface of the base plate is omitted.

At the beginning of the manufacturing process, the base plate including the concave groove is cast in a mold corresponding thereto, thereby reducing the material cost.

According to this embodiment, the recess is filled with a material having a second thermal conductivity which remains cavities or is lower than the first thermal conductivity.

The battery system according to the present invention may include a plurality of heat radiating parts extending in the first direction.

The heat dissipation parts may be spaced apart from each other and parallel to each other in the second direction. The baseplate may additionally or alternatively comprise the heat dissipation portion with respect to the insulation portion. The heat dissipation unit and the insulation unit may be alternately arranged along the second direction of the base plate.

The base plate may be provided such that the battery cell is supported on the upper side of the heat dissipation part so that the bottom surface of the battery cell is in thermal contact with the heat dissipation part.

The heat dissipation unit is provided to increase the thermal conductivity of the base plate in the first direction.

The heat dissipation unit may be a cooling channel provided integrally with the base plate and provided to guide the refrigerant.

The cooling channel is arranged to increase the thermal conductivity and / or heat dissipation (heat dissipation) of the baseplate in the first direction while at least filled with the refrigerant.

The heat dissipation portion, eg the cooling channel, preferably extends continuously across the entire length of the base plate in the first direction.

The cooling channel may further include a refrigerant port provided at the distal end to be attached to the outside of the cooling circuit.

The cooling channel may be formed of a third material having a third thermal conductivity higher than the first thermal conductivity and / or the second thermal conductivity. The third material may be copper.

As the aqueous or oily refrigerant flows through the copper cooling channel, the heat dissipation amount as well as the thermal conductivity in the first direction of the base plate is increased as compared to the second direction.

Another aspect of the invention relates to an electric vehicle comprising a battery system as described above and / or comprising a base plate as described above.

Further aspects of the invention will be apparent from the claims, the drawings and the following description.

Embodiments of the present invention allow the thermal conductivity of the base plate in the first direction to be greater than the thermal conductivity of the base plate in the second direction, inducing unidirectional heat diffusion across the battery system, thereby reducing the risk of thermal runaway propagation. It is possible to provide a battery system and an electric vehicle including the same.

1 is a perspective view of a battery cell according to an embodiment of the present invention.

2 is a cross-sectional view of a battery cell according to an embodiment of the present invention.

3 is a side view schematically showing a conventional battery system.

4 is a side view schematically showing a battery system according to a first embodiment of the present invention.

5 is a plan view schematically illustrating a battery system and a base plate according to a first embodiment of the present invention.

6 is a plan view schematically illustrating a battery system and a base plate according to a second embodiment of the present invention.

7 is a side view schematically showing a battery system according to a third embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In this specification, duplicate descriptions of the same components are omitted.

Also, in the present specification, when a component is referred to as being 'connected' or 'connected' to another component, the component may be directly connected to or connected to the other component, but in between It will be understood that may exist. On the other hand, in the present specification, when a component is referred to as 'directly connected' or 'directly connected' to another component, it should be understood that there is no other component in between.

Also, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Also, in this specification, the singular forms may include the plural forms unless the context clearly indicates otherwise.

Also, as used herein, the term 'comprises' or 'having' is only intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more. It is to be understood that it does not exclude in advance the possibility of the presence or addition of other features, numbers, steps, actions, components, parts or combinations thereof.

Also in this specification, the term 'and / or' includes any combination of the plurality of listed items or any of the plurality of listed items. In the present specification, 'A or B' may include 'A', 'B', or 'both A and B'.

1 is a perspective view of a battery cell according to an embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line IV-IV of FIG.

As shown in FIG. 1 and FIG. 2, the battery cell 80 according to the exemplary embodiment of the present invention includes an electrode assembly 10 and a case 26 containing the electrode assembly 10 and the electrode assembly 10. do.

The battery cell 80 may also include a cap assembly 30 for sealing the opening of the case 26. The battery cell 80 will be described as an example that is not limited to a lithium ion secondary battery.

