CN112349991A

CN112349991A - Battery energy storage device

Info

Publication number: CN112349991A
Application number: CN202010959249.0A
Authority: CN
Inventors: 蔡伟华; 雷琪玮; 李晓倩; 郭磊; 郭启涛
Original assignee: BYD Co Ltd
Current assignee: Shaoxing Fudi Battery Co ltd; BYD Co Ltd
Priority date: 2020-09-14
Filing date: 2020-09-14
Publication date: 2021-02-09
Anticipated expiration: 2040-09-14
Also published as: CN112349991B

Abstract

The application discloses battery energy memory, this battery energy memory include box and a plurality of electric core. The battery cell is sheet-shaped, and the surfaces of the two sides of the battery cell in the thickness direction are main heat dissipation surfaces of the battery cell. The box body comprises a bottom plate and a plurality of cooling plates arranged on the bottom plate; and an accommodating space for accommodating the battery cell is formed between every two adjacent cooling plates. The battery cell is installed in the accommodating space, and the main radiating surfaces on two sides of the battery cell are respectively attached to the two adjacent cooling plates. The application provides a battery energy memory's electric core back on the box of packing into, the main heat dissipation face of electric core both sides all laminates mutually with the cooling plate, has improved the heat dispersion of electric core for the whole heat dissipation of electric core is even, and the different position difference in temperature of electric core is little, has prolonged electric core and even battery energy memory's life-span.

Description

Battery energy storage device

Technical Field

The application relates to the technical field of new energy equipment, in particular to a battery energy storage device.

Background

In recent years, with the explosion of new energy industries, the technology of lithium ion battery systems used in new energy industries is being rapidly updated iteratively. For lithium ion battery systems, high energy density, high safety, high reliability and low cost are constant topics.

The patent application No. 202010075473.3 discloses a lithium ion battery electrochemical energy storage system without a modular structure. The battery cell module is used for replacing a traditional module, one or more battery cells are connected and then put into a groove of a lower box tray as the battery cell module, and the battery cells are fixed by the groove type fixing module. The technical scheme of the patent has the problem of low durability: the liquid cooling plate is arranged at the bottom of the lower box body, the battery core is cooled only through the narrow surface, and the temperature difference between the upper layer and the lower layer of the battery pack is large, so that the local temperature difference of the battery core is large. The inconsistent temperature of each battery cell leads the life decay rate of each battery cell to be inconsistent. The capacity of the battery energy storage device is determined by the battery cell with the lowest capacity in the system, so that the service life of the energy storage system is directly influenced by the excessively high attenuation rate of part of the battery cells, and waste is caused.

Disclosure of Invention

The embodiment of the disclosure provides a battery energy storage device, which improves the heat dissipation performance of an electric core and prolongs the service life of the electric core.

In order to solve the above problems, the present disclosure adopts the following technical solutions:

a battery energy storage device, comprising:

the battery cell comprises a plurality of battery cells, wherein the battery cells are sheet-shaped, and the surfaces of two sides of each battery cell in the thickness direction are main heat dissipation surfaces of the battery cells;

a box comprising a base plate and a plurality of cooling plates disposed on the base plate; an accommodating space for accommodating the battery cell is formed between every two adjacent cooling plates;

the battery cell is installed in the accommodating space, and the main radiating surfaces on two sides of the battery cell are respectively attached to the two adjacent cooling plates.

Optionally, a plurality of battery cells are arranged between two adjacent cooling plates; the battery cores are sequentially arranged along the length direction of the cooling plate;

positive electrodes and negative electrodes are respectively arranged at two ends of each electric core along the length direction of the cooling plate, and the positive electrodes and the negative electrodes of two adjacent electric cores are opposite in position;

the positive electrodes and the negative electrodes of two adjacent battery cells are connected through a first connecting sheet.

Optionally, a plurality of middle isolation components are arranged on the cooling plate at intervals along the length direction;

two adjacent electric cores are separated by the middle isolation component; the first connecting piece is arranged through the middle isolation part.

