CN218731660U - Battery core and battery module - Google Patents

Abstract

The utility model relates to a battery technology field discloses an electricity core and battery module. The battery cell comprises an aluminum shell, a core package and a negative connecting sheet, wherein one end of the aluminum shell along the length direction is connected with a negative top cover, and the other end of the aluminum shell is connected with a positive top cover; the core package holding has stretched out anodal utmost point ear and negative pole utmost point ear respectively along width direction's both sides in the aluminum hull, compares in prior art anodal utmost point ear and the setting of negative pole utmost point ear branch establishing at core package length direction both ends, can shorten the conductive path, reduces the impedance of electric core, improves the power performance of electric core to promote the quick performance of filling of electric core. The positive pole lug is in contact connection with one side of the aluminum shell, so that the aluminum shell is connected with the positive pole top cover as the positive pole connecting piece, the structure is simplified, the cost is reduced, and the grouping efficiency is improved. The negative electrode connecting sheet is positioned in the aluminum shell, one end of the negative electrode connecting sheet is connected with a negative electrode lug, and the other end of the negative electrode connecting sheet is connected with the negative electrode top cover to form a conductive path, so that the battery cell can be charged and discharged.

Description

Battery core and battery module

Technical Field

The utility model relates to a battery technology field, concretely relates to electricity core and battery module.

Background

In the prior art, the length of some square batteries is generally longer, and a core package of the square batteries is formed by sequentially and alternately laminating a plurality of positive plates, a plurality of diaphragms and a plurality of negative plates. The plurality of positive plates are electrically connected with the positive electrode tabs so that the positive electrode tabs serve as positive electrode output ends, and the plurality of negative plates are electrically connected with the negative electrode tabs so that the negative electrode tabs serve as negative electrode output ends.

However, the positive electrode tab and the negative electrode tab are usually separately arranged at two ends of the core bag along the length direction, the conductive path is relatively long, and in addition, some batteries are relatively thin, and the number of layers of the electrode plates in the core bag is relatively small, so that the impedance of the battery is relatively large. The longer the battery is, the longer the length of the pole piece is, the longer the conducting path is, the larger the impedance of the battery is, i.e. the worse the power performance of the battery is, and the worse the quick charging performance of the battery is.

Therefore, it is desirable to provide a battery cell and a battery module to solve the above problems.

SUMMERY OF THE UTILITY MODEL

According to the utility model discloses an aspect, the utility model aims to provide an electricity core can shorten the conduction route, reduces the impedance of electricity core, and then improves the power performance of electricity core.

In order to achieve the purpose, the utility model discloses a following technical scheme realizes:

an electrical core, comprising:

one end of the aluminum shell along the length direction is connected with a negative electrode top cover, and the other end of the aluminum shell is connected with a positive electrode top cover;

the core bag is accommodated in the aluminum shell, a positive electrode lug and a negative electrode lug respectively extend from two sides of the core bag along the width direction, and the positive electrode lug is in contact connection with one side of the aluminum shell;

and the negative electrode connecting sheet is positioned in the aluminum shell, one end of the negative electrode connecting sheet is connected with the negative electrode lug, and the other end of the negative electrode connecting sheet is connected with the negative electrode top cover.

Preferably, the positive electrode tab is connected with the aluminum shell through laser welding.

Preferably, a plurality of welding marks are formed on the aluminum shell, and the welding marks are formed outside the aluminum shell.

Preferably, the core package comprises a plurality of layers of positive plates, a plurality of layers of negative plates and a plurality of layers of diaphragms, wherein the positive plates and the negative plates are alternately arranged in a laminated manner, and the diaphragms are arranged between the adjacent positive plates and the adjacent negative plates.

As a preferred scheme, the positive plate comprises a positive aluminum foil layer and a positive active material layer coated on part of the positive aluminum foil layer, wherein each positive aluminum foil layer is provided with a tab, and the tabs on all the positive aluminum foil layers form the positive tab;

the negative pole piece includes negative pole copper foil layer and coats in part negative pole active material layer on the negative pole copper foil layer, every all be equipped with utmost point ear, all on the negative pole copper foil layer utmost point ear on the negative pole copper foil layer is constituteed negative pole utmost point ear.

