Lithium ion battery structure
By setting multiple cavity units and wall panel gaps in the lithium-ion battery housing, the problems of expansion deformation and safety risks of large-capacity batteries are solved, and higher energy density and safety performance are achieved.
Patent Information
- Application Number
- CN202323574538.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2033-12-22
AI Technical Summary
As the capacity of lithium-ion batteries increases, single cells are prone to expansion and deformation, resulting in an increase in safety risks.
A lithium-ion battery structure is designed, including a shell, a cover plate and a plurality of battery cell units. Multiple cavity units are arranged in the shell and a gap is set between the wall plate and the bottom surface and the top surface of the shell to increase the thickness direction of the shell. and make the bottoms between the cavity units interconnect to allow the electrolyte to flow, avoiding the problems of inconsistent liquid injection and uneven consumption of electrolyte.
It effectively improves the battery's ability to withstand expansion forces, reduces deformation risks, ensures the safety and energy density of the battery, and simplifies the preparation process and reduces costs.
Smart Images
Figure CN222233748U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and in particular relates to a lithium ion 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 new energy vehicles, drones, power tools, communication energy storage and other fields. With the growing prosperity of the energy storage market, energy storage battery products are developing towards large capacity, with the capacity of single cells developing from 50Ah~100Ah to 200Ah~350Ah, and then to 500Ah~600Ah, and there is even a trend towards larger capacity.
[0003] Large-capacity single cells can significantly increase the energy density of energy storage systems and are one of the important trends in the future development of the system. Compared with 50Ah to 100Ah single cells, large-capacity single cells have the following advantages: 1. Single cells have higher volume energy density, and fewer components are used at the pack end, which can significantly save costs; 2. Large-capacity single cells can use fewer batteries to achieve high-capacity battery products, reduce the number of parallel connections, and reduce the difficulty of BMS; 3. The application of large-capacity single cells can greatly simplify the integrated assembly process, which can significantly save the investment in land infrastructure, containers, etc., thereby further reducing costs.
[0004] However, as the capacity of single cells increases, the energy of single cells increases, and the size of single cells increases. The thickness of 200Ah~300Ah single cells is about 1.0~1.5 times that of 50Ah~100Ah, and the front area (length*width) of 200Ah~300Ah single cells is about 1.0~1.5 times that of 50Ah~100Ah. At the same time, the negative electrode graphite of lithium-ion batteries has a layered structure. During the battery charging and discharging process, lithium ions are embedded and removed between the graphite layers, resulting in a volume expansion change of about 10% in the graphite system. The greater the thickness and front area of the single cell, the greater the expansion stress on the center of the front of the single cell, the easier it is for the single cell to expand and deform, and the greater the safety risk of the battery. Utility Model Content
[0005] The present invention provides a lithium-ion battery structure, which aims to solve the problems of the traditional lithium battery single cell structure being prone to expansion and deformation and the high safety risk of the battery.
[0006] To achieve the above-mentioned purpose, the embodiment of the utility model provides a lithium-ion battery structure, comprising a shell, a cover plate and a plurality of battery cell units; the battery cell units are arranged in the shell, the cover plate is covered on the end surface of one end of the shell, and the battery cell units are connected to the cover plate;
[0007] The housing includes several cavity units, a wall plate is provided between adjacent cavity units, a first gap is provided between the wall plate and the bottom surface of the housing, and a second gap is provided between the wall plate and the top surface of the housing; the second gap is adapted to the cover plate; the battery cell unit is disposed in the cavity unit, and the battery cell unit and the cavity unit are arranged in one-to-one correspondence.
[0008] As a preferred embodiment, the depth of the first gap is the same as the depth of the second gap; the battery cell unit is adapted to the cavity unit.
[0009] As a preferred embodiment, several of the cavity units are arranged in parallel; the bottoms between adjacent cavity units are communicated with each other.
[0010] As a preferred embodiment, the thickness of the wall plate is 0.3 mm to 0.6 mm.
[0011] As a preferred embodiment, the wall plate and the housing are integrally formed; or, the wall plate is connected to the inner side surface of the housing by welding.
[0012] As a preferred embodiment, the housing includes two cavity units, and the two cavity units are arranged in parallel to form a double-cavity structure similar to the Chinese character '曰'.
[0013] As a preferred embodiment, the housing includes three cavity units, and the three cavity units are arranged in parallel to form a triple-cavity structure similar to the Chinese character '目'.
[0014] As a preferred embodiment, the wall plate is an aluminum wall plate, and the housing is an aluminum housing.
[0015] As a preferred embodiment, the cover plate includes a cover plate body, a positive pole column assembly and a negative pole column assembly; the positive pole column assembly and the negative pole column assembly are respectively disposed at both ends of the cover plate body, and the negative pole column assembly and the positive pole column assembly are respectively connected to the battery cell unit.
