CN210897512U - Battery cell and lithium battery - Google Patents

Abstract

This application provides a battery cell and a lithium battery. The battery cell includes: a housing; a core disposed within the housing, with tab terminals disposed on the end face of the core; and a cover plate that mates with the end face of the core with the tab terminals, the cover plate having cell terminals disposed thereon, and terminal guide grooves provided on the cell terminals for the tab terminals to pass through. This application avoids the use of bending tabs, thereby improving the space utilization within the housing, increasing the energy density of the cell, and enhancing the performance of the cell.

Description

A kind of battery cell and lithium battery

technical field

The present application relates to the technical field of lithium ion batteries, and in particular, to a battery cell and a lithium ion battery including the battery cell.

Background technique

In recent years, with the rapid development of lithium-ion power battery technology, the penetration rate of new energy vehicles is also increasing. Concerns about the decline in the cruising range of new energy vehicles are also growing. For power battery companies, how to produce batteries with high energy density, high performance and high cycle life determines whether the company can capture more customers and enhance its competitiveness.

At present, in the industry, the design solutions for square aluminum shell batteries can be roughly divided into two types, one is to have terminals at one end, and the other is to have terminals at both ends. Among them, the solution with terminals at both ends has a more uniform current density flowing through the battery during the battery cycle, and the performance of the active material on the surface of the electrode sheet inside the battery is more uniform, and the battery performance is more excellent.

However, in the existing design scheme, the connection between the winding core and the top cover mostly adopts the method of ultrasonic welding the tabs and connecting pieces and then welding with the terminals of the top cover. Most of the ears are in a bent state. In order to leave a part of the space between the end face of the winding core and the surface of the top cover, a part of the space utilization rate will be sacrificed in this direction.

Utility model content

The technical problem to be solved by the present application is the reduction of the utilization rate of the internal space of the housing due to the bent tabs occupying the internal space of the housing.

In order to solve the above technical problems, the present application discloses a battery cell, comprising: a casing; a winding core, which is placed in the casing, and the end surface of the winding core is provided with tab terminals; The winding core is matched with the end faces provided with the tab terminals, the cover plate is provided with cell terminals, and the cell terminals are provided with terminal guide grooves for the tab terminals to penetrate.

Optionally, an insulating material is integrated on a surface of the cover plate that matches the end surface of the winding core, and the terminal guide groove also penetrates the insulating material.

Optionally, the insulating material is further provided with a plurality of hollow structures.

Optionally, there are at least two tab terminals, which are respectively disposed on two opposite end faces of the winding core.

Optionally, the tab terminal includes a positive tab terminal and a negative tab terminal, the two opposite end faces are the two end faces in the height direction or the width direction of the winding core, and the positive tab terminal and the negative tab terminal are placed in the middle, Concentrically offset or non-concentrically offset on the two opposite end faces.

Optionally, the battery core terminal is sealed with the tab terminal.

The present application also discloses a lithium battery including the above-mentioned battery cell.

Compared with the prior art, the technical solution of the present application has at least the following beneficial effects:

Terminal guide grooves are arranged on the cell terminals of the cover plate. After the cover plate is assembled with the shell, the tab terminals on the winding core are inserted into the terminal guide grooves to connect with the cell terminals, so as to avoid bending the tabs in the shell. , thereby improving the space utilization rate inside the casing, increasing the energy density of the cell, and improving the performance of the cell.

Since the bending and compression of the tabs during processing are avoided, the chances of the tabs being in contact with the winding core again after the tabs are compressed can be avoided, and the risk of short-circuiting between the tabs and the pole pieces caused by excessive compression is reduced.

Since the bending of the tabs during processing is avoided, the connection distance between the winding core and the terminal of the cover plate can be effectively reduced, the internal resistance of the connecting components can be greatly reduced, and the tabs and connections originally inside the cell can be connected. The chips are all integrated into the top cover terminals to improve the heat generation of the cells during the cycle and rate discharge process, and further improve the life and performance of the cells.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic diagram of the appearance structure of a battery cell according to an embodiment of the application;

FIG. 2 is a schematic structural diagram of the winding core of the battery cell according to the embodiment of the application being loaded into the casing;

3 is a schematic diagram of an assembly structure of a cover plate and a casing of a battery cell according to an embodiment of the present application;

4A and 4B are schematic views of the front view and partial structure of the assembled battery cells according to the embodiments of the present application;

5A to FIG. 5E are schematic diagrams showing examples of positions of cell terminals and tab terminals of a battery cell according to an embodiment of the present application.

