A tightly packed battery structure

Abstract

The utility model relates to a kind of tight assembly battery structure, comprising: shell;And battery pole group and elastic block installed in shell, the elastic block is spaced apart between battery pole group and shell and is in pre-compression state, when the internal pressure of the battery pole group reduces, the elastic block releases pressure and maintains the internal pressure of the battery pole group.The utility model is by setting pre-compression elastic block between battery pole group and shell, the elastic potential energy released by elastic block is continuously applied to pole group with pressure, maintains the stable pressure in pole group, this design can effectively alleviate the expansion and shedding of positive active material in battery charge-discharge cycle, avoid the capacity attenuation caused by active material loss;Meanwhile, the stable internal pressure of pole group can keep AGM separator and pole plate closely adhere, ensure ion conduction efficiency, compared with traditional structure can significantly prolong battery service life by more than 30%, and long-term maintain stable discharge performance.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and specifically relates to a tightly assembled battery structure. Background Technology

[0002] The internal electrode group of a lead-acid battery consists of a stacked positive electrode plate, separator, and negative electrode plate. For maintenance-free batteries, a tight-fitting design is used, and the separator is typically made of AGM (ultra-fine glass fiber). Especially in lead-acid batteries, the positive electrode active material gradually expands during charge-discharge cycles, eventually leading to a decrease in the conductivity of the void structure and continuous shedding of active material, resulting in a gradual decline in battery capacity and lifespan. Therefore, for lead-acid batteries, maintaining internal pressure within the electrode group helps mitigate the shedding of active material during battery use, thereby improving product lifespan. For batteries using AGM separators, the separator compression reaches 20%-30% during assembly, and the electrode group pressure reaches 50-60 kPa. The AGM separator is composed of ultra-fine glass fiber. Glass fiber itself is incompressible; the stacking method of the glass fibers creates gaps and compressibility between them. The separator compression process involves the rotation, stretching, and even aggregation of the fibers.

[0003] AGM separators have excellent elasticity in the dry state, which can provide a certain internal pressure for the electrode group. However, when the AGM separator is wetted, it is easier to compress than when it is dry, and its elasticity is significantly reduced.

[0004] When the electrode group is installed into the battery casing, the internal pressure of the electrode group is relatively high. However, after the battery is filled with acid, the AGM is completely wetted by the liquid, and the compressive elasticity of the AGM separator is significantly reduced, causing the internal pressure of the electrode group to drop rapidly by more than 90%.

[0005] Furthermore, during the operation of valve-regulated batteries, some moisture is lost to the outside air through the safety valve. However, since valve-regulated batteries are designed to be maintenance-free, this lost moisture cannot be directly replenished. This continuous loss can lead to capacity decay, thermal runaway, and grid corrosion, among other problems. This is the most common failure mode for valve-regulated batteries. How to replenish the trace amounts of moisture lost during the use of valve-regulated batteries is a challenge for improving battery life.

[0006] Therefore, it is necessary to address the issue of decreased electrode assembly pressure after the AGM separator is wetted. Utility Model Content

[0007] This utility model addresses the problems of existing technologies by providing a tightly assembled battery structure, the specific technical solution of which is as follows: A tightly assembled battery structure, comprising: case; The battery electrode group and elastic block are installed inside the housing. The elastic block is spaced between the battery electrode group and the housing and is in a pre-compressed state. When the internal pressure of the battery electrode group decreases, the elastic block releases the pressure and maintains the internal pressure of the battery electrode group.

[0008] As a further technical solution of this utility model, the elastic block includes a support plate covering the surface of the battery electrode group and a support foot inclinedly disposed between the support plate and the housing.

[0009] As a further technical solution of this utility model, the support feet are arranged in several groups along the battery trajectory, and adjacent support feet are arranged symmetrically.

[0010] As a further technical solution of this utility model, the support plate is supported by the support feet and can cooperate with the shell to form a storage cavity. The storage cavity is pre-filled with an electrolyte replenishment block. The support plate has a replenishment hole. When the battery electrode group loses water, the water in the electrolyte replenishment block can be replenished to the battery electrode group through the replenishment hole.

[0011] As a further technical solution of this utility model, the electrolyte replenishment block is a colloid made of sulfuric acid and silica sol.

[0012] The beneficial effects of this utility model are as follows: Addressing the core issues of traditional AGM separator batteries, such as "separator wetting, reduced elasticity, and a sharp drop in internal pressure of over 90% after acid addition," this solution incorporates a pre-compressed elastic block between the battery electrode group and the casing. The elastic potential energy released by this block continuously applies pressure to the electrode group, maintaining stable internal pressure. This design effectively mitigates the expansion and shedding of the positive electrode active material during charge-discharge cycles, preventing capacity decay caused by active material loss. Simultaneously, the stable internal pressure of the electrode group ensures a tight fit between the AGM separator and the electrode plates, guaranteeing ion conduction efficiency. Compared to traditional structures, this significantly extends battery life by over 30% and maintains stable discharge performance over the long term.