Preferably, the coating width of the negative electrode active material layer is greater than that of the positive electrode active material layer, the difference between the width of the battery cell and the coating width of the negative electrode active material layer is greater than 35mm, and the difference between the width of the battery cell and the width of the core package is less than 35mm.

Preferably, the ratio of the coating width of the negative electrode active material layer or the positive electrode active material layer to the cell impedance is 25 to 1200mm/m Ω.

As a preferred scheme, an inner protective film is wrapped outside the core bag and the negative connecting sheet, and a notch is formed in one side of the inner protective film and used for avoiding the positive electrode lug; and/or

And an insulating sheet is arranged outside one side of the inner protective film, which is close to the negative electrode connecting sheet.

Preferably, the aluminum shell is wrapped by an insulating film or an insulating coating.

Preferably, the difference between the cell length and the core package length is less than 25mm.

According to the utility model discloses an in another aspect, the utility model aims to provide a battery module still can reduce the impedance, improves the power performance, promotes and fills the performance soon.

In order to achieve the purpose, the utility model discloses a following technical scheme realizes:

the battery module comprises a battery box and the battery cell, wherein the battery cell is contained in the battery box.

The utility model has the advantages that:

the utility model provides an electric core, with anodal utmost point ear and negative pole utmost point ear branch locate the both sides of core package along width direction, compare in prior art anodal utmost point ear and negative pole utmost point ear branch establish the setting at core package length direction's both ends, can shorten the conduction path, reduce the impedance of electric core, and then improve the power performance of electric core to promote the quick-charging performance of electric core.

The utility model provides a battery module through using above-mentioned electric core, can reduce the impedance, improves the power performance, and then promotes the quick performance of filling.

Drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly and easily, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and the drawings described below are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is an exploded view of a battery cell provided in an embodiment of the present invention;

fig. 2 is a schematic view of an overall structure of a battery cell provided in an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a battery cell provided by an embodiment of the present invention after an insulating film is hidden;

fig. 4 is a schematic structural diagram of a core package according to an embodiment of the present invention;

fig. 5 is a cross-sectional view of the core pack of fig. 4 in the thickness direction;

fig. 6 is a top view of the negative electrode tabs in the core package of fig. 4.

In the figure:

1. an aluminum shell; 11. a positive electrode top cover; 12. a negative electrode top cover; 13. welding and printing;

2. a core package; 21. a positive electrode tab; 22. a negative electrode tab; 23. a positive plate; 231. a positive aluminum foil layer; 232. a positive electrode active material layer; 24. a negative plate; 241. a negative copper foil layer; 242. a negative electrode active material layer; 25. a diaphragm;

3. a negative electrode connecting sheet;

4. an inner protective film; 41. a notch;

5. an insulating sheet;

6. an insulating film.

Detailed Description

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

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood as a specific case by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used in the orientation or positional relationship shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The embodiment provides a battery module, and a plurality of battery modules can constitute the battery package, and the battery package is used for new energy automobile on, is responsible for storing and releasing energy, provides power for new energy automobile. This battery module includes battery box and a plurality of electric core, and a plurality of electric core holding are in the battery box. The battery cell is a square battery cell.

Specifically, as shown in fig. 1, the battery cell provided in this embodiment includes an aluminum casing 1, a core package 2, and a negative electrode connecting sheet 3, where one end of the aluminum casing 1 along a length direction is connected to a negative electrode top cover 12, and the other end is connected to a positive electrode top cover 11; the core bag 2 is accommodated in the aluminum shell 1, a positive electrode tab 21 and a negative electrode tab 22 respectively extend from two sides of the core bag 2 along the width direction, and the positive electrode tab 21 is in contact connection with one side of the aluminum shell 1; the negative electrode connecting sheet 3 is positioned in the aluminum shell 1 and is arranged between the aluminum shell 1 in an insulating way, one end of the negative electrode connecting sheet 3 is connected with the negative electrode lug 22, the other end of the negative electrode connecting sheet is connected with the pole on the negative electrode top cover 12, and a conductive path is integrally formed, so that the battery cell can complete the charge and discharge function.

