Automatic liquid supplementing shell and lithium battery
The shrinking diaphragm in the automatic refill shell automatically opens the refill hole for refilling when the electrolyte in the battery cell cavity is consumed to a certain amount, solving the problems of abnormal filling and overflow of large-capacity battery cells and achieving efficient and safe electrolyte replenishment.
Patent Information
- Application Number
- CN202422300641.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-19
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-09-19
AI Technical Summary
During the filling process of large-capacity battery cells, the electrolyte is difficult to be absorbed by the core within a limited time, which can easily lead to abnormal filling and overflow.
An automatic refill shell is used, and a shrinkable diaphragm is used to automatically control the opening and closing of the refill hole based on the pressure difference between the battery cell cavity and the liquid storage cavity. When the electrolyte in the battery cell cavity is consumed to a certain amount, the shrinkable diaphragm made of pressure-sensitive material automatically opens the refill hole for refilling to avoid overflow.
It achieves a gradient fluid replenishment effect, improves the injection efficiency, avoids overflow and inability to inject fluid, and extends the cycle life of the battery cell.
Smart Images
Figure CN223333864U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium-ion batteries, in particular to an automatic liquid-replenishing shell and a lithium battery. Background Art
[0002] By the end of December 2023, China had a cumulative installed capacity of 34.5GW / 74.5GWh of new energy storage capacity in operation. This year, 21.5GW / 46.6GWh of new energy storage capacity was added, triple the amount added in 2022. Furthermore, the number of energy storage projects in 2023 exceeded 2,500, a year-on-year increase of 46%. The number of 100-megawatt projects in operation, planning, and construction in China continues to increase, as does the number of GWh energy storage projects. Against this backdrop, market demands for ever-increasing capacity in energy storage systems and batteries are rising. A surge in energy storage battery capacity, driven by larger capacity, has quietly begun. 300Ah+ batteries from various companies have entered the market. Energy storage batteries in various sizes, such as 305Ah, 314Ah, 320Ah, and 325Ah, are fueling a capacity race in 2023, accelerating the replacement of 280Ah batteries.
[0003] For large-capacity battery cells, as the size increases, the injection volume increases, and the electrolyte is difficult to be absorbed by the core within a limited time, and abnormal injection and overflow often occur. Utility Model Content
[0004] In order to overcome the defects in the prior art, the utility model provides an automatic liquid filling shell and a lithium battery. The automatic liquid filling shell can improve the liquid filling efficiency and avoid the problems of overflow and inability to fill liquid.
[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an automatic liquid replenishing shell, comprising:
[0006] A shell, wherein at least one side of the shell is provided with an opening, a separator is provided in the shell, and the separator is provided with a liquid replenishing hole, the separator divides the inner cavity of the shell into a battery cell cavity and a liquid storage cavity, the battery cell cavity is used to store the reaction electrolyte absorbed by the battery cell, and the liquid storage cavity is used to store the supplementary electrolyte;
[0007] A shrinkable diaphragm is provided in the fluid replenishing hole, and the shrinkable diaphragm expands or contracts based on a preset pressure difference of the electrolyte between the battery cell cavity and the liquid storage cavity to open or close the fluid replenishing hole.
[0008] As the reaction electrolyte in the cell cavity is consumed, a pressure difference is generated between the cell cavity and the liquid storage cavity, causing the contraction diaphragm to be subjected to pressure, wherein:
[0009] When the pressure applied to the contraction diaphragm is less than a threshold value, the contraction diaphragm is in a contracted state, sealing the fluid infusion hole;
[0010] When the pressure applied to the shrinkable diaphragm is greater than or equal to its threshold value, the shrinkable diaphragm stretches to open the liquid replenishing hole, and the replenished electrolyte in the liquid storage cavity enters the battery cell cavity through the liquid replenishing hole.
[0011] Through the above scheme, only when the reaction electrolyte in the battery cell cavity is consumed to a preset amount and the force on the shrink diaphragm reaches the threshold value, the shrink diaphragm will stretch to open the refill hole, so that the supplementary electrolyte in the liquid storage cavity enters the battery cell cavity from the refill hole to achieve refill, avoiding overflow caused by continuous refill.
[0012] Furthermore, the shrinkable diaphragm is made of a pressure-sensitive material, and the threshold for the shrinkable diaphragm to stretch under force is set to 3000 N. Through the above solution, the pressure in the cell cavity continues to decrease during the process of the battery cell absorbing the reactive electrolyte, and the pressure on the shrinkable diaphragm continues to increase. When the reactive electrolyte in the cell cavity is consumed to a certain amount, that is, when the force on the shrinkable diaphragm reaches 3000 N, the shrinkable diaphragm stretches, connecting the cell cavity and the rehydration cavity through the rehydration hole, and the replenishing electrolyte enters the cell cavity through the rehydration hole.
[0013] Furthermore, the separator is provided with a plurality of refill holes, each of which is provided with a contraction membrane, wherein the contraction membrane is configured to have at least two different thresholds. As the reactive electrolyte is consumed, the pressure within the cell cavity decreases, and the force on the contraction membrane increases. Providing multiple contraction membranes with different thresholds can achieve a gradient refill effect, with slow refilling for less use and fast refilling for more use.