Optionally, the middle insulation part comprises a fixing part and an insulating part;

the fixing piece is fixedly connected with the cooling plate; the insulating part is provided with a connecting groove, and the insulating part is sleeved on the fixed part through the connecting groove;

the first connecting piece penetrates through the insulating piece.

Optionally, the insulator comprises a first block and a second block;

the first block body is provided with a notch groove; the first connecting sheet penetrates through the notch groove;

the second block body is covered on the first block body to seal the top opening of the notch groove.

Optionally, both side surfaces of the battery cell in the length direction of the cooling plate are arc convex surfaces;

two sides of the middle isolation part are respectively provided with a first arc concave surface;

the arc convex surface of the battery cell is attached to the first arc concave surface.

Optionally, at the end of the cooling plate, two battery cells on two sides of the cooling plate are connected through a second connecting sheet; the second connecting piece extends from one side of the cooling plate to the other side of the cooling plate.

Optionally, the battery energy storage device comprises an end isolation member; the end spacer has a slit; the end isolation component is clamped at the end of the cooling plate through the slit part;

the second connecting piece is arranged to penetrate the end isolation part.

Optionally, the end isolation member comprises a third block and a fourth block;

the third block body is provided with a slit groove arranged around the circumferential side of the slit part; the second connecting piece penetrates through the slit groove;

the fourth block body is covered on the third block body and closes the top opening of the slit groove.

a second arc concave surface is arranged on one surface, facing the battery core, of the end isolation component;

and the arc convex surface of the battery cell is attached to the second arc concave surface.

In a second aspect, the present application also provides an electronic device having the above detection module.

The technical scheme adopted by the embodiment of the disclosure can achieve the following beneficial effects:

the application provides a battery energy memory's electric core back on the box of packing into, the main heat dissipation face of electric core both sides all laminates mutually with the cooling plate, has improved the heat dispersion of electric core for the whole heat dissipation of electric core is even, and the different position difference in temperature of electric core is little, has prolonged the life of electric core.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and not to limit the disclosure. In the drawings:

fig. 1 is an exploded view of a battery energy storage device provided in an embodiment of the present application;

fig. 2 is an exploded view of a case portion of a battery energy storage device provided in an embodiment of the present application;

fig. 3 is a schematic view of a connection structure of two adjacent battery cells in the battery energy storage device provided in the embodiment of the present application;

FIG. 4 is an enlarged view of portion A of FIG. 3;

fig. 5 is a schematic view of a partial structure of a battery energy storage device according to an embodiment of the present disclosure;

fig. 6 is a schematic perspective view of a box portion of a battery energy storage device according to an embodiment of the present disclosure;

FIG. 7 is an enlarged view of portion C of FIG. 6;

FIG. 8 is an enlarged view of portion D of FIG. 6;

fig. 9 is a schematic view of a matching structure of two battery cells on two sides of the same cooling plate in the battery energy storage device according to the embodiment of the present application;

FIG. 10 is a schematic view of the second connecting piece in the position B in FIG. 9;

fig. 11 is a partial structural view of a top view of a battery energy storage device according to an embodiment of the present application.

In the figure:

1-a box body;

11-a base plate;

111-upper floor;

112-middle layer liquid cooling plate;

113-a lower floor;

12-a cooling plate;

2-covering the upper cover;

a 3-BMS hardware module;

4-electric core;

41-positive electrode;

42-a negative electrode;

43-arc convex surface;

5-a first connecting piece;

6-a second connecting sheet;

61-end piece;

62-a lateral panel;

7-a middle spacer member;

71-a fixture;

72-an insulator;

72 a-first arc concavity;

721-a first block;

721 a-notch groove;

722-a second block;

8-an end spacer member;

8 a-a second arc concave surface;

8 b-a seam cut;

81-a third block;

811-slitting groove;

82-fourth block.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, the following embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings. It is to be understood that the described embodiments are merely a subset of the disclosed embodiments and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

