Square battery structure
By adopting a square structure and a design that directly connects the tabs and poles in the lithium battery, combined with the method of covering the battery core with PP film, the problems of large volume and low energy density of the traditional lithium battery structure are solved, and higher energy is achieved. density and lower production costs.
Patent Information
- Application Number
- CN202323362228.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-08
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2033-12-08
AI Technical Summary
The traditional lithium battery structure uses a connecting piece to connect the electrode ears and the electrode columns, which requires welding process, resulting in large volume and low energy density, affecting the range of the electric vehicle.
It adopts a square battery structure and directly connects the positive lug to the positive pole and the negative lug to the negative pole to reduce the welding process, and uses PP film to cover the cell body, eliminating unnecessary space occupation and glueing process.
It effectively shortens the length of the internal structure of the battery, improves space utilization, increases the energy density of the battery, simplifies the production process, and reduces costs.
Smart Images
Figure CN222380810U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and in particular relates to a square battery structure. Background Art
[0002] Lithium-ion batteries have the advantages of long life, large specific capacity and no memory effect, and are widely used in electric vehicles and other fields. The driving range is the most intuitive performance indicator when buying an electric vehicle, and the driving range of an electric vehicle is closely related to the battery capacity; for the same electric vehicle product, the larger the battery capacity, the longer the driving range.
[0003] Battery energy density refers to the amount of electrical energy stored per unit mass of the battery. The greater the energy density, the more electrical energy is stored per unit mass of the battery. Generally speaking, increasing battery capacity is the key to solving the endurance problem. However, in fact, under the premise that the spatial layout cannot be changed and the curb weight is not increased, the core of battery technology upgrade is to increase battery energy density. At present, lithium batteries with traditional structures usually use connecting plates to connect the poles and poles, which requires welding processes to achieve. In addition, they are large in size, the battery energy density is low, and the electrical energy stored per unit mass of the battery is not high, which greatly affects the vehicle's range. Utility Model Content
[0004] The utility model provides a square battery structure, aiming to solve the problems of the traditional lithium battery structure using connecting pieces to connect the pole ears and poles, requiring welding process to achieve, large volume, low battery energy density, and low electrical energy stored per unit mass of the battery.
[0005] To achieve the above-mentioned purpose, the embodiment of the utility model provides a square battery structure, including a cover plate and at least one battery cell unit; the cover plate includes a cover plate body, a positive electrode column assembly and a negative electrode column assembly; the positive electrode column assembly and the negative electrode column assembly are respectively arranged at two ends of the cover plate body, and the negative electrode column assembly is connected to the battery cell unit;
[0006] The positive electrode column assembly includes a positive electrode upper plastic, a positive electrode column and a positive electrode sealing ring; the positive electrode column includes an integrally formed positive electrode column body and a positive electrode connecting portion, the positive electrode sealing ring is sleeved on the bottom end of the positive electrode column body, and the positive electrode sealing ring is abutted against the positive electrode connecting portion; the positive electrode upper plastic is sleeved on the upper end of the positive electrode column body, and the positive electrode upper plastic is respectively abutted against the positive electrode column body, the positive electrode connecting portion and the positive electrode sealing ring; the positive electrode connecting portion is connected to the battery cell unit.
[0007] As a preferred embodiment, the negative electrode column assembly includes a negative electrode upper plastic, a negative electrode column and a negative electrode sealing ring; the negative electrode column includes an integrally formed negative electrode column body and a negative electrode connecting portion, the negative electrode sealing ring is sleeved on the bottom end of the negative electrode column body, and the negative electrode sealing ring abuts against the negative electrode connecting portion; the negative electrode upper plastic is sleeved on the upper end of the negative electrode column body, and the negative electrode upper plastic abuts against the negative electrode column body, the negative electrode connecting portion and the negative electrode sealing ring respectively; the negative electrode connecting portion is connected to the battery cell unit.
[0008] As a preferred embodiment, a plurality of first strip grooves are circumferentially arranged on the inner side surface of the plastic on the positive electrode, and a plurality of first strip protrusions adapted to the first strip grooves are circumferentially arranged on the outer side surface of the positive electrode column body, the first strip protrusions are clamped in the first strip grooves, and the first strip protrusions are arranged one-to-one with the first strip grooves.
[0009] As a preferred embodiment, a plurality of second strip grooves are circumferentially arranged on the inner side surface of the plastic on the negative electrode, and a plurality of second strip protrusions adapted to the second strip grooves are circumferentially arranged on the outer side surface of the negative electrode column body, the second strip protrusions are clamped in the second strip grooves, and the second strip protrusions are arranged one-to-one with the second strip grooves.