[0013] The structural design of the elastic block, consisting of a support plate and tilted symmetrical support feet, enables uniform pressure transmission and adaptive adjustment: the support plate covering the electrode group surface can fit the electrode group over a large area, avoiding local pressure concentration that could lead to electrode plate deformation; multiple sets of symmetrical tilted support feet arranged along the battery trajectory can evenly distribute the support force along the electrode group axis, preventing electrode group displacement and warping; at the same time, the tilted support feet increase the range of elastic deformation through angle changes, so when the electrode group undergoes slight deformation due to temperature changes or slight expansion of active materials, the support feet can adaptively deform to maintain pressure stability, rather than rigidly resisting it, thus protecting the overall structural integrity of the electrode group while ensuring constant pressure.

[0014] This design constructs an active water replenishment system by using a reservoir cavity formed by a support plate and the casing, a pre-filled electrolyte replenishment block, and replenishment holes on the support plate. When the AGM separator's humidity decreases due to moisture loss from the battery electrode group via the safety valve, the humidity difference between the electrolyte replenishment block and the electrode group in the reservoir cavity drives moisture to slowly permeate through the replenishment holes into the AGM separator, replenishing the lost moisture to maintain the stability of electrolyte concentration and total volume. This design overcomes the limitation of traditional valve-regulated batteries being "maintenance-free but unable to replenish water," fundamentally solving the problems of capacity decay, thermal runaway, and grid corrosion caused by moisture loss. Furthermore, the precise design of the replenishment hole diameter matches the water loss rate of the electrode group, preventing electrolyte overflow or insufficient replenishment, and achieving safe and continuous water replenishment without manual intervention. Attached Figure Description

[0015] Figure 1 A front sectional view of a tightly assembled battery structure is shown; Figure 2 A side sectional view of a tightly assembled battery structure is shown; Figure 3 A top sectional view of a tightly assembled battery structure is shown.

[0016] Legend: 1. Battery electrode group; 2. Elastic block; 3. Electrolyte replenishment block. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0018] Figure 1 A front sectional view of a tightly assembled battery structure is shown; Figure 2 A side sectional view of a tightly assembled battery structure is shown; Figure 3 A top sectional view of a tightly assembled battery structure is shown. Figures 1-3 The present invention relates to a tightly assembled battery structure, comprising: a housing; and a battery electrode group 1 and an elastic block 2 installed inside the housing. The elastic block 2 is spaced between the battery electrode group 1 and the housing and is in a pre-compressed state. When the internal pressure of the battery electrode group 1 decreases, the elastic block 2 releases the pressure and maintains the internal pressure of the battery electrode group 1.

[0019] The core problem of existing AGM separator batteries is that "after adding acid, the separator becomes wetted, its elasticity is significantly reduced, and the internal pressure of the electrode group drops sharply by more than 90%". This structure fundamentally overcomes this defect by setting a pre-compressed elastic block 2 between the battery electrode group 1 and the casing. During assembly, the elastic block 2 is first compressed to a preset deformation state to store elastic potential energy. When the elasticity of the AGM separator decreases after adding acid and the internal pressure of the electrode group begins to drop, the elastic block 2 releases the stored elastic potential energy and generates an outward supporting force through its own elastic deformation, simultaneously supporting the casing and applying force to the battery electrode group 1. Continuous pressure maintains stable internal pressure within the electrode group, preventing significant internal pressure loss. This design directly addresses the industry pain point of a sudden drop in internal pressure after the AGM separator becomes wetted. Through the continuous pressure support of the elastic block, it effectively mitigates the expansion and shedding of the positive electrode active material during battery charge and discharge cycles, preventing capacity decay and shortened lifespan due to active material loss. Simultaneously, the stable internal pressure of the electrode group maintains a tight fit between the AGM separator and the electrode plates, ensuring ion conduction efficiency and further maintaining the battery's long-term discharge performance. Compared to traditional structures, this design can significantly extend battery lifespan by more than 30%.

[0020] It should be noted that the elastic block is made of acid-resistant plastic.

[0021] Batteries are filled with sulfuric acid electrolyte and are exposed to a highly acidic corrosive environment for extended periods. If ordinary plastic is used for the elastic block, it will be gradually decomposed and aged by the sulfuric acid, leading to structural damage or loss of elasticity, and making it unable to maintain internal pressure in the long term. In contrast, acid-resistant plastics, such as modified polytetrafluoroethylene (PTFE) and acid-resistant nylon, have excellent resistance to sulfuric acid corrosion. Their molecular structure is stable and they will not react chemically with sulfuric acid, nor will they swell or become embrittled due to electrolyte wetting. They can maintain their intact structure and stable elasticity throughout the entire battery life.

[0022] See Figure 3 The elastic block 2 includes a support plate covering the surface of the battery electrode group 1 and support feet inclined between the support plate and the housing. Several sets of support feet are arranged along the battery trajectory, and adjacent support feet are symmetrically arranged.