The terms first, second and the like in the description and in the claims of the present disclosure are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that embodiments of the disclosure can be practiced in sequences other than those illustrated or described herein. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

Technical solutions disclosed in the embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

Referring to fig. 1 to 11, an embodiment of the present application provides a battery energy storage device, including: box 1, upper cover 2, BMS hardware module 3 and a plurality of electric core 4. The battery cores 4 are arranged on the box body 1, and the upper cover 2 is arranged on the box body 1 and covers the battery cores 4 on the box body 1. The battery cell 4 is sheet-shaped, and the areas of the surfaces of the two sides of the battery cell 4 in the thickness direction are the largest, and are the main heat dissipation surfaces of the battery cell 4. The case 1 includes a bottom plate 11 and a plurality of cooling plates 12 provided on the bottom plate 11. The cooling plates 12 are arranged in parallel, and a containing space for containing the battery core 4 is formed between two adjacent cooling plates 12. Electric core 4 insert install in the accommodation space, just the main radiating surface of electric core 4 both sides is laminated with two adjacent cooling plates 12 respectively mutually to increased electric core 4's heat radiating area, the cooling plate 12 of electric core 4 both sides absorbs the heat of the main radiating surface of electric core 4 both sides simultaneously, made electric core 4 whole heat dissipation even, the different position difference in temperature of electric core is little, long service life. Each electric core 4 all dispels the heat through the main radiating surface of both sides among the battery energy memory of this application, therefore the heat dissipation is fast, and each electric core 4's the difference in temperature is little, guarantees as far as possible that each electric core 4 life-span decay rate is unanimous, extension battery energy memory's whole life.

The battery energy storage device has the characteristics of high energy density, high durability, high safety and high reliability, and can be used for both electric automobiles and emergency energy storage power stations.

Optionally, the box body 1 is made of an aluminum alloy material, so that the box body has good heat conduction and heat dissipation performance. Referring to fig. 1 and 2, the bottom plate of the cabinet 1 includes three layers of an upper layer bottom plate 111, a middle layer liquid cooling plate 112 and a lower layer bottom plate 113. The three-layer structure is welded and fixed with each other. The upper floor 111 is provided with a cooling plate 12. It should be noted that the cooling plate 12 may also be made of an aluminum alloy material and fixedly connected to the upper bottom plate 111. A flow channel for the circulation of the cooling medium is arranged on the middle layer liquid cooling plate 112, and a cooling medium inlet and a cooling medium outlet which are communicated with the flow channel are arranged on the middle layer liquid cooling plate 112. The lower bottom plate 113 is welded to the bottom surface of the middle liquid-cooled plate 112. The heat generated by the battery cell 4 in the working process is transferred to the middle-layer liquid cooling plate 112 by the cooling plate 12 made of aluminum alloy material for heat exchange, so as to control the temperature of the battery cell 4 to work in a proper range.

Optionally, a plurality of battery cells 4 are disposed between two adjacent cooling plates 12, and each battery cell 4 is sequentially disposed along the length direction of the cooling plate 12. In this way, a plurality of rows of the electric cores 4 arranged in parallel are formed on the box body 1, and each electric core 4 is inserted into the gap between the two cooling plates 12 through a narrow surface, so that the assembly structure is compact.

As shown in fig. 3, positive electrodes 41 and negative electrodes 42 are respectively disposed at two ends of the battery cells 4 along the length direction of the cooling plate 12, and the positive electrodes 41 and the negative electrodes 42 of two adjacent battery cells 4 are opposite to each other. The positive electrodes 41 and the negative electrodes 42 of two adjacent battery cells 4 are connected by the first connection tab 5. In this embodiment, the battery cell 4 is provided with the positive electrode 41 and the negative electrode 42 on the end faces of the two ends along the length direction of the cooling plate 12, so that the main heat dissipation surfaces on the two sides of the battery cell 4 are completely attached to and contacted with the cooling plate 12. Each electric core 4 is end to end along cooling plate 12 length direction in proper order, rather than connecting along cooling plate 12 thickness direction, consequently need not set up the structure of dodging first connection piece on cooling plate 12 for cooling plate 12 is surperficial confined monoblock structure, does benefit to cooling plate 12 and the complete laminating of the main radiating surface of electric core 4, improves the cooling efficiency of electric core 4.