[0010] As a preferred embodiment, the positive electrode column body is arranged at the geometric center of the positive electrode connecting portion; the negative electrode column body is arranged at the geometric center of the negative electrode connecting portion.
[0011] As a preferred embodiment, the battery cell unit includes a battery cell body, a positive electrode ear and a negative electrode ear, the positive electrode ear and the negative electrode ear are both arranged on the end face of one end of the battery cell body, and the positive electrode ear and the negative electrode ear are symmetrically arranged; the positive electrode ear is connected to the positive electrode connecting part, and the negative electrode ear is connected to the negative electrode connecting part.
[0012] As a preferred embodiment, the cover body includes a top cover sheet and a lower plastic, wherein the lower plastic abuts against the side of the top cover sheet close to the battery cell unit; the top cover sheet is provided with a first positive column hole and a first negative column hole, and the lower plastic is provided with a second positive column hole and a second negative column hole;
[0013] The positive electrode column body is arranged in the first positive electrode column hole after passing through the second positive electrode column hole, and the positive electrode connecting portion abuts against the side of the lower plastic close to the battery cell unit; the negative electrode column body is arranged in the first negative electrode column hole after passing through the second negative electrode column hole, and the negative electrode connecting portion abuts against the side of the lower plastic close to the battery cell unit.
[0014] As a preferred embodiment, a plurality of first square grooves are arranged circumferentially on the edge of the first positive electrode column hole; a plurality of first square protrusions adapted to the first square grooves are arranged on the side of the positive electrode plastic close to the top cover sheet, the first square protrusions are arranged in the first square grooves, and the first square protrusions and the first square grooves are arranged one-to-one.
[0015] As a preferred embodiment, a plurality of second square grooves are arranged circumferentially on the edge of the first negative electrode column hole; a plurality of second square protrusions adapted to the second square grooves are arranged on the side of the negative electrode upper plastic close to the top cover sheet, the second square protrusions are arranged in the second square grooves, and the second square protrusions and the second square grooves are arranged one-to-one.
[0016] As a preferred embodiment, an explosion-proof valve hole is provided at the geometric center of the top cover sheet, and the explosion-proof valve is provided in the explosion-proof valve hole; a vent hole is provided at the geometric center of the lower plastic, and the vent hole is provided below the explosion-proof valve hole.
[0017] As a preferred embodiment, the top cover sheet and one end of the lower plastic close to the positive electrode column body are both provided with a liquid injection hole.
[0018] As a preferred embodiment, the square battery structure further includes a PP film, the PP film is coated on the outer surface of the battery cell unit, and one end of the PP film is in contact with the side surface of the lower plastic close to the battery cell unit.
[0019] As a preferred embodiment, the square battery structure further includes a shell, which is disposed on the outside of the PP film, and the shell abuts against the side of the top cover sheet close to the battery cell unit.
[0020] As a preferred embodiment, the battery cell unit is a square wound battery cell or a square laminated battery cell; the square battery structure is a lithium ion battery structure or a sodium ion battery structure.
[0021] As a preferred embodiment, the positive electrode connecting portion is an aluminum plate connecting portion; and the negative electrode connecting portion is a copper-aluminum composite plate connecting portion.
[0022] The structure of the present application does not need to use positive and negative electrode connecting plates, and directly connects the positive ear to the positive pole column and the negative ear to the negative pole column. While reducing the welding process of the connecting plate, the length of the positive ear and the negative ear can be effectively shortened, so that the internal structure of the battery can be connected in an integrated manner, and the top space of the battery structure of the present application can be reduced to less than 7 mm; relative to the top space of the traditional battery structure of 15 mm, the structure of the present application can effectively increase the space utilization rate by more than 50% (more than 8 mm), thereby effectively improving the energy density of the battery structure. In addition, relative to the traditional process, the present application uses PP film to coat the battery body, which can eliminate the space occupied by the welding of the PP film and the cover plate, and at the same time eliminate the process of gluing the positive and negative poles, which can effectively prevent the electrochemical corrosion and leakage caused by the contact between the negative electrode and the aluminum shell. The present application has a simple structure, low preparation cost, small size, good sealing, high energy density of the battery, and high electrical energy stored per unit mass of the battery. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0024] Figure 1 This is a schematic structural diagram of a square battery structure of an embodiment of the utility model;
[0025] Figure 2 for Figure 1 Schematic diagram of the exploded structure of a square battery structure;
[0026] Figure 3 for Figure 2 Schematic diagram of the explosion structure of the cover plate;
[0027] Figure 4 for Figure 1 Schematic diagram of the structure of a cell unit with a square battery structure. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the utility model are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0029] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, top, bottom...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0030] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.