[0016] As a preferred embodiment, the negative pole column of the negative pole column assembly is connected to the negative pole tab of the battery cell unit, and the positive pole column of the positive pole column assembly is connected to the positive pole tab of the battery cell unit.
[0017] In the structure of the present application, multiple cavity units are arranged in the shell through the wall plate, and a first gap is set between the wall plate and the bottom surface of the shell, which effectively increases the strength of the shell in the thickness direction, so that the battery can withstand a greater expansion force without being easily deformed. At the same time, by setting the first gap, the bottoms of each cavity unit are interconnected, so that the electrolyte in each cavity unit can flow to each other, which can avoid the problem of battery cycle diving caused by inconsistent injection volume of each cavity unit during injection or different consumption of electrolyte in each cavity unit in the later stage of the single cell cycle. The present application has a simple structure, low preparation cost, small size, good sealing, high battery energy density, and high electrical energy stored per unit mass of the battery. It can be suitable for large-capacity and large-size battery structures. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] 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.
[0019] Figure 1 This is a schematic diagram of the exploded structure of a lithium-ion battery structure according to an embodiment of the utility model;
[0020] Figure 2 for Figure 1 A schematic structural diagram of a shell of a lithium-ion battery structure;
[0021] Figure 3 for Figure 2 A schematic diagram of a cross-sectional structure of a shell;
[0022] Figure 4 FIG. 1 is a schematic structural diagram of a shell of a square battery structure according to another embodiment. DETAILED DESCRIPTION
[0023] The technical solutions in the embodiments of the present utility model are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present utility model.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] Specifically, Figures 1 to 3 As shown, an embodiment of the present application provides a lithium-ion battery structure, comprising a housing 10, a cover plate 20 and a plurality of battery cells 30; the battery cells 30 are arranged in the housing 10, the cover plate 20 covers an end surface of one end of the housing 10, and the battery cells 30 are connected to the cover plate 20;
[0030] The shell 10 includes a plurality of cavity units 11, a wall panel 12 is arranged between adjacent cavity units 11, a first gap 40 is arranged between the wall panel 12 and the bottom surface of the shell 10, and a second gap 50 is arranged between the wall panel 12 and the top surface of the shell 10; the second gap 50 is adapted to be arranged with the cover plate 20; the battery cell unit 30 is arranged in the cavity unit 11, and the battery cell unit 30 and the cavity unit 11 are arranged one by one.
[0031] By setting a plurality of cavity units in the shell through the wall plate and controlling a first gap between the wall plate and the bottom surface of the shell, the strength of the shell 10 in the thickness direction is effectively increased, so that the battery can withstand a greater expansion force without being easily deformed, thereby increasing the safety of the battery.
[0032] As a preferred embodiment, the depth of the first gap 40 (i.e., the vertical distance between the wall panel 12 and the bottom surface of the shell) is the same as the depth of the second gap 50 (i.e., the vertical distance between the wall panel 12 and the top surface of the shell); the battery cell unit 30 is adaptively arranged with the cavity unit 11.
[0033] Generally, the depth of the first gap 40 is set to 2 mm to 5 mm, so that the shell 10 can have good strength in the thickness direction, and the electrolyte in each cavity unit 11 can fully flow with each other, thereby ensuring the consistency of the electrolyte in each cavity unit.
[0034] Usually, the depth of the second gap 50 is set to 3 mm to 6 mm, so that it can ensure that the shell 10 has good strength in the thickness direction and that the cover plate is compatible with the shell, thereby ensuring good sealing between the cover plate and the shell.
[0035] By setting the first gap 40 and controlling its depth, the bottoms of each cavity unit 11 are interconnected, so that the electrolyte in each cavity unit 11 can flow to each other, thereby avoiding the problem of battery cycle diving caused by inconsistent injection amounts of each cavity unit 11 during injection or different consumption of electrolyte in each cavity unit 11 in the late stage of the single cell cycle.
[0036] As a preferred embodiment, several cavity units 11 are arranged in parallel with each other; the bottoms of adjacent cavity units 11 are connected with each other. In this way, the electrolyte in each cavity unit 11 can flow to each other, which can avoid the problem of battery cycle diving caused by inconsistent injection amount of each cavity unit 11 during injection or different consumption of electrolyte in each cavity unit 11 in the later stage of single battery cycle.
[0037] As a preferred embodiment, the thickness of the wall panel 12 is 0.3 mm to 0.6 mm. According to actual usage requirements, the thickness of the wall panel 12 can be 0.3 mm, or 0.4 mm, or 0.5 mm, or 0.6 mm, etc. In this way, the strength of the housing in the thickness direction can be effectively increased, enabling the battery to withstand greater expansion force and not easily deform.
[0038] As a preferred embodiment, in the embodiment of the present application, the wall panel 12 and the housing 10 are integrally formed. It can be understood that in other embodiments, the wall panel 12 is connected to the inner side surface of the housing 10 by welding.