Optionally, referring to fig. 5, 6 and 7, a plurality of middle isolation components are arranged on the cooling plate 12 at intervals along the length direction; two adjacent battery cores 4 are separated by the middle isolation component 7; the first connecting web 5 is arranged through the central separating element. Each middle part isolation part divides the accommodating space between two cooling plates 12 into a plurality of independent small spaces, each small space is only used for accommodating one battery cell 4, and the main radiating surfaces on the two sides of the battery cell 4 are convenient to be respectively attached to the two cooling plates 12 on the two sides.

Specifically, the middle isolation member 7 includes a fixing member (71) and an insulating member 72. The fixing piece (71) is fixedly connected with the cooling plate 12; the insulation part is provided with a connecting groove, the insulation part 72 is sleeved on the fixing part (71) through the connecting groove, and the first connecting piece 5 penetrates through the insulation part 72. In this embodiment, the mounting of the insulator is facilitated by the provision of the fixing member (71). As shown in fig. 5, 6 and 7, the cooling plate 12 is provided with a plurality of fixing members 71 at intervals along the longitudinal direction. The fixing member 71 extends in a direction perpendicular to the cooling plate 12. Each fixing member 71 divides the accommodating space between the two cooling plates 12 into a plurality of independent small spaces, each small space is only used for accommodating one battery cell 4, and the main radiating surfaces on the two sides of the battery cell 4 are conveniently attached to the two cooling plates 12 on the two sides respectively. In the length direction of the cooling plate 12, two adjacent battery cells 4 are separated by the fixing member 71, the fixing members 71 on two adjacent cooling plates 12 are opposite to each other with a gap therebetween, the first connecting piece 5 passes through the gap, and two ends of the first connecting piece are respectively connected with two battery cells 4.

Specifically, the fixing parts 71 of two adjacent cooling plates 12 are opposite, and the fixing parts 71 on the two cooling plates 12 respectively protrude oppositely to form an isolation rib structure. The fixing member 71 may be made of an aluminum alloy material and formed integrally with the cooling plate 12. The fixing member 71 has a function of enhancing the structural strength of the cooling plate 12 and improving the structural strength of the case 1, in addition to a function of facilitating the installation of the insulating member 72. A gap is formed between two opposite fixing pieces 71 on the two cooling plates 12, so that the first connecting piece 5 can pass through to electrically connect two adjacent electric cores 4. Referring to fig. 4, the first connecting piece 5 is provided with two through slots, the positive electrode 41 of one cell 4 passes through one through slot and is bent, the negative electrode 42 of the other cell 4 passes through the other through slot and is bent, and finally, the two electrodes and the first connecting piece 5 are welded and fixed.

Alternatively, referring to fig. 5 and 7, the battery energy storage device includes an insulating member 72, and the insulating member 72 is disposed between the two cooling plates 12 and covers the fixing member 71.

In this embodiment, the insulating member 72 is provided between two adjacent battery cells 4, and prevents a short-circuit fault from occurring at the connection between the two battery cells 4. Specifically, the insulating member 72 needs to perform insulation protection on the peripheral side structure of the first connecting plate 5, and particularly needs to perform insulation isolation on the fixing member 71, so as to prevent the fixing member 71 and the insulating member 72 from being conducted to cause an accident. The insulating member 72 may be provided with a recessed coupling groove into which the fixing member 71 is inserted when the insulating member 72 is coupled to the cooling plate 12, and the insulating member separates the fixing member 71 from the first coupling piece 5. In addition, the insulating member can further shield the wall surfaces of the cooling plate 12 on both sides of the fixing member 71, so as to prevent the first connecting piece 5 from contacting the wall surfaces. Specifically, a first connection surface and a second connection surface are provided on the insulating member at both sides of the connection groove, and the first connection surface and the second connection surface are respectively attached to the wall surfaces of the cooling plate 12 at both sides of the fixing member 71, thereby preventing the first connection piece 5 from contacting the wall surfaces to cause a short circuit failure. The fixing piece 71 is arranged to facilitate the installation of the insulating piece 72, and the insulating piece 72 is installed on the fixing piece 71 in a limiting mode.