The following supplementary descriptions are provided for the accompanying drawings:

1-cell; 11-positive terminal; 12-negative terminal;

2-roll core; 21-positive ear terminal; 22-negative ear terminal; 3-shell;

4- Negative terminal cover; 41- Negative terminal guide groove; 42- Negative cover plastic;

5-positive end cover; 51-positive terminal guide groove; 52-positive cover plastic; 521-hollow hole;

6a-center tab terminal in height direction H; 6b-concentric offset tab terminal in height direction H; 6c-center tab terminal in width direction W; 6d-different center offset in width direction W Set the tab terminal; 6e-concentric offset tab terminal in the width direction W.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of this application.

In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the purpose of It is convenient to describe the application and to simplify the description, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the application. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. Also, the terms "first," "second," etc. are used to distinguish between similar objects, and are not necessarily used to describe a particular order or precedence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein.

In order to solve the technical problem that the bent tabs occupy the internal space of the casing in the related art, the technical solution of the present application provides a battery cell, by threading the pre-processed winding core tabs into a battery cell with a penetrating guide groove. The top cover terminal is then sealed to achieve the purpose of not needing to fold the tabs and maximizing the use of the cell space.

The present application will be described in detail below with reference to the embodiments and the accompanying drawings. The embodiments of the present application take a square aluminum shell battery with terminals at both ends as an example. Those skilled in the art can understand that in practical applications, it can also be applied to a single battery as required. Terminal or multi-terminal (more than two) tab terminal and cell terminal assembly solution.

Referring to FIG. 1 , the battery cell 1 of the embodiment of the present application includes two cell terminals: a positive terminal 11 and a negative terminal 12 , which are respectively disposed on opposite end surfaces of the battery cell 1 .

The battery cell 1 shown in FIG. 1 includes a winding core, a casing and a cover plate. Specifically, please refer to FIG. 2 and FIG. 3 in combination. In this embodiment, the casing 3 is used to carry the winding core 2 and provide effective restraint and protection for the winding core 2 . The winding core 2 is placed in the casing 3 , and the end faces of the winding core 2 are provided with tab terminals, including positive tab terminals 21 and negative tab terminals 22 arranged on two opposite end faces.

The cover plate is matched with the end face of the winding core on which the tab terminals are arranged, the cover plate is provided with cell terminals, and the cell terminals are provided with terminal guide grooves for the tab terminals to penetrate. Please refer to FIG. 3 , in this embodiment, corresponding to the positive terminal 21 and the negative terminal 22 , the cover plate includes a positive terminal cover 5 and a negative terminal cover 4 , and the battery terminal provided on the positive terminal cover 5 is a positive terminal 11 (not shown in FIG. 2 and FIG. 3 ), the battery terminal set on the negative terminal cover plate 4 is the negative terminal 12 , the positive terminal 11 is provided with a positive terminal guide groove 51 for the positive terminal 21 to pass through, and the negative terminal 12 is provided with a negative terminal guide slot 41 for the negative terminal lug terminal 22 to pass through.

The structure of the positive terminal guide groove 51 is matched with the positive terminal 21 to guide the corresponding positive terminal 21 for connection. The structure of the negative terminal guide groove 41 is matched with the negative electrode lug terminal 22 to guide the negative electrode lug terminal 22 corresponding to the connection. After the positive terminal 21 and the negative terminal 22 penetrate into the positive terminal guide groove 51 and the negative terminal guide groove 41, the sealing between the cell terminal and the tab terminal can be ensured to a certain extent.

The cell terminals are hermetically connected to the tab terminals. In this embodiment, after the positive terminal cover 5 and the negative terminal cover 4 are assembled to the housing 3 , the positive terminal 21 penetrates into the positive terminal on the positive terminal 11 . The guide groove 51 and the negative terminal 22 penetrate into the negative terminal guide groove 41 on the negative terminal 21, and then the positive terminal 21 and the positive terminal 11, and the negative terminal 22 and the negative terminal 12 can be sealed and welded by means of laser welding, for example. , while ensuring effective electrical connection, it also ensures the sealing of the cell.

Further, an insulating material is integrated on a surface of the cover plate that matches the end surface of the winding core, and the terminal guide groove also penetrates the insulating material. In this embodiment, the insulating material is a plastic material. Specifically, still referring to FIG. 3 , the positive electrode cover plate 5 is integrated with the positive electrode cover plate plastic 52 on the side that matches the end face of the winding core provided with the positive electrode lug terminals 21 , and the positive electrode terminal guide groove 51 penetrates the positive electrode cover plate plastic 52 ; A negative electrode cover plate plastic 42 is integrated on the side of the extreme cover plate 4 that is matched with the end face of the winding core provided with the negative electrode ear terminal 22 , and the negative electrode terminal guide groove 41 penetrates through the negative electrode cover plate plastic 42 . The assembled negative cover plastic 42 and positive cover plastic 52 can support the two end faces of the winding core 2 , and play the role of insulation and fixed support for the winding core 2 to ensure the safety and stability of the winding core 2 during operation.