[0039] In this embodiment, the housing 10 includes two cavity units 11, and the two cavity units 11 are parallel to each other to form a double-cavity structure similar to the Chinese character '曰'. There are two battery cell units 30. In this way, the strength of the housing in the thickness direction can be effectively increased, enabling the battery to withstand greater expansion force and not easily deform, and increasing the safety of the battery.
[0040] It can be understood that as Figure 4 shown, in another embodiment, the housing 10 includes three cavity units 11, and the three cavity units 11 are parallel to each other to form a triple-cavity structure similar to the Chinese character '目'. In this way, the strength of the housing in the thickness direction can be effectively increased, enabling the battery to withstand greater expansion force and not easily deform, and increasing the safety of the battery.
[0041] As a preferred embodiment, the wall panel 12 is an aluminum wall panel, and the housing 10 is an aluminum housing. The aluminum wall panel and the aluminum housing have good heat conduction characteristics, and can conduct the heat generated inside the battery to the battery surface through the aluminum wall panel 12 between the cavity units 11, enhancing the heat dissipation effect of the battery and effectively increasing the safety performance of the battery.
[0042] As a preferred embodiment, the cover plate 20 includes a cover plate body 21, a positive terminal assembly 22, and a negative terminal assembly 23; the positive terminal assembly 22 and the negative terminal assembly 23 are respectively arranged at both ends of the cover plate body 21, and the negative terminal assembly 23 and the positive terminal assembly 22 are respectively connected to the battery cell unit 30.
[0043] As a preferred embodiment, the negative terminal of the negative terminal assembly 23 is connected to the negative tab of the battery cell unit 30, and the positive terminal of the positive terminal assembly 22 is connected to the positive tab of the battery cell unit 30.
[0044] In the structure of the present application, multiple cavity units are arranged in the shell through the wall plate, and a first gap is set between the wall plate and the bottom surface of the shell, which effectively increases the strength of the shell in the thickness direction, so that the battery can withstand a greater expansion force without being easily deformed. At the same time, by setting the first gap, the bottoms of each cavity unit are interconnected, so that the electrolyte in each cavity unit can flow to each other, which can avoid the problem of battery cycle diving caused by inconsistent injection volume of each cavity unit during injection or different consumption of electrolyte in each cavity unit in the later stage of the single cell cycle. The present application has a simple structure, low preparation cost, small size, good sealing, high battery energy density, and high electrical energy stored per unit mass of the battery. It can be suitable for large-capacity and large-size battery structures.
[0045] 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.
[0046] 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.
[0047] 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 lithium ion battery structure, characterized in that: It includes a housing, a cover plate, and several battery cell units; the battery cell units are arranged in the housing, the cover plate is covered on the end face of one end of the housing, and the battery cell units are connected to the cover plate. The housing includes several cavity units, a partition board is arranged between adjacent cavity units, a first gap is arranged between the partition board and the bottom surface of the housing, and a second gap is arranged between the partition board and the top surface of the housing; the second gap is adaptively arranged with the cover plate; the battery cell units are arranged in the cavity units, and the battery cell units are arranged in one-to-one correspondence with the cavity units.
2. The lithium-ion battery structure according to claim 1, characterized in that: The depth of the first gap is the same as the depth of the second gap; the battery cell units are adaptively arranged with the cavity units.
3. The lithium-ion battery structure according to claim 1, characterized in that: Several of the cavity units are arranged in parallel; the bottoms between adjacent cavity units are communicated with each other.
4. The lithium-ion battery structure according to claim 1, characterized in that: The thickness of the partition board is 0.3 mm to 0.6 mm.
5. The lithium-ion battery structure according to claim 1, characterized in that: The partition board is integrally formed with the housing; or, the partition board is connected to the inner side surface of the housing by welding.
6. The lithium-ion battery structure according to claim 1, characterized in that: The housing includes two cavity units, and the two cavity units are arranged in parallel to form a double-cavity structure similar to the Chinese character '曰'.
7. The lithium-ion battery structure according to claim 1, characterized in that: The housing includes three cavity units, and the three cavity units are arranged in parallel to form a triple-cavity structure similar to the Chinese character '目'.
8. The lithium-ion battery structure according to claim 1, characterized in that: The partition board is an aluminum partition board, and the housing is an aluminum housing.
9. The lithium-ion battery structure according to claim 1, characterized in that: The cover plate includes a cover plate body, a positive pole column assembly, and a negative pole column assembly; the positive pole column assembly and the negative pole column assembly are respectively arranged at both ends of the cover plate body, and the negative pole column assembly and the positive pole column assembly are respectively connected to the battery cell units.
10. The lithium-ion battery structure according to claim 9, characterized in that: The negative pole of the negative pole column assembly is connected to the negative pole tab of the battery cell unit, and the positive pole of the positive pole column assembly is connected to the positive pole tab of the battery cell unit.