Alternatively, referring to fig. 5 and 7, in order to facilitate the assembling process of the insulator 72, the insulator 72 includes a first block 721 and a second block 722. The first block 721 is installed on the fixing member 71 between the two cooling plates 12, and the first block 721 contacts with the surface of the base plate 11, the first block 721 is provided with a notch 721a, the two battery cells 4 are connected by the first connecting piece 5 and then placed between the two cooling plates 12 and located on two sides of the first block 721 respectively, the first connecting piece 5 between the two battery cells 4 is inserted into the notch 721a from the top opening of the notch 721a, and the notch 721a plays a role in supporting and clamping the first connecting piece 5, thereby improving the assembly stability. Finally, the second block body 722 is covered on the first block body 721 to close the top opening of the slit slot 721a, and the top of the first connection tab 5 is isolated, so that the first connection tab 5 is prevented from being electrically conducted with the top structure of the battery energy storage device and short-circuit failure occurs. The first block body 721 and the second block body 722 are both provided with a connecting groove, and the connecting groove can be sleeved on the fixing member 71 to realize rapid assembly and positioning of the first block body 721 and the second block body 722.

Referring to fig. 5, both side surfaces of the electric core 4 in the length direction of the cooling plate 12 are arc convex surfaces 43, and both sides of the middle separator 7, such as the insulator 72, are respectively provided with a first arc concave surface 72 a; the arc convex surface 43 of the battery cell 4 is attached to the first arc concave surface 72 a. In this embodiment, the arc convex surfaces 43 on both sides of the battery are inserted into the first arc concave surface 72a on the insulating member 72, so that the attaching support performance is better, and the assembly stability of the battery core 4 is improved. The first block 721 and the second block 722 are both provided with a first arc concave 72a, and the first arc concave on the first block 721 and the second block 722 are smoothly spliced to form an integral arc concave effect.

In the embodiment of the application, each battery cell 4 between two adjacent cooling plates 12 is serially connected through the first connecting sheet 5, and the first connecting sheet is a straight sheet body, so that the battery cells 4 arranged along a straight line are conveniently connected. The two electrical cores 4 on both sides of the end of the cooling plate 12 can no longer be connected by the straight first connecting web 5, for which the second connecting web 6 is provided. The second connecting sheet 6 is of a U-shaped structure, and is convenient to connect the two battery cores 4 on two sides of the cooling plate 12. Specifically, as shown in fig. 9 and 10, the second connecting piece 6 includes an end piece 61 disposed on one side of the end of the cooling plate 12 and two side pieces 62 disposed on two sides of the end piece 61, and the two side pieces 62 are respectively connected to the two electric cores 4 on two sides of the end of the cooling plate 12. It should be noted that, in the battery energy storage device of the present application, at one side end of the cooling plate 12, a row of battery cells 4 in a direction perpendicular to the cooling plate 12 are not sequentially connected by the second connection sheet 6, but every two battery cells 4 form a group, the two battery cells 4 in a group are connected by the second connection sheet 6, and the battery cells 4 in different groups are not connected.

Alternatively, as shown in fig. 1, 8 and 11, the battery energy storage device includes an end spacer member 8; the end spacer 8 has a slit portion 8 b; the end spacer 8 is held at the end of the cooling plate 12 by the slit portion 8b, so that the end spacer 8 is fixed to the cooling plate 12. The second connecting piece 6 is arranged through the end spacer 8. Wherein the end spacer 8 is made of an insulating material.