[0032] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.
[0033] In the square battery structure of the embodiment of the present application, the number of battery cell units can be set according to actual use needs, and can be set to one, two, three, four or even more.
[0034] Specifically, in this embodiment, a square battery structure provided with two battery cell units is taken as an example to explain the square battery structure in detail.
[0035] like Figures 1 to 4As shown, the embodiment of the present application provides a square battery structure, including a cover plate 10 and at least one battery cell unit 20; the cover plate 10 includes a cover plate body 11, a positive electrode column assembly 12 and a negative electrode column assembly 13; the positive electrode column assembly 12 and the negative electrode column assembly 13 are respectively arranged at both ends of the cover plate body 11, and the negative electrode column assembly 13 is connected to the battery cell unit 20;
[0036] The positive electrode column assembly 12 includes a positive electrode upper plastic 121, a positive electrode column 122 and a positive electrode sealing ring 123; the positive electrode column 122 includes an integrally formed positive electrode column body 1221 and a positive electrode connecting portion 1222, the positive electrode sealing ring 123 is sleeved on the bottom end of the positive electrode column body 1221, and the positive electrode sealing ring 123 is abutted against the positive electrode connecting portion 1222; the positive electrode upper plastic 121 is sleeved on the upper end of the positive electrode column body 1221, and the positive electrode upper plastic 121 is respectively abutted against the positive electrode column body 1221, the positive electrode connecting portion 1222, and the positive electrode sealing ring 123; the positive electrode connecting portion 1222 is connected to the battery cell unit 20.
[0037] As a preferred embodiment, the negative electrode column assembly 13 includes a negative electrode upper plastic 131, a negative electrode column 132 and a negative electrode sealing ring 133; the negative electrode column 132 includes an integrally formed negative electrode column body 1321 and a negative electrode connecting portion 1322, the negative electrode sealing ring 133 is sleeved on the bottom end of the negative electrode column body 1321, and the negative electrode sealing ring 133 is abutted against the negative electrode connecting portion 1322; the negative electrode upper plastic 131 is sleeved on the upper end of the negative electrode column body 1321, and the negative electrode upper plastic 131 is respectively abutted against the negative electrode column body 1321, the negative electrode connecting portion 1322, and the negative electrode sealing ring 133; the negative electrode connecting portion 1322 is connected to the battery cell unit 20.
[0038] As a preferred embodiment, a plurality of first strip grooves 1211 are circumferentially arranged on the inner side of the positive electrode upper plastic 121, and a plurality of first strip protrusions (not marked in the figure) adapted to the first strip grooves 1211 are circumferentially arranged on the outer side of the positive electrode column body 1221, and the first strip protrusions are clamped in the first strip grooves 1211, and the first strip protrusions are arranged one-to-one with the first strip grooves 1211. In this way, the sealing between the positive electrode upper plastic 121 and the positive electrode column can be better ensured.
[0039] As a preferred embodiment, a plurality of second strip grooves 1311 are circumferentially arranged on the inner side of the negative electrode upper plastic 131, and a plurality of second strip protrusions (not marked in the figure) matching the second strip grooves 1311 are circumferentially arranged on the outer side of the negative electrode column body 1321, and the second strip protrusions are clamped in the second strip grooves 1311, and the second strip protrusions are arranged one-to-one with the second strip grooves 1311. In this way, the sealing between the negative electrode upper plastic 131 and the negative electrode column can be better ensured.
[0040] As a preferred embodiment, the positive electrode column body 1221 is disposed at the geometric center of the positive electrode connecting portion 1222 ; the negative electrode column body 1321 is disposed at the geometric center of the negative electrode connecting portion 1322 .
[0041] As a preferred embodiment, the battery cell unit 20 includes a battery cell body 21, a positive electrode ear 22 and a negative electrode ear 23, the positive electrode ear 22 and the negative electrode ear 23 are both arranged on the end face of one end of the battery cell body 21, and the positive electrode ear 22 and the negative electrode ear 23 are symmetrically arranged; the positive electrode ear 22 is connected to the positive electrode connecting portion 1222, and the negative electrode ear 23 is connected to the negative electrode connecting portion 1322.