The electric core that this embodiment provided, the length of core package 2 is greater than the width of core package 2, locates core package 2 along width direction's both sides with anodal utmost point ear 21 and negative pole utmost point ear 22 branch, compares in prior art anodal utmost point ear 21 and negative pole utmost point ear 22 branch and establishes the setting at core package 2 length direction's both ends, can shorten the conduction path, reduces the impedance of electric core, and then improves the power performance of electric core to promote the fast performance of filling of electric core. Secondly, connect anodal utmost point ear 21 direct contact on aluminum hull 1 for aluminum hull 1 is connected with anodal top cap 11 as anodal connection piece and is formed the conductive path, has saved the setting of anodal connection piece, has simplified the structure, and the cost is reduced has improved the efficiency of uniting.

Preferably, the positive electrode tab 21 is connected to the aluminum case 1 by laser welding, a plurality of welding marks 13 are formed on the aluminum case 1 and the positive electrode tab 21, and the welding marks 13 are formed outside the aluminum case 1. As shown in fig. 3. During welding, the aluminum shell 1 is directly welded outside, the operation is convenient, the connection performance is good, the production efficiency is high, and the cost is low.

It can be understood that the positive electrode tab 21 is made of aluminum, the negative electrode tab 22 is made of copper, and the aluminum shell 1 is also made of aluminum, so that the positive electrode tab 21 and the aluminum shell 1 are made of the same metal, the welding is easy, the welding effect is good, the negative electrode tab 22 and the aluminum shell 1 are made of different metals, the welding is difficult, and the welding effect is not good. Therefore, in order to meet the connection requirement and facilitate the operation, only the positive electrode tab 21 needs to be welded to the aluminum case 1.

Of course, in other embodiments, a positive connecting sheet may also be provided, the positive connecting sheet is located in the aluminum casing 1 and is insulated from the aluminum casing 1, one end of the positive connecting sheet is connected to the positive electrode tab 21, and the other end of the positive connecting sheet is connected to the positive top cover 11, so as to realize output of the positive electrode and finally form a conductive channel, so that the battery cell can smoothly perform charge and discharge functions.

Further, as shown in fig. 1, after the negative electrode connecting sheet 3 is connected to the negative electrode tab 22, the core package 2 and the negative electrode connecting sheet 3 are wrapped by the inner protective film 4, and one side of the inner protective film 4 is provided with a notch 41 for avoiding the positive electrode tab 21. The inner protective film 4 is used for insulating the negative electrode connecting sheet 3 and the core package 2 from the aluminum shell 1 respectively, so that the negative electrode connecting sheet 3 and the core package 2 are prevented from being in contact with the aluminum shell 1 to cause short circuit, and the safety of the battery cell is improved. For example, the inner protection film 4 may be a PET protection film which is relatively common in the prior art, in other embodiments, the inner protection film 4 may also be made of other materials which can realize insulation in the field, and the embodiment is not particularly limited.

Preferably, with continued reference to fig. 1, the inner protective film 4 is externally provided with an insulating sheet 5 on a side thereof adjacent to the negative electrode connecting sheet 3, and the insulating sheet 5 is located between the inner protective film 4 and the aluminum case 1, that is, the insulating sheet 5 and the negative electrode connecting sheet 3 are respectively located on both sides of the inner protective film 4. Through setting up insulating piece 5, can realize the dual insulation protection to negative pole connection piece 3, further improve insulating effect, and then further improve the security of electric core.

Further, as shown in fig. 1 and 2, the aluminum case 1 is wrapped with an insulating film 6 or an insulating coating. Insulating film 6 or insulating coating are used for insulating two adjacent electric cores, and electric core contact caused the short circuit when avoiding in groups, improve the security of battery module. For example, the insulating film 6 may be a PET protective film commonly used in the prior art, and in other embodiments, the insulating film 6 or the insulating coating may also be made of other materials or paints capable of achieving insulation in the art, which is not specifically limited in this embodiment.