[0014] Furthermore, the separator has a first end and a second end opposite to each other, and the threshold value of the contraction membrane increases from the first end to the second end of the separator.
[0015] Furthermore, the shell includes a bottom plate and side plates connected to the bottom plate, the partition includes at least three partition plates connected end to end, one end of the partition plate is connected to the bottom plate, the partition plate and the bottom plate enclose the battery cell cavity, and the liquid storage cavity is enclosed between the partition plate and the side plates.
[0016] Furthermore, the housing is provided with a refill port, which connects the liquid storage cavity with the outside, and a sealing plug is provided in the refill port. When the supplementary electrolyte is exhausted, the sealing plug can be pulled out and supplementary electrolyte can be added to the refill cavity through the refill port.
[0017] A battery comprises the above-mentioned automatic refill shell, a cover body arranged at the opening, and a battery cell arranged in the battery cell cavity, wherein the cover body is provided with an explosion-proof valve and a connecting column, and the electrode of the battery cell is connected to the connecting column.
[0018] Furthermore, the cover can seal the battery cell cavity and the liquid storage cavity at the same time. The cover is provided with a liquid filling port, which connects the liquid storage cavity with the outside world. A sealing plug is provided in the liquid filling port.
[0019] By means of the above technical solution, the beneficial effects of the present invention are as follows:
[0020] 1. In the present application, the cell cavity and the liquid storage cavity are separated by a partition provided with a liquid filling hole, and the liquid filling hole is sealed by a shrinkable diaphragm. The shrinkable diaphragm is made of a pressure-sensitive material. During the process of the battery cell absorbing the reaction electrolyte, the pressure in the cell cavity continues to decrease, and the pressure on the shrinkable diaphragm continues to increase. When the reaction electrolyte in the cell cavity is consumed to a certain amount, the pressure on the shrinkable diaphragm reaches a threshold value and expands, so that the cell cavity and the liquid filling cavity are connected through the liquid filling hole, and the replenishing electrolyte enters the cell cavity from the liquid filling hole;
[0021] 2. In this application, shrinkage diaphragms with multiple thresholds are provided. As the reaction electrolyte is consumed, the pressure in the battery cell cavity becomes smaller and smaller, and the force on the shrinkage diaphragm becomes larger and larger. By providing multiple shrinkage diaphragms with different thresholds, a gradient replenishment effect of less slow replenishment and more fast replenishment can be achieved.
[0022] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0024] Figure 1 This is a schematic structural diagram of the automatic liquid replenishment shell in an embodiment of the present utility model;
[0025] Figure 2 This is a schematic structural diagram of a partition plate in an embodiment of the present utility model;
[0026] Figure 3 It is a top cross-sectional view of the dynamic fluid infusion shell in an embodiment of the present utility model.
[0027] The reference numerals of the above drawings are: 1, side panel; 2, partition; 21, partition plate; 22, fluid infusion hole. DETAILED DESCRIPTION
[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0029] It should be noted that, in the description of this utility model, the terms "first," "second," etc., are used solely for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of this utility model, unless otherwise specified, "plurality" means two or more.
[0030] Example: Combination Figure 1-3 As shown, embodiment 1 discloses an automatic rehydration shell, comprising:
[0031] The housing includes a bottom plate and side plates 1 connected to the bottom plate. The bottom plate is rectangular, and four side plates 1 are vertically connected to the four sides of the rectangle. Any two adjacent side plates 1 are connected. The side of the side plate 1 facing away from the bottom plate forms the opening of the housing.
[0032] A separator 2 is connected to the housing. The separator 2 comprises four end-to-end partition plates 21, one end of which is fixedly connected to the bottom plate. The four partition plates 21 and the bottom plate define a cell cavity for accommodating cells and storing the reaction electrolyte. A rehydration cavity is located between the separator 2 and the side plate 1, which is used to store supplemental electrolyte.
[0033] The partition plate 21 is provided with a refill hole 22, and a plurality of the refill holes 22 are arranged in a matrix on the partition plate 21. A shrinkable diaphragm is provided at each refill hole, and the shrinkable diaphragm is made of a pressure-sensitive material. Initially, the shrinkable diaphragm is in a shrinking state, sealing the refill hole 22, thereby separating the battery cell cavity and the refill cavity. As the pressure in the battery cell cavity continues to decrease during the process of the battery cell absorbing the reaction electrolyte, the pressure on the shrinkable diaphragm continues to increase. When the reaction electrolyte in the battery cell cavity is consumed to a certain amount, the pressure on the shrinkable diaphragm reaches a threshold value and expands, so that the battery cell cavity and the refill cavity are connected through the refill hole, and the supplementary electrolyte in the liquid storage cavity enters the battery cell cavity from the refill hole 22 to complete the refill.