[0042] As a preferred embodiment, the cover body 11 includes a top cover sheet 111 and a lower plastic 112, wherein the lower plastic 112 abuts against the side of the top cover sheet 111 close to the battery cell unit 20; the top cover sheet 111 is provided with a first positive electrode column hole A and a first negative electrode column hole B, and the lower plastic 112 is provided with a second positive electrode column hole C and a second negative electrode column hole D;
[0043] The positive electrode column body 1221 is disposed in the first positive electrode column hole A after passing through the second positive electrode column hole C, and the positive electrode connecting portion 1222 abuts against the side of the lower plastic 112 close to the battery cell unit 20; the negative electrode column body 1321 is disposed in the first negative electrode column hole B after passing through the second negative electrode column hole D, and the negative electrode connecting portion 1322 abuts against the side of the lower plastic 112 close to the battery cell unit 20.
[0044] As a preferred embodiment, a plurality of first square grooves A1 are arranged around the edge of the first positive electrode column hole A; a plurality of first square protrusions (not marked in the figure) matching the first square grooves A1 are arranged on the side of the positive electrode upper plastic 121 close to the top cover sheet 111, and the first square protrusions are arranged in the first square grooves A1, and the first square protrusions are arranged in a one-to-one correspondence with the first square grooves A1. By arranging the first square grooves and the first square protrusions, the sealing between the positive electrode column and the top cover sheet can be better ensured.
[0045] As a preferred embodiment, a plurality of second square grooves B1 are arranged around the edge of the first negative electrode column hole B; a plurality of second square protrusions (not marked in the figure) matching the second square grooves B1 are arranged on the side of the negative electrode upper plastic 131 close to the top cover sheet 111, and the second square protrusions are arranged in the second square grooves B1, and the second square protrusions are arranged one by one with the second square grooves B1. By arranging the second square grooves and the second square protrusions, the sealing between the negative electrode column and the top cover sheet can be better ensured.
[0046] As a preferred embodiment, an explosion-proof valve hole E is provided at the geometric center of the top cover sheet 111, and the explosion-proof valve 30 is provided in the explosion-proof valve hole E; a vent hole F is provided at the geometric center of the lower plastic 112, and the vent hole F is provided below the explosion-proof valve hole E.
[0047] As a preferred embodiment, the top cover sheet 111 and the lower plastic 112 are both provided with a liquid injection hole G at one end close to the positive electrode column body 1221 .
[0048] As a preferred embodiment, the square battery structure further includes a PP film 40 , which is coated on the outer surface of the battery cell unit 20 , and one end of the PP film 40 abuts against the side surface of the lower plastic 112 close to the battery cell unit 20 .
[0049] As a preferred embodiment, the square battery structure further includes a shell 50 , which is disposed on the outside of the PP film 40 , and the shell 50 abuts against the side of the top cover sheet 111 close to the battery cell unit 20 .
[0050] As a preferred embodiment, the battery cell unit 20 is a square wound battery cell or a square laminated battery cell; the square battery structure is a lithium ion battery structure or a sodium ion battery structure.
[0051] As a preferred embodiment, the positive electrode connection portion 1222 is an aluminum plate connection portion; and the negative electrode connection portion 1322 is a copper-aluminum composite plate connection portion.
[0052] The structure of the present application does not need to use positive and negative electrode connecting plates, and directly connects the positive ear to the positive pole column and the negative ear to the negative pole column. While reducing the welding process of the connecting plate, the length of the positive ear and the negative ear can be effectively shortened, so that the internal structure of the battery can be connected in an integrated manner, and the top space of the battery structure of the present application can be reduced to less than 7 mm; relative to the top space of 15 mm of the traditional battery structure, the structure of the present application can effectively increase the space utilization rate by more than 50% (more than 8 mm), thereby effectively improving the energy density of the battery structure. In addition, relative to the traditional process, the present application uses PP film to coat the battery body, which can eliminate the space occupied by the PP film and the cover plate welding, and at the same time eliminate the process of gluing the positive and negative poles, which can effectively prevent the electrochemical corrosion and leakage caused by the contact between the negative electrode and the aluminum shell. The present application has a simple structure, low preparation cost, small volume, high energy density of the battery, and high electrical energy stored per unit mass of the battery.
[0053] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.
[0054] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A square battery structure, characterized in that: It includes a cover plate and at least one battery cell unit; the cover plate includes a cover plate body, a positive electrode column assembly and a negative electrode column assembly; the positive electrode column assembly and the negative electrode column assembly are respectively arranged at two ends of the cover plate body, and the negative electrode column assembly is connected to the battery cell unit; The positive electrode column assembly includes a positive electrode upper plastic, a positive electrode column and a positive electrode sealing ring; the positive electrode column includes an integrally formed positive electrode column body and a positive electrode connecting portion, the positive electrode sealing ring is sleeved on the bottom end of the positive electrode column body, and the positive electrode sealing ring is abutted against the positive electrode connecting portion; the positive electrode upper plastic is sleeved on the upper end of the positive electrode column body, and the positive electrode upper plastic is respectively abutted against the positive electrode column body, the positive electrode connecting portion and the positive electrode sealing ring; the positive electrode connecting portion is connected to the battery cell unit.