The electrode assembly 10 may be formed of a jelly roll type electrode assembly in which the anode 11 and the cathode 12 are spirally wound with the separator 13 interposed therebetween.

The positive electrode 11 and the negative electrode 12 may each include a coating area of a current collector formed of a thin metal foil coated with an active material, and the positive and negative electrode

uncoated portions

11a and 12a of the current collector not coated with the active material. Each may include.

As an example, the coating area of the anode 11 may be formed by coating an active material such as a transition metal oxide on a substrate formed of a metal foil such as aluminum foil.

In addition, the coating area of the cathode 12 may be formed by coating an active material such as carbon, graphite, or the like on a substrate formed of a metal foil such as copper or nickel foil.

The positive electrode non-coating region 11a may be formed at one end in the longitudinal direction of the positive electrode 11, and the negative electrode non-coating region 12a may be formed at one end in the longitudinal direction of the negative electrode 12.

The positive electrode non-coating portion 11a and the negative electrode non-coating portion 12a may be opposite sides with respect to the coating area.

In addition, the separator 13 may include a plurality of separators that can be wound in a spiral after the anode 11, the cathode 12, and the separator 13 are alternately positioned.

However, the present invention is not limited thereto, and the electrode assembly 10 may have a structure including a plurality of anodes 11, separators 13, and cathodes 12 repeatedly stacked in a sheet shape.

The electrode assembly 10 may be accommodated in the case 26 together with the electrolyte. The electrolyte may be composed of an organic solvent such as EC, PC, DEC, EMC, and a lithium salt such as LiPF 6 or LiBF 4. The electrolyte can be in liquid, solid or gel state.

The case 26 may be configured in a substantially rectangular parallelepiped shape, and an opening may be formed in one surface thereof. The case 26 may be formed of a metal such as aluminum.

The case 26 may include a substantially rectangular bottom surface 27, and may include a pair of first side walls corresponding to the wide side surfaces 18 and 19 to form a space for accommodating the electrode assembly 10. Each may include a pair of second sidewalls connected perpendicularly to an end of the bottom surface.

The

first side walls

18 and 19 may be provided to face each other, and the second side walls may be arranged to face each other and may be connected to the

first side walls

18 and 19.

The length of the edge at which the bottom surface 27 and the

first side walls

18 and 19 are connected to each other may be longer than the length of the edge at which the bottom surface 27 and the second side walls are connected to each other. Preferably, the adjacent first and second side walls are at an angle of approximately 90 °.

The cap assembly 30 may include a cap plate 31 coupled to the case 26 to cover the opening of the case 26, and the cap assembly 30 may be electrically connected to the negative electrode 11 and the positive electrode 12, respectively. It may include a positive terminal (first terminal) 21 and a negative terminal (second terminal) 22 protruding outward from the plate 31.

Cap plate 31 may be provided in the form of a plate extending in one direction, it may be coupled to the opening of the case 26. The cap plate 31 may include an injection hole 32 and a vent hole 34 communicating with an inside of the cap assembly 30.

The inlet 32 can be configured to allow the injection of electrolyte, and a sealing cap 38 can be mounted thereon or in it. In addition, the vent member 39 may be opened at a set pressure and provided on the vent hole 34, and may include a notch 39a to facilitate the opening thereof.

The positive electrode terminal 21 and the negative electrode terminal 22 may be mounted to protrude upward from the cap plate 31.

The positive electrode terminal 21 may be electrically connected to the positive electrode 11 through the current collector tab 41, and the negative electrode terminal 22 may be electrically connected to the negative electrode 12 through the current collector tab 42. A terminal connecting member 25 for electrically connecting the positive electrode terminal 21 and the current collecting tab 41 may be mounted between the positive electrode terminal 21 and the current collecting tab 41.

The terminal connection member 25 may be inserted into a hole formed in the positive electrode terminal 21 so that the lower portion thereof may be welded to the current collector tab 41. The sealing gasket 59 may be inserted between the terminal connecting member 25 and the cap plate 31 through a hole in which the terminal connecting member 25 extends.