The plastic material can be polypropylene (PP) plastic, which can maintain good stability in the electrolyte, and at the same time, has good insulation and excellent injection molding performance. The plastic material can also use other insulating materials such as PET plastic, PFA plastic, etc. According to different materials, the structure needs to be adjusted to match the structure of the top cover and the battery core.

The function of the cover plate plastic has two points: one is insulation to ensure safety; the other is to fully support the end face of the core to achieve the purpose of fixing the core. Therefore, the matching part between the cover plate plastic and the end face of the winding core needs to be flat and must not protrude, otherwise the protruding part will squeeze the winding core excessively, causing a safety hazard.

Further, as shown in FIG. 3 , in this embodiment, a plurality of hollow structures 521 may be arranged on the insulating material (ie, the plastic of the cover) integrated on the cover plate. Increasing the hollow structure can reduce the weight of part of the plastic, and because the plastic itself It is made of injection molding, and there are many cavities inside. Adding a hollow structure can prevent the electrolyte from being trapped in the hollow cavities inside the battery after the battery is injected.

Embodiments of the present application further provide a lithium battery including the above-mentioned battery cell. Wherein, the winding core may be a winding structure or a lamination structure in structural form, and may be a single winding core or a parallel structure of multiple winding cores in terms of composition. A positive electrode lug terminal 21 and a negative electrode lug terminal 22 are respectively processed at both ends of the winding core 2. Through the structure design of the winding core, the current density distribution of the pole pieces inside the winding core can be effectively improved during the charging and discharging process. Part of the active material performance is more uniform, and the pre-processed positive terminal 21 and negative terminal 22 can be matched with the positive terminal guide groove 51 and the negative terminal guide groove 41 reserved on the positive terminal 11 and the negative terminal 12.

An embodiment of the present application also provides a method for manufacturing a battery cell, including: providing a winding core, with tab terminals disposed on an end surface of the winding core; inserting the winding core into a housing; providing a cover, the The cover plate is matched with the end face of the winding core that is provided with the tab terminals, the cover plate is provided with cell terminals, and the cell terminals are provided with terminal guide grooves for the tab terminals to penetrate; The cover plate is assembled to the casing in which the winding core is inserted, so that the tab terminals on the end face of the winding core are inserted into the terminal guide grooves on the battery core terminals.

Further, an insulating material is integrated on the surface of the cover plate that is matched with the end surface of the winding core, and when the cover plate is assembled to the casing with the winding core inserted, the insulating material is attached to the end surface of the winding core. combine.

Specifically, as shown in FIG. 2 , the corresponding ends of the winding core 2 are respectively provided with pre-processed positive terminal 21 and negative terminal 22, and the winding core 2 is inserted into the casing 3 according to the installation direction X shown in the figure; Then, as shown in Figure 3, assemble the negative end cover plate 4 according to the installation direction X1 shown in the figure, and assemble the positive end cover plate 5 according to the installation direction X2 shown in the figure. The negative end cover plate 4 and the positive end cover plate are assembled. 5 are respectively integrated with a negative electrode cover plate plastic 42 and a positive electrode cover plate plastic 52 .

The effect of the assembled battery cell 2 is shown in Figures 4A and 4B. After the negative terminal cover 4 and the positive terminal cover 5 are installed in place, the positive terminal 21 and the negative terminal 22 on the winding core 2 will penetrate into the positive terminal respectively. The positive terminal guide groove 51 and the negative terminal guide groove 41 provided on the cover plate 5 and the negative terminal cover plate 4, and finally the positive terminal 21 and the negative terminal 22 are respectively connected to the positive terminal 11 and the negative terminal by laser welding. 12 Welding is carried out to ensure the sealing of the cell while ensuring the effective electrical connection. The assembled negative cover plastic 42 and positive cover plastic 52 are respectively attached to the two end faces of the winding core 2, which can support the two end faces of the winding core 2, and play the role of insulating and supporting the winding core 2 to ensure the winding The core 2 is safe and stable during the working process.