Specifically, the end isolation component 8 includes a third block 81 and a fourth block 82, the second mounting portion includes a slit groove 811 formed around the slit portion 8b on the third block 81, the slit groove 811 has an open top, two ends of the slit groove 811 are respectively communicated to two accommodation spaces on two sides of the same cooling plate 12, the slit groove 811 is a U-shaped groove and is matched with the shape of the second connecting piece 6, and when the second connecting piece 6 is disposed in the slit groove 811, the slit groove 811 can also play a role in clamping and fixing the second connecting piece 6. Since the slit groove 811 has a top opening and the second connecting piece 6 is short-circuited in contact with an external structure, the fourth block 82 in this application is placed on the third block 81 to close the top opening of the slit groove 811. The third block 81 and the fourth block 82 are each provided with a slit portion 8b, first the third block 81 is sandwiched on the cooling plate 12 by its slit portion 8b with the bottom of the third block 81 in supporting contact with the floor surface, and then the fourth block 82 is sandwiched on the cooling plate 12 above the third block 81 by its slit portion 8b to close the top opening of the slit groove 811 in the third block 81.

Optionally, both side surfaces of the battery cell 4 in the length direction of the cooling plate 12 are arc convex surfaces 43. Tip isolating part 8 orientation the one side of electricity core 4 is provided with second circular arc concave 8a, and the circular arc convex surface 43 of electricity core 4 tip inserts on the second circular arc concave 8a on the tip isolating part 8, and laminating support nature is better, has improved the assembly stability of electricity core 4. Wherein, the third block 81 and the fourth block 82 are both provided with a second arc concave surface, and the second arc concave surfaces of the third block 81 and the fourth block 82 are smoothly spliced to form an integral concave effect.

The following provides the assembly process of the battery energy storage device provided by the embodiment of the application:

the method comprises the following steps: welding an upper layer bottom plate 111, a middle layer liquid cooling plate 112 and a lower layer bottom plate 113 of the box body 1; wherein the upper floor 111 has a cooling plate 12 thereon;

step two: the first block 721 and the third block 81 are loaded on the cooling plate 12 and the upper base plate 111;

step three: all the battery cells 4 are connected in series and welded;

step four: the welded battery cells 4 are sequentially placed in the installation space between the cooling plates 12, the first connecting piece 5 is placed in the first block 721, and the second connecting piece 6 is placed in the third block 81;

step five: mounting the second block 722 and the fourth block 82;

step six: assembling the BMS hardware module 3, the wire harness and the upper cover 2 to complete the assembly.

It should be noted that, the sequence of some steps in the above assembly process may be adjusted, and the final assembly effect is not affected, for example: the original step three can be changed into the step one, and the original step one and the step two can be changed into the step two and the step three respectively.

The technical scheme provided by the embodiment of the application has the following beneficial effects:

firstly, the method comprises the following steps: the battery energy storage device is high in temperature consistency and long in service life. The cooling plate 12 on the box body 1 is in close contact with the main heat dissipation surface of the battery cell 4, and can quickly transfer the heat generated by the battery cell 4 to the middle-layer liquid cooling plate 112, so that each battery cell 4 is sufficiently cooled.

Secondly, the method comprises the following steps: the battery energy memory's of this application integrated level is high, compares 4 modules of traditional electric core, and the battery energy memory's of this application space utilization improves more than 90%, and energy density has obtained the promotion.

Thirdly, the method comprises the following steps: the battery energy storage device of the application has high safety, each battery cell 4 can be placed in an independent area, the cooling plate 12 transversely arranged and the middle isolation component 7 vertically arranged have the effect of supporting the battery cells 4, and the strength of mechanical extrusion is improved. The connection between the electric cores 4 is insulated and protected, and the short circuit risk is reduced. Electric core 4 has received cooling plate 12 and middle part separator 7's restraint on box 1, prevents that electric core 4 from leading to box 1 structural failure at the ageing in-process inflation of full life cycle for battery energy memory's security obtains further promotion.

While the present disclosure has been described with reference to the embodiments illustrated in the drawings, which are intended to be illustrative rather than restrictive, it will be apparent to those of ordinary skill in the art in light of the present disclosure that many more modifications may be made without departing from the spirit of the disclosure and the scope of the appended claims.