Preferably, as shown in fig. 3 and fig. 4, the length of the cell is L, the length of the core package 2 is L, and a difference between the cell length L and the core package 2 length L is less than 25mm. By adopting the arrangement, the core package 2 is ensured to be longer as far as possible on the premise of being completely accommodated in the aluminum shell 1, so that the whole structure of the battery cell is more compact, and the capacity of the battery cell is larger.

Further, as shown in fig. 5, the core pack 2 includes a plurality of layers of positive electrode tabs 23, a plurality of layers of negative electrode tabs 24, and a plurality of layers of separators 25, the positive electrode tabs 23 and the negative electrode tabs 24 are alternately stacked, and the separators 25 are disposed between adjacent positive electrode tabs 23 and negative electrode tabs 24. As shown in fig. 6, the positive electrode tab 23 and the negative electrode tab 24 are both substantially rectangular in shape, taking the view of the negative electrode tab 24 as an example. In the production process of the battery core, the diaphragm 25, the positive plate 23, the diaphragm 25, the negative plate 24 and the diaphragm 25 are sequentially stacked, so that the diaphragm 25 is positioned between the positive plate 23 and the negative plate 24 to play a role in isolation, the core package 2 is obtained, the core package 2 can also be obtained after winding, then the core package 2 is placed in the aluminum shell 1, electrolyte is injected and the battery core is sealed, and finally the battery core is formed.

Specifically, with continued reference to fig. 5, the positive electrode sheet 23 includes positive electrode aluminum foil layers 231 and positive electrode active material layers 232 coated on part of the positive electrode aluminum foil layers 231, each positive electrode aluminum foil layer 231 is provided with a tab, all tabs on the positive electrode aluminum foil layers 231 jointly constitute a positive electrode tab 21 to be led out through the positive electrode tab 21, and the part of the positive electrode aluminum foil layers 231 connected with the positive electrode tab 21 is not coated with a positive electrode active material for contacting with the positive electrode tab 21 for electrical conduction. Illustratively, the positive electrode active material layer 232 may be one or more of a lithium manganate layer, a lithium cobaltate layer, a lithium iron phosphate layer, a lithium iron manganese phosphate layer, or a lithium nickel cobalt manganate layer, etc. Of course, the positive electrode active material layer 232 is not limited to the above limitation, and in other embodiments, the positive electrode active material layer 232 may also be other positive electrode active materials, as long as the positive electrode active material layer 232 can have higher structural stability and electrochemical performance, and the limitation is not specifically made in this embodiment.

Further, with continued reference to fig. 5, the negative electrode sheet 24 includes a negative electrode copper foil layer 241 and a negative electrode active material layer 242 coated on a part of the negative electrode copper foil layer 241, each negative electrode copper foil layer 241 is provided with a tab, the tabs on all the negative electrode copper foil layers 241 jointly form a negative electrode tab 22 to be led out through the negative electrode tab 22, and the part of the negative electrode copper foil layer 241 connected to the negative electrode tab 22 is not coated with a negative electrode active material for contacting with the negative electrode tab 22 for electrical conduction. Illustratively, the anode active material layer 242 may be one or more of a graphite layer, a hard carbon layer, or a soft carbon layer. Of course, the negative electrode active material layer 242 is not limited to the above limitation, and in other embodiments, the negative electrode active material layer 242 may also be made of other negative electrode active materials known in the art, such as one or more of metal lithium, silicon-carbon composite, siO, li-Sn alloy, li-Sn-O alloy, sn, snO2, and Li-Al alloy, and is not specifically limited in this embodiment.

Note that both surfaces of the positive electrode aluminum foil layer 231 are coated with the positive electrode active material layer 232, and likewise both surfaces of the negative electrode copper foil layer 241 are coated with the negative electrode active material layer 242. In the process of manufacturing the core package 2, the negative electrode active material, the optional conductive agent and the binder are generally dispersed in a solvent to form uniform negative electrode slurry, the negative electrode slurry is coated on the negative electrode copper foil layer 241, and the negative electrode sheet 24 can be obtained after the processes of drying and the like. The positive active material layer 232 has the same structure, and will not be described herein.