[0034] The pressure-sensitive material is polymethyl methacrylate, constructed by doping carbon nanofibers and carbon nanotubes. With this solution, only when the reactive electrolyte in the cell cavity is consumed to a preset amount will the contractile diaphragm be forced to expand, connecting the cell cavity and the refill cavity. This allows the replenishing electrolyte in the reservoir cavity to enter the cell cavity through the refill hole 22 to achieve refill, thus preventing overflow caused by continuous refill.
[0035] It should be noted that the threshold for the expansion of the shrinkable diaphragm under force can be controlled by adjusting the carbon nanotube concentration, and the carbon nanotube ratio is 1-3wt%. In this application, the threshold for the expansion of the shrinkable diaphragm under force is set to 3000N to ensure the liquid retention of the battery cell, which is conducive to improving the cycle life of the battery cell.
[0036] In another feasible embodiment, by adjusting the concentration of carbon nanotubes in each shrinkage diaphragm, shrinkage diaphragms with four different thresholds of 3000N, 5000N, 7000N, and 9000N are provided on the partition plate 21. When the reaction electrolyte in the battery cell cavity is consumed to the point where the shrinkage diaphragm is subjected to a force of 3000N, the shrinkage diaphragm with a threshold of 3000N is expanded. At this time, the liquid is only replenished through the refill holes of the expanded shrinkage diaphragm. If the refill rate is slower than the consumption rate of the reaction electrolyte in the battery cell cavity, the pressure in the battery cell cavity continues to decrease, and the force on the shrinkage diaphragm increases. When the force on the shrinkage diaphragm reaches 5000N, the shrinkage diaphragm with a threshold of 5000N is expanded. At this time, the shrinkage diaphragm with a threshold of 3000N remains expanded, and the replenishing electrolyte is replenished from the refill holes corresponding to the shrinkage diaphragms with thresholds of 3000N and 5000N. Until the contraction membrane is subjected to a force of 9000 N, all contraction membranes are fully opened for fluid infusion. The above solution achieves a gradient fluid infusion effect of less slow infusion and more fast infusion, improves fluid infusion efficiency, and further avoids the problems of overflow and inability to infuse fluid.
[0037] Embodiment 2 discloses a battery, comprising the above-mentioned automatic refill shell, a cover body arranged at the opening, and a battery cell arranged in the battery cell cavity, wherein the cover body is provided with an explosion-proof valve and a connecting column, and the electrode of the battery cell is connected to the connecting column.
[0038] The cover can simultaneously seal the battery cell cavity and the liquid storage cavity. The cover is provided with a liquid filling port, which connects the liquid storage cavity to the outside world. A sealing plug is provided within the liquid filling port. When the supplementary electrolyte is exhausted, the sealing plug can be removed and supplementary electrolyte can be added to the liquid filling cavity through the liquid filling port.
[0039] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. An automatic rehydration shell, characterized in that: include: A shell, wherein at least one side of the shell is provided with an opening, a separator is provided in the shell, and the separator is provided with a liquid replenishing hole, the separator divides the inner cavity of the shell into a battery cell cavity and a liquid storage cavity, the battery cell cavity is used to store the reaction electrolyte absorbed by the battery cell, and the liquid storage cavity is used to store the supplementary electrolyte; A shrinkable diaphragm is provided in the fluid replenishing hole, and the shrinkable diaphragm expands or contracts based on a preset pressure difference of the electrolyte between the battery cell cavity and the liquid storage cavity to open or close the fluid replenishing hole.
2. The automatic rehydration shell according to claim 1, characterized in that: The shrinkage diaphragm is made of a pressure-sensitive material, and the threshold value of the shrinkage diaphragm being stretched under force is set to 3000N.
3. The automatic rehydration shell according to claim 2, characterized in that: The partition is provided with a plurality of fluid infusion holes, each of the fluid infusion holes is provided with a contraction diaphragm, and the contraction diaphragm is configured to include at least two different thresholds.
4. The automatic rehydration shell according to claim 3, characterized in that: The separator has a first end and a second end opposite to each other, and the threshold value of the contraction membrane increases from the first end to the second end of the separator.
5. The automatic rehydration shell according to claim 1, characterized in that: The shell includes a bottom plate and side plates connected to the bottom plate. The partition includes at least three partition plates connected end to end. One end of the partition plate is connected to the bottom plate. The partition plate and the bottom plate enclose the battery cell cavity. The liquid storage cavity is enclosed between the partition plate and the side plates.
6. The automatic rehydration housing according to any one of claims 1, characterized in that: The shell is provided with a fluid infusion port, which connects the fluid storage cavity with the outside world, and a sealing plug is provided in the fluid infusion port.
7. A lithium battery, characterized in that: It comprises the automatic rehydration shell according to any one of claims 1 to 6, a cover body arranged at the opening, and a battery cell arranged in the battery cell cavity, the cover body is provided with an explosion-proof valve and a connecting column, and the electrode of the battery cell is connected to the connecting column.
8. The lithium battery according to claim 7, wherein The cover body can seal the battery cell cavity and the liquid storage cavity at the same time. The cover body is provided with a liquid filling port, which connects the liquid storage cavity with the outside world. A sealing plug is provided in the liquid filling port.