Full-tab square battery cell

Abstract

The invention discloses a full-tab square battery cell which comprises a positive plate, a negative plate, an isolating membrane, a full-tab structure, a square shell, electrolyte and a cover plate assembly.The full-tab square battery cell has the advantages that the full-tab structure and reasonable tab position design are arranged, so that the internal resistance of the battery cell is remarkably reduced; the internal resistance is reduced, so that the heat generated in the charging and discharging process of the battery is greatly reduced, and the temperature rise amplitude of the battery is reduced. Therefore, not only is performance degradation caused by overheating of the battery reduced, but also the risk of thermal runaway is reduced, and the safety of the battery is enhanced. In an energy storage system, safety accidents such as fire disasters caused by overheating of the battery can be effectively avoided, the internal space layout of the battery core is optimized, the internal volume utilization rate of the battery core is improved, and more active substances can be accommodated under the same appearance size, so that the energy density of the battery is improved, and the service life of the battery is prolonged. And the endurance mileage of the electric automobile or the storage capacity of the energy storage equipment can be increased.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and more particularly to a square battery cell with full-tab lugs. Background Art

[0002] In today's society, with the rapid advancement of technology, the demand for battery performance continues to rise. Prismatic cells, as a common battery type, play a key role in numerous fields. However, the tab design of traditional prismatic cells presents numerous drawbacks. Conventional tabs have high resistance and are poorly positioned, significantly hindering current transmission. This not only generates significant heat during battery charging and discharging, impacting battery stability and safety, but also severely limits the battery's fast-charging capabilities.

[0003] Taking electric vehicles as an example, the long charging times and limited range of traditional prismatic battery cells have become major factors hindering their widespread adoption. In the energy storage sector, the inefficient charging and discharging of traditional prismatic battery cells also increases energy loss and costs. Although the industry has been trying to improve these methods, such as shortening the tab length, the results have been limited and have not fundamentally resolved the problem.

[0004] Therefore, it is necessary to invent a full-pole square battery cell to solve the above problems. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a full-tab square battery cell to solve the problem proposed in the above-mentioned background technology that the conventional tab resistance is high and the setting position is unreasonable, which causes the current to encounter great obstacles during the transmission process, which not only causes a large amount of heat to be generated during the charging and discharging of the battery, affecting the stability and safety of the battery, but also seriously limits the fast charging capability of the battery.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solution: a full-pole-ear square battery cell, comprising.

[0007] As a further description of the above technical solution, it includes a positive electrode sheet, a negative electrode sheet, a separator, a full-electrode ear structure, a square shell, an electrolyte and a cover assembly, wherein the positive electrode sheets and the negative electrode sheets are alternately arranged and separated by a separator in the middle, and the full-electrode ear structure includes a positive electrode full-electrode ear and a negative electrode full-electrode ear, which are respectively formed by the portion of the current collector edge of the positive electrode sheet and the negative electrode sheet that is not coated with the active material, and the positive electrode full-electrode ear and the negative electrode full-electrode ear are respectively connected to the corresponding bus bar, the square shell is used to accommodate the battery body and is provided with an injection hole, the electrolyte is filled in the inside of the square shell, the cover assembly is installed at the opening of the square shell and includes a positive electrode post, a negative electrode post, an explosion-proof valve and an injection hole sealing plug, and the positive electrode post and the negative electrode post are respectively connected to the positive bus bar and the negative bus bar; As a further description of the above technical solution, the current collector of the positive electrode sheet is aluminum foil, and the current collector of the negative electrode sheet is copper foil or aluminum foil; As a further description of the above technical solution, the positive electrode full tab and the negative electrode full tab are connected to the corresponding busbar by ultrasonic welding or laser welding; As a further description of the above technical solution, the square housing is made of aluminum alloy or steel; As a further description of the above technical solution, the isolation membrane is a polypropylene or polyethylene or aramid microporous membrane; As a further description of the above technical solution, the electrolyte is made of a material with high ionic conductivity and high stability; As a further description of the above technical solution, the positive electrode sheet, the negative electrode sheet and the separator are assembled into a battery cell body by lamination or winding; As a further description of the above technical solution, the cover plate assembly and the square shell are sealed by welding.

[0008] Compared with the prior art, the present invention has the following beneficial effects: The present invention significantly reduces the internal resistance of the battery cell by providing a full-tab structure and rationally designing the tab position. This reduction in internal resistance significantly reduces the heat generated during the battery's charge and discharge process, reducing the temperature rise of the battery. This not only reduces battery performance degradation due to overheating, but also reduces the risk of thermal runaway, thereby enhancing battery safety. In power and energy storage battery systems, it can effectively prevent safety accidents such as fires caused by battery overheating. 2. The present invention optimizes the internal spatial layout of the battery cell and improves the internal volume utilization of the battery cell by setting up a full-electrode tab structure. Under the same external dimensions, it can accommodate more active substances, thereby improving the energy density of the battery, which helps to increase the cruising range of electric vehicles and improve the storage capacity of energy storage devices. DETAILED DESCRIPTION

[0009] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0010] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with specific implementation methods.