[0023] The "support plate and tilted symmetrical support feet" structure of the elastic block 2 is key to achieving "uniform force transmission and stable rebound". The support plate adopts a shape adapted to the surface of the battery electrode group 1, which can make large-area and uniform contact with the electrode group surface, avoiding local pressure concentration that could lead to electrode plate deformation. The support feet are tilted rather than vertical, which can increase the range of elastic deformation by changing the tilt angle. At the same time, multiple sets of symmetrical support feet are set along the battery trajectory, such as the length of the electrode group, so that the support force can be evenly distributed along the axis of the electrode group, preventing the electrode group from shifting or warping due to uneven force, and ensuring the overall structural stability of the electrode group. Through the large-area contact of the support plate and the symmetrical distribution of the support feet, the support force of the elastic block is evenly transmitted to the entire surface of the electrode group, avoiding local damage to the electrode plate. The elastic advantage of the tilted support feet further enhances the flexibility of internal pressure regulation. When the electrode group undergoes slight deformation due to temperature changes or slight expansion of active materials, the support feet can maintain pressure stability through adaptive deformation, rather than rigid resistance, thus protecting the electrode group and ensuring constant pressure.

[0024] See Figure 3 The support plate, supported by the support feet, can cooperate with the shell to form a storage cavity. The storage cavity is pre-filled with electrolyte replenishment block 3. The support plate has a replenishment hole. When the battery electrode group 1 loses water, the water in the electrolyte replenishment block 3 can be replenished to the battery electrode group 1 through the replenishment hole.

[0025] A common failure mode of valve-regulated batteries is "moisture loss through the safety valve, leading to electrolyte desiccation due to lack of replenishment." This structure forms an active water replenishment system through the design of a "reservoir chamber, electrolyte replenishment block 3, and replenishment hole." The reservoir chamber, enclosed by the support plate and the casing, serves as a storage space for the water replenishment material. The pre-filled electrolyte replenishment block 3 contains slowly released moisture. When the humidity of the AGM separator decreases due to moisture loss from the battery electrode group 1, a humidity difference will form between the replenishment block 3 and the electrode group within the reservoir chamber. Under osmotic pressure, the moisture in the replenishment block will slowly seep through the replenishment hole on the support plate. The water permeates into the AGM separator, replenishing lost moisture and maintaining the stability of electrolyte concentration and total volume. This design overcomes the limitation of traditional valve-regulated batteries that are "maintenance-free but cannot be replenished with water," fundamentally solving the problems of capacity decay, thermal runaway, and grid corrosion caused by water loss. It allows the battery to maintain electrolyte stability without manual water replenishment during long-term use. At the same time, the pore size of the replenishment hole is precisely designed to control the water replenishment rate to match the electrode group water loss rate, avoiding excessive water replenishment at one time that could lead to electrolyte overflow, or insufficient water replenishment that could not alleviate dryness, ensuring a safe and continuous water replenishment process.

[0026] Electrolyte replenishment block 3 is a colloid made of sulfuric acid and silica sol.

[0027] Electrolyte replenishment block 3 uses a colloidal form of "sulfuric acid and silica sol," a core design that balances "component compatibility" and "stable storage." The sulfuric acid content is consistent with the acid concentration of the original electrolyte in the battery, so adding water will not change the overall acid concentration of the electrolyte, avoiding the impact of acid concentration fluctuations on the battery's electrochemical reaction. As a colloidal matrix, silica sol can stably encapsulate sulfuric acid and water to form a gel-like solid. This not only prevents uneven concentration caused by the replenishment block shaking inside the battery, but also allows for continuous and uniform release of water through the slow permeation characteristics of the colloid, rather than rapid loss.

[0028] The above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit it.

Claims

1. A tightly assembled battery structure, characterized in that, include: case; The battery electrode group (1) and elastic block (2) are installed in the housing. The elastic block (2) is spaced between the battery electrode group (1) and the housing and is in a pre-compressed state. When the internal pressure of the battery electrode group (1) decreases, the elastic block (2) releases the pressure and maintains the internal pressure of the battery electrode group (1).

2. The tightly assembled battery structure according to claim 1, characterized in that: The elastic block (2) includes a support plate covering the surface of the battery electrode group (1) and a support foot inclined between the support plate and the housing.

3. The tightly assembled battery structure according to claim 2, characterized in that: The support feet are arranged in several groups along the battery trajectory, and adjacent support feet are arranged symmetrically.

4. The tightly assembled battery structure according to claim 3, characterized in that: The support plate is supported by the support feet and can cooperate with the shell to form a storage cavity. The storage cavity is pre-filled with an electrolyte replenishment block (3). The support plate has a replenishment hole. When the battery electrode group (1) loses water, the water in the electrolyte replenishment block (3) can be replenished to the battery electrode group (1) through the replenishment hole.

5. The tightly assembled battery structure according to claim 4, characterized in that: The electrolyte replenishment block (3) is a colloid made of sulfuric acid and silica sol.

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