2. The square battery structure according to claim 1, characterized in that: The negative electrode column assembly includes a negative electrode upper plastic, a negative electrode column and a negative electrode sealing ring; the negative electrode column includes an integrally formed negative electrode column body and a negative electrode connecting portion, the negative electrode sealing ring is sleeved on the bottom end of the negative electrode column body, and the negative electrode sealing ring is in contact with the negative electrode connecting portion; the negative electrode upper plastic is sleeved on the upper end of the negative electrode column body, and the negative electrode upper plastic is respectively in contact with the negative electrode column body, the negative electrode connecting portion and the negative electrode sealing ring; the negative electrode connecting portion is connected to the battery cell unit.
3. The square battery structure according to claim 2, characterized in that: A plurality of first strip grooves are circumferentially arranged on the inner side surface of the plastic on the positive electrode, and a plurality of first strip protrusions adapted to the first strip grooves are circumferentially arranged on the outer side surface of the positive electrode column body, the first strip protrusions are clamped in the first strip grooves, and the first strip protrusions are arranged one-to-one with the first strip grooves; A plurality of second strip grooves are circumferentially arranged on the inner side surface of the plastic on the negative electrode, and a plurality of second strip protrusions adapted to the second strip grooves are circumferentially arranged on the outer side surface of the negative electrode column body, the second strip protrusions are clamped in the second strip grooves, and the second strip protrusions are arranged one-to-one with the second strip grooves; The positive electrode column body is arranged at the geometric center of the positive electrode connecting portion; the negative electrode column body is arranged at the geometric center of the negative electrode connecting portion.
4. The square battery structure according to claim 3, characterized in that: The battery cell unit includes a battery cell body, a positive electrode ear and a negative electrode ear. The positive electrode ear and the negative electrode ear are both arranged on the end surface of one end of the battery cell body. The positive electrode ear and the negative electrode ear are symmetrically arranged; the positive electrode ear is connected to the positive electrode connecting part, and the negative electrode ear is connected to the negative electrode connecting part.
5. The square battery structure according to claim 4, characterized in that: The cover body includes a top cover sheet and a lower plastic, wherein the lower plastic abuts against the side of the top cover sheet close to the battery cell unit; the top cover sheet is provided with a first positive column hole and a first negative column hole, and the lower plastic is provided with a second positive column hole and a second negative column hole; The positive electrode column body is arranged in the first positive electrode column hole after passing through the second positive electrode column hole, and the positive electrode connecting portion abuts against the side of the lower plastic close to the battery cell unit; the negative electrode column body is arranged in the first negative electrode column hole after passing through the second negative electrode column hole, and the negative electrode connecting portion abuts against the side of the lower plastic close to the battery cell unit.
6. The square battery structure according to claim 5, characterized in that: A plurality of first square grooves are arranged in the circumferential direction of the edge of the first positive electrode column hole; a plurality of first square protrusions matching the first square grooves are arranged on the side of the positive electrode upper plastic close to the top cover sheet, the first square protrusions are arranged in the first square grooves, and the first square protrusions and the first square grooves are arranged one by one; A plurality of second square grooves are arranged circumferentially on the edge of the first negative electrode column hole; a plurality of second square protrusions adapted to the second square grooves are arranged on the side of the negative electrode upper plastic close to the top cover sheet, the second square protrusions are arranged in the second square grooves, and the second square protrusions and the second square grooves are arranged one-to-one.
7. The square battery structure according to claim 6, characterized in that: An explosion-proof valve hole is provided at the geometric center of the top cover sheet, and the explosion-proof valve is provided in the explosion-proof valve hole; a vent hole is provided at the geometric center of the lower plastic, and the vent hole is provided below the explosion-proof valve hole; The top cover sheet and one end of the lower plastic close to the positive pole body are both provided with a liquid injection hole.
8. The square battery structure according to claim 7, characterized in that: The square battery structure further includes a PP film, which is coated on the outer surface of the battery cell unit, and one end of the PP film is in contact with the side surface of the lower plastic close to the battery cell unit.
9. The square battery structure according to claim 8, characterized in that: The square battery structure further includes a shell, which is disposed on the outside of the PP film, and the shell abuts against the side surface of the top cover sheet close to the battery cell unit.
10. The square battery structure according to claim 9, characterized in that: The battery cell unit is a square wound battery cell or a square laminated battery cell; the square battery structure is a lithium ion battery structure or a sodium ion battery structure.