It should be noted that, in the above embodiment, the tab terminal includes a positive tab terminal and a negative tab terminal, the two opposite end faces are the two end faces in the height direction of the winding core or the battery core, the positive tab terminal and the The negative lug terminals are arranged on different sides of the two opposite end faces in the height direction, that is, they are not concentrically offset from the two opposite end faces in the height direction. In practical applications, the positions of the tab terminals and the corresponding cell terminals are not limited to this, and can generally be adapted to the actual module solution. For example, the positive terminal and the negative terminal can be arranged in the height direction. The middle of the two opposite end faces of H, that is, the two opposite end faces in the height direction H, as shown in FIG. 5A, is the central tab terminal 6a in the height direction H; the positive tab terminal and the negative tab terminal can be set On the same side of the two opposite end faces in the height direction H, that is, concentrically offset from the two opposite end faces in the height direction H, as shown in FIG. 5B , the concentrically offset tab terminal 6b in the height direction H; the positive tab terminal And the negative electrode terminal can be arranged in the middle of the two opposite end faces in the width direction W, that is, placed in the middle of the two opposite end faces in the width direction W, as shown in FIG. 5C as the middle tab terminal 6c in the width direction W; The positive lug terminal and the negative lug terminal can be arranged on different sides of the two opposite end faces in the width direction W, that is, they are not eccentrically offset from the two opposite end faces in the width direction W, as shown in FIG. 5D . The tab terminal 6d is placed; the positive tab terminal and the negative tab terminal can be arranged on the same side of the two opposite end faces in the width direction W, that is, they are concentrically offset on the two opposite end faces in the width direction W, as shown in FIG. 5E . Concentrically offset tab terminal 6e in direction W.

In conclusion, after reading this detailed disclosure, those skilled in the art will appreciate that the foregoing detailed disclosure may be presented by way of example only, and may not be limiting. Although not explicitly described herein, it will be understood by those skilled in the art that this application is intended to cover various reasonable changes, improvements and modifications to the embodiments. Such changes, improvements and modifications are intended to be suggested by this disclosure and are within the spirit and scope of the exemplary embodiments of this disclosure.

Furthermore, certain terms in this application have been used to describe embodiments of the present disclosure. For example, "one embodiment," "an embodiment," and/or "some embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. Thus, it is emphasized and should be understood that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various parts of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as appropriate in one or more embodiments of the present disclosure.

It should be understood that, in the foregoing descriptions of embodiments of the present disclosure, in order to aid in the understanding of one feature, the application sometimes groups various features in a single embodiment, drawings, or description thereof for the purpose of simplifying the disclosure. Alternatively, the present application in turn disperses various features across multiple embodiments of the present application. However, this does not mean that the combination of these features is necessary, and it is entirely possible for those skilled in the art to extract some of the features as a separate embodiment to understand when reading this application. That is to say, the embodiments in this application can also be understood as the integration of multiple sub-embodiments. It is also true that each sub-embodiment contains less than all features of a single foregoing disclosed embodiment.

In some embodiments, numbers expressing quantities or properties used to describe and claim certain embodiments of the present application should be understood to be modified in certain instances by the terms "about," "approximately," or "substantially." For example, unless stated otherwise, "about", "approximately" or "substantially" may mean a ±20% variation of the value it describes. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, numerical parameters should be interpreted in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth broad ranges of the present application are approximations, the numerical values set forth in the specific examples are as precise as possible.

Each patent, patent application, publication of a patent application, and other materials, such as articles, books, specifications, publications, documents, articles, etc., cited herein, may be incorporated herein by reference. For all purposes in its entirety, except any filing history with which it relates, any identical filing that may be inconsistent or conflicting with this document, or any identical filing that may have a limiting effect on the broadest scope of the claims history. associated with this document now or in the future. For example, in the event of any inconsistency or conflict between the descriptions, definitions, and/or use of terms, descriptions, definitions, and/or terms associated with any of the included materials, use The term shall prevail.

Finally, it should be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of this application. Therefore, the embodiments disclosed in this application are merely illustrative and not limiting. Those skilled in the art may adopt alternative configurations according to the embodiments in the present application to implement the application in the present application. Accordingly, the embodiments of the present application are not limited to which embodiments are precisely described in the application.

Claims (7)

1. A battery cell, comprising:

a housing;

the winding core is arranged in the shell, and a tab terminal is arranged on the end face of the winding core;

the cover plate is matched with the end face, provided with the lug terminal, of the winding core, the cover plate is provided with the battery cell terminal, and the battery cell terminal is provided with a terminal guide groove for the lug terminal to penetrate into.

2. The battery cell of claim 1, wherein the mating surface of the cover sheet and the end surface of the winding core is integrated with an insulating material, and the terminal guide slot further extends through the insulating material.

3. The battery cell of claim 2, wherein the insulating material further comprises a plurality of hollowed-out structures.

4. The battery cell of claim 1, wherein at least two of the tab terminals are disposed on opposite end surfaces of the winding core.

5. The battery cell of claim 4, wherein the tab terminal comprises a positive tab terminal and a negative tab terminal, the two opposite end surfaces are two end surfaces in a height direction or a width direction of the winding core, and the positive tab terminal and the negative tab terminal are centrally or non-concentrically disposed on the two opposite end surfaces.

6. The battery cell of claim 1, wherein the cell terminal is sealingly connected with a tab terminal.

7. A lithium battery comprising the battery cell of any of claims 1 to 6.

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