In addition, a lower insulating member 43 into which the lower portion of the terminal connection member 25 may be inserted may be mounted to the lower portion of the cap plate 31. A connecting plate 58 for electrically connecting the positive electrode terminal 21 and the cap plate 31 may be mounted between the positive electrode terminal 21 and the cap plate 31.

The terminal connecting member 25 may be inserted into the connecting plate 58. Therefore, the cap plate 31 and the case 26 can be charged with the positive electrode.

Similar to the terminal connecting member 25 described above, a terminal connecting member 25 for electrically connecting the negative electrode terminal 22 and the current collecting tab 42 is installed between the negative electrode terminal 22 and the current collecting tab 42. Can be.

The terminal connection member 25 may be inserted into a hole formed in the negative electrode terminal 22 so that the upper and lower portions of the terminal connection member 25 may be welded to the negative electrode terminal 22 and the current collector tab 42, respectively.

Similar to the gasket 59 described above, a sealing gasket may be inserted between the negative electrode terminal 22 and the cap plate 31 through a hole through which the terminal connecting member 25 may extend.

In addition, a lower insulating member 45 for insulating the negative electrode terminal 22 and the current collector tab 42 from the cap plate 31 may be mounted below the cap plate 31.

An upper insulating member 54 for electrically insulating the negative electrode terminal 22 and the cap plate 31 may be mounted between the negative electrode terminal 22 and the cap plate 31. The terminal connecting member 25 may be inserted into a hole formed in the upper insulating member 54.

The cap assembly 30 may include a shorting hole 37 and a shorting member 56 installed in the shorting hole 37 and shorting the positive electrode 11 and the negative electrode 12.

The short circuit member 56 may be provided between the upper insulation member 54 and the cap plate 31, and the upper insulation member 54 may be configured to have a cutout portion that may be formed at a position corresponding to the short circuit member 56. Can be.

The short circuit member 56 may overlap the negative electrode terminal 22 exposed through the cutout and may be positioned to be separated.

In addition, the short circuit member 56 may be between the negative electrode terminal 22 and the vent hole 34, and may be located closer to the negative electrode terminal 22 than the vent hole 34.

The short circuit member 56 may include a convex curved portion curved toward the electrode assembly 10, and may include an edge portion that may be formed outside the curved portion and fixed to the cap plate 31. .

When the internal pressure of the battery cell 80 increases, the short circuit member 56 may be deformed to cause a short circuit.

In other words, when gas is generated by an unintended reaction in the battery cell 80, the internal pressure of the battery cell 80 may increase.

When the internal pressure of the battery cell 80 rises above a certain level (for example, a set level), the bent portion may be deformed to be curved concave in the opposite direction, whereby the shorting member 56 is connected to the negative electrode terminal 22. A short circuit occurs in contact.

3 shows a schematic side view of a battery system 100 according to the prior art. Here, the battery module 90 including the plurality of stacked battery cells 80 is disposed above the base plate 60.

Each battery cell 80 is a rectangular battery cell 80 as described above, and includes a battery case 26. The case 26 includes a bottom surface 27 opposite the cap assembly including the terminal 21, which bottom surface 27 is in thermal contact with the base plate 60.

The cells 80 have a gap 28 between the

adjacent battery cells

81, 82, with the second wide side 19 of the first battery cell facing the first wide side 18 of the second battery cell 82. It is laminated so that it is formed. The base plate 60 is a flat plate formed of a single body by a single material.

4 and 5 show schematic side and top views of (A) battery system 100 and (B) baseplate 60 according to the first embodiment of the invention.

The battery system 100 according to the first embodiment includes a plurality of battery modules 90 spaced apart in the first direction y. Each battery module 90 includes a plurality of rectangular battery cells 80 as described above stacked or arranged in a second direction (x).

Each battery cell 80 includes a battery case 26 and a cap assembly 30, and the cap assembly includes positive and

negative terminals

21 and 22, for example.

Each battery case 26 includes a bottom surface 27 and a pair of

first side walls

18 and 19. The cells are positioned on the base plate 60 so that the bottom surface 27 of each battery case 26 is in thermal contact with the first main surface 61 of the base plate 60.