Claims

1. A battery energy storage device, comprising:

the battery cell comprises a plurality of battery cells (4), wherein the battery cells (4) are sheet-shaped, and the surfaces of two sides of each battery cell (4) along the thickness direction are main heat dissipation surfaces of the battery cells (4);

the refrigerator comprises a box body (1), wherein the box body (1) comprises a bottom plate (11) and a plurality of cooling plates (12) arranged on the bottom plate (11); an accommodating space for accommodating the battery cell (4) is formed between every two adjacent cooling plates (12);

the battery cell (4) is installed in the accommodating space, and the main radiating surfaces on two sides of the battery cell (4) are respectively attached to the two adjacent cooling plates (12).

2. The battery energy storage device according to claim 1, wherein a plurality of cells (4) are arranged between two adjacent cooling plates (12); the battery cores (4) are sequentially arranged along the length direction of the cooling plate (12);

two ends of each electric core (4) along the length direction of the cooling plate (12) are respectively provided with a positive electrode (41) and a negative electrode (42), and the positive electrodes (41) and the negative electrodes (42) of two adjacent electric cores (4) are opposite in position;

the positive electrodes (41) and the negative electrodes (42) of two adjacent battery cells (4) are connected through a first connecting sheet (5).

3. A battery energy storage device according to claim 2, wherein a plurality of intermediate isolation members (7) are provided on the cooling plate (12) at intervals in the length direction;

two adjacent electric cores (4) are separated by the middle isolation component (7); the first connecting piece (5) is arranged through the middle isolation part (7).

4. A battery energy storage device according to claim 3, characterized in that said middle separator member (7) comprises a fixing member (71) and an insulating member (72);

the fixing piece (71) is fixedly connected with the cooling plate (12); the insulating part (72) is provided with a connecting groove, and the insulating part (72) is sleeved on the fixing part (71) through the connecting groove;

the first connecting piece (5) is arranged through the insulating part (72).

5. A battery energy storage device as claimed in claim 4, characterized in that said insulating member (72) comprises a first block (721) and a second block (722);

the first block body (721) is provided with a notch groove (721 a); the first connecting piece (5) is arranged through the notch groove (721 a);

the second block body (722) is covered on the first block body (721) to close the top opening of the notch groove (721 a).

6. The battery energy storage device according to claim 3, wherein both side surfaces of the battery core (4) along the length direction of the cooling plate (12) are arc convex surfaces (43);

two sides of the middle isolation part (7) are respectively provided with a first arc concave surface (72 a);

the arc convex surface (43) of the battery cell (4) is attached to the first arc concave surface (72 a).

7. The battery energy storage device according to claim 1, characterized in that at the end of the cooling plate (12), two cells (4) on both sides of the cooling plate (12) are connected by a second connecting piece (6); the second connecting piece (6) extends from one side of the cooling plate (12) to the other side of the cooling plate (12).

8. A battery energy storage device according to claim 7, characterized in that it comprises an end isolation member (8); the end spacer member (8) has a slit part (8 b); the end spacer member (8) is held at the end of the cooling plate (12) by the slit part (8 b);

the second connecting piece (6) penetrates through the end isolation part (8).

9. A battery energy storage device according to claim 8, characterized in that said end separator member (8) comprises a third block (81) and a fourth block (82);

a slit groove (811) provided around the slit part (8b) on the third block (81); the second connecting piece (6) penetrates through the slit groove (811);

the fourth block body (82) is covered on the third block body (81) and closes the top opening of the slit groove (811).

10. The battery energy storage device according to claim 8, wherein both side surfaces of the battery core (4) along the length direction of the cooling plate (12) are arc convex surfaces (43);

a second arc concave surface (8a) is arranged on one surface, facing the battery core (4), of the end part isolation component (8);

and the arc convex surface (43) of the battery cell (4) is attached to the second arc concave surface (8 a).