Preferably, the coating width of the negative active material layer 242 is greater than that of the positive active material layer 232, as shown in fig. 3, 4 and 6, the cell width is H, the core 2 width is H1, the coating width of the negative active material layer 242 is H2, the difference between H and H2 is greater than 35mm, and the difference between H and H1 is less than 35mm. While ensuring the compact structure of the whole cell, enough space is left in the aluminum shell 1 to accommodate the positive electrode tab 21 and the negative electrode tab 22.

Further, the ratio of the coating width h2 of the negative electrode active material layer 242 to the cell impedance is 25 to 1200mm/m Ω. Illustratively, the ratio is preferably 70mm/m Ω, and tests show that the quick charging capacity of the battery cell is better at the ratio.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (11)

1. Electric core, its characterized in that includes:

the aluminum shell (1), one end of the aluminum shell (1) along the length direction is connected with a negative top cover (12), and the other end is connected with a positive top cover (11);

the core bag (2) is accommodated in the aluminum shell (1), a positive electrode tab (21) and a negative electrode tab (22) respectively extend out of two sides of the core bag (2) along the width direction, and the positive electrode tab (21) is in contact connection with one side of the aluminum shell (1);

and the negative electrode connecting piece (3) is positioned in the aluminum shell (1), one end of the negative electrode connecting piece is connected with the negative electrode lug (22), and the other end of the negative electrode connecting piece is connected with the negative electrode top cover (12).

2. The electrical core according to claim 1, characterized in that the positive electrode tab (21) is connected to the aluminum casing (1) by laser welding.

3. The battery cell of claim 2, wherein a plurality of welding imprints (13) are formed on the aluminum shell (1), and the welding imprints (13) are formed outside the aluminum shell (1).

4. The battery core according to claim 1, wherein the core package (2) comprises a plurality of layers of positive electrode sheets (23), a plurality of layers of negative electrode sheets (24) and a plurality of layers of separators (25), the positive electrode sheets (23) and the negative electrode sheets (24) are alternately arranged in a lamination manner, and the separators (25) are disposed between the adjacent positive electrode sheets (23) and the adjacent negative electrode sheets (24).

5. The battery cell of claim 4, wherein the positive electrode sheet (23) comprises a positive electrode aluminum foil layer (231) and a positive electrode active material layer (232) coated on a part of the positive electrode aluminum foil layer (231), each positive electrode aluminum foil layer (231) is provided with a tab, and the tabs on all the positive electrode aluminum foil layers (231) form the positive electrode tab (21);

negative pole piece (24) include negative pole copper foil layer (241) and coat in part negative pole active material layer (242) on negative pole copper foil layer (241), every all be equipped with utmost point ear on negative pole copper foil layer (241), all utmost point ear on negative pole copper foil layer (241) is constituteed negative pole utmost point ear (22).

6. The electrical core of claim 5, wherein the coating width of the negative active material layer (242) is greater than the coating width of the positive active material layer (232), the difference between the width of the electrical core and the coating width of the negative active material layer (242) is greater than 3.5mm, and the difference between the width of the electrical core and the width of the core package (2) is less than 3.5mm.

7. The cell of claim 6, wherein a ratio of a coating width of the negative active material layer (242) to the cell impedance is 25-1200 mm/m Ω.

8. The battery cell of any one of claims 1 to 7, wherein the core package (2) and the negative electrode connecting sheet (3) are wrapped by an inner protective film (4), and one side of the inner protective film (4) is provided with a notch (41) for avoiding the positive electrode tab (21); and/or

And an insulating sheet (5) is arranged outside one side of the inner protective film (4) close to the negative electrode connecting sheet (3).

9. The electrical core according to any of claims 1 to 7, characterized in that the aluminum casing (1) is externally wrapped with an insulating film (6) or an insulating coating.

10. The electrical core according to any of claims 1 to 7, wherein the difference between the length of the electrical core and the length of the core package (2) is less than 25mm.

11. A battery module comprising a battery box, further comprising the electrical core of any of claims 1-10 housed within the battery box.

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