The

first side walls

18, 19 or wide side surfaces extend along the first direction and are aligned to face the first direction. In other words, the first side wall is aligned with the first direction.

In any one of the battery modules 90, the plurality of cells 80 may face the first wide side surface 18 of the second battery cell 82 so that the second wide side surface 19 of the first battery cell 81 faces each other. It is arranged in the second direction x. That is, a gap 28 between cells 80 is formed between the opposing

wide sides

18, 19 of two neighboring cells 80. In addition, the gap 28 is formed such that its extended longitudinal direction is parallel to the first direction y.

On the other hand, when the plurality of battery modules 90 are arranged along the first direction y, the gaps 28 formed in the different battery modules 90 are arranged together on the same straight line in the first direction y. Aligned so that

The base plate 60 according to the first embodiment is a cast aluminum base plate 60 including a plurality of insulating parts 70.

The insulating parts 70 extending in the first direction are spaced apart from each other and parallel to each other in the second direction x. The insulating part 70 crosses substantially the entire length of the base plate 60 along the first direction y of the base plate 60, and only a narrow edge region of the base plate 60 may be left.

Each insulator 70 is aligned with a plurality of gaps 28 between adjacent cells 80 in the plurality of battery modules 90. That is, the plurality of gaps 28 may be located above the insulating portion 80.

The insulating part 70 is made of a heat insulating polymer and is formed from the first main surface 61 of the base plate 60 from the first main surface 61 of the base plate 60 in the third direction z perpendicular to the x and y directions. Extends over the entire height of the baseplate 60 to 62.

On the other hand, the insulating portion 70 extending over the entire height of the base plate 60 may be formed through the following process.

First, the base plate 60 according to the first embodiment is provided by casting a flat aluminum base plate 60 and cutting a plurality of concave grooves in the first main surface of the flat base plate 60.

At this time, the cutting depth of the concave groove is adjusted so that the concave groove does not extend to the second main surface 62, and the recessed groove is filled with a heat insulating polymer after cutting.

After curing of the polymer, the base plate is ground in the second main surface until the filled concave groove is exposed in the second main surface 62. Through the grinding process, the concave groove extends to the second main surface, and thus the insulation portion is provided to extend over the entire height of the base plate.

By cutting the concave grooves so that the concave grooves do not extend to the second main surface 62 as described above and exposing the concave grooves on the second main surface through the grinding process, the manageability of the base plate 60 in the manufacturing process It can be improved and breakage can be effectively prevented.

Due to the heat insulating polymer, the base plate 60 is kept integral and the first direction y thermal conductivity of the base plate 60 is greater than the second direction thermal conductivity of the base plate 60. Thermal conduction in the second direction x is interrupted or suppressed at each insulation unit 70.

6 shows a schematic plan view of the battery system 100 and the base plate 60 according to the second embodiment. In the second embodiment, the battery system 100 includes a plurality of battery modules 90 and a plurality of battery cells 80 arranged as described with reference to FIGS. 4 and 5.

The base plate 60 of the second embodiment differs from the first embodiment in that each of the insulating parts 70 extends in a broken line along the first direction y, and between the insulating parts 70 in the first direction. The gaps 71 are disposed between the adjacent battery modules 90. In addition, the insulating part 70 may not extend over the entire length of the base plate 60 in the z direction perpendicular to the x and y directions.

In the second embodiment, the insulating part 70 is formed of a plurality of concave grooves 70 in the first main surface 61 of the base plate 60. The recess 70 is cut into the plane 61 of the cast aluminum baseplate 60 or the baseplate 60 is initially cast with the recess in a suitable mold.

The recess 70 may be left hollow or filled with a heat insulating material. The base plate 60 according to the second embodiment may be mechanically more stable than the first embodiment.

FIG. 7 shows a schematic side view of a battery system 100 according to a third embodiment including a plurality of battery modules 90 and a battery cell 80 as described above.

The base plate 60 is basically provided as described in connection with the first embodiment, but additionally includes a plurality of heat dissipating parts.

The heat dissipation unit is a coolant duct or a cooling channel 72 embedded in the aluminum base plate 60, and each cooling channel 72 includes a plurality of battery cells arranged in a straight line along the y direction in different battery modules 90. 80) aligned with the bottom surface (27).

In particular, the cooling channel 72 extends across the entire length of the base plate 60 along the first direction y and is configured to be connected to an external cooling circuit.

The baseplate 60 is basically manufactured as described with respect to the first embodiment, and a copper cooling channel 72 is placed in the mold before the aluminum baseplate 60 is cast.

In the formation of the insulator 70, the recess is cut between adjacent cooling channels 72.

The base plate 60 according to the third embodiment has an increased thermal conductivity and heat dissipation along the first direction y so that anisotropy with respect to thermal conductivity between the first and second directions is increased.

Thus, for example, the heat of a battery cell 80 which failed during thermal runaway is mainly transferred to the adjacent battery module 90 and is not transferred to the adjacent battery cell of the same battery module 90.

Description of the sign

10 electrode assembly 11 anode

11a: anode positive portion 12: cathode

12a: negative electrode non-coating portion 13: separator

18: first wide side 19: second wide side

21: positive terminal (first terminal) 22: negative terminal (second terminal)

25: terminal connecting member 26: case

27: bottom surface 28: gap

30: cap assembly 31: cap plate

32: injection hole 34: vent hole

37: short circuit hole 38: sealing cap

39: vent member 39a: notch

41, 42: current collector tab 43, 45: lower insulating member

54 upper insulating member 56 short circuit member

58: connecting plate 59: gasket

60: base plate 61: the first main surface

62: second main surface 70: insulation / recess groove

71: clearance gap 72: cooling channel

80: battery cell 81: first battery cell

82: second battery cell 90: battery module

100: battery system

Claims

A plurality of battery modules disposed to be spaced apart from each other in a first direction and including a plurality of battery cells arranged in a second direction, wherein the plurality of battery cells each includes an electrode assembly accommodated in a battery case having a bottom surface; And

And a base plate supporting the battery module and including a first main surface in thermal contact with a bottom surface of the battery case.

And a thermal conductivity in the first direction of the base plate is greater than a thermal conductivity in the second direction of the base plate.
The method according to claim 1,

The base plate includes a first material having a first thermal conductivity, and includes a plurality of insulation portions extending in a first direction and having a second thermal conductivity lower than the first thermal conductivity.
The method according to claim 2,

Each of the battery cases includes a first wide side surface and a second wide side surface that are vertically connected to each end of the bottom surface and aligned along the first direction.

A gap extending in the first direction is provided between the second wide side surface of the first battery cell and the first wide side surface of the second battery cell adjacent to the first battery cell with respect to the second direction.

Each of the insulating parts is aligned with the gap along the first direction.
The method according to claim 2,

And the insulating portion extends continuously across the entire length of the base plate along the first direction.
The method according to claim 2,

The insulating part extends in a broken line across the entire length of the base plate along the first direction, and the gap of the broken line is disposed between neighboring battery modules.
The method according to claim 2,

And the insulating portion extends from the first main surface of the base plate to a second main surface of the base plate opposite to the first main surface.
The method according to claim 2,

And the insulating part is a concave groove embedded in the first main surface of the base plate.
The method according to claim 7,

And the concave groove is hollow or filled with a material having the second thermal conductivity lower than the first conductivity.
The method according to claim 2,

The base plate further includes a plurality of heat dissipation parts extending in the first direction,

Each of the heat dissipating parts is aligned with at least one battery case bottom surface.
The method according to claim 9,

The heat dissipation unit includes a third material having a third thermal conductivity higher than the first thermal conductivity and the second thermal conductivity.
The method according to claim 9,

The heat dissipation unit is a battery system is integrally provided in the base plate and a cooling channel provided to guide the refrigerant.
The method according to claim 9,

And the heat dissipation unit continuously extends across the entire length of the base plate in a first direction.
An electric vehicle comprising a battery system according to any one of claims 1 to 12.