[0011] Basic Cell Structure: The present invention's square-shaped, fully tabbed cell primarily consists of a positive electrode sheet, a negative electrode sheet, a separator, a fully tabbed structure, a square-shaped housing, an electrolyte, and a cover assembly. The positive and negative electrodes are arranged alternately, separated by a separator to prevent short circuits. The current collectors for the positive and negative electrodes are aluminum foil, while those for the negative electrodes are copper or aluminum foil to ensure good conductivity.

[0012] Full-tab structure: The full-tab structure is one of the core innovations of this invention. The full positive and negative tabs are formed from the uncoated active material edges of the current collectors on the positive and negative electrodes, respectively. These full tabs are connected to corresponding busbars using ultrasonic or laser welding to ensure reliable and low-resistance connections. The full tabs are positioned at the longitudinal ends of the electrode sheets (shorter distance apart), significantly shortening the current path and reducing tab resistance.

[0013] Housing and Package: The rectangular housing, made of aluminum alloy or steel, offers excellent mechanical strength and heat dissipation. It houses the battery cell and features an injection port for convenient electrolyte injection. The cover assembly, mounted at the opening of the rectangular housing, includes the positive and negative electrode posts, an explosion-proof valve, and a sealing plug for the injection port. The positive and negative electrode posts connect to the positive and negative busbars, respectively, to conduct current out of the battery. The cover assembly is sealed to the rectangular housing using sealant or welding to ensure the cell's tightness and safety.

[0014] Other components: The separator is made of polypropylene, polyethylene, or aramid microporous membrane, offering excellent ionic conductivity and insulation, effectively preventing short circuits between the positive and negative electrodes. The electrolyte utilizes highly conductive and stable materials, providing an optimal ion transport environment for the battery's chemical reactions. The positive and negative electrodes, along with the separator, can be assembled into the battery cell using either a stacked or wound method to meet diverse application requirements. The explosion-proof valve automatically opens when internal pressure in the battery is excessive, releasing pressure and ensuring battery safety.

[0015] (1) Cell preparation process Electrode sheet production: Following conventional processes, the positive electrode active material (such as ternary materials, lithium iron phosphate, etc.) is mixed with a binder and conductive agent to form a positive electrode slurry. This slurry is then coated onto an aluminum foil current collector. After drying and roller pressing, the positive electrode sheet is produced. The negative electrode sheet is similarly produced. The negative electrode active material (such as graphite, etc.) is mixed with relevant additives to form a negative electrode slurry. This slurry is then coated onto a copper foil current collector to form the negative electrode sheet. A full tab area is reserved at the edge of the electrode sheet to ensure that the edge of the current collector is not coated with active material.

[0016] Connecting the full tabs to the busbar: Connect the full positive and negative tabs to their corresponding busbars using ultrasonic or laser welding. During the welding process, strictly control the welding parameters to ensure weld quality and reduce contact resistance.

[0017] Cell Assembly: The positive electrode sheet, separator, and negative electrode sheet are assembled into the cell body in sequence by stacking or winding. During the assembly process, the separator must be positioned accurately to prevent short circuits between the positive and negative electrodes.

[0018] Encapsulation and injection: Place the assembled cell body into a square aluminum alloy enclosure. Install the cover assembly using sealant or welding to ensure the enclosure is airtight. Inject a highly ionic conductive and stable electrolyte through the injection port, which is then sealed with a sealing plug.

[0019] Performance testing: Prepared full-tab square cells undergo various performance tests, including internal resistance, charge and discharge performance, cycle life, and safety. Based on the test results, the production process is optimized and adjusted to ensure optimal cell performance.

[0020] (2) Application Cases Electric Vehicle Applications: The full-tab prismatic battery cells of this invention are used in electric vehicle power battery packs. In actual use, charging times are significantly shortened and driving range is significantly increased. Furthermore, battery safety is effectively guaranteed, reducing potential safety hazards associated with battery overheating.

[0021] Energy storage system applications: Using the battery cell of this invention in energy storage systems improves the charging and discharging efficiency and stability of the energy storage system. Due to the long life and high safety of the battery cell, the maintenance cost and operation risk of the energy storage system are reduced.

[0022] Portable Electronic Device Applications: Using the battery cell of this invention in portable electronic devices improves battery life and charging speed. Furthermore, the high energy density of the cell allows for smaller and lighter devices, enhancing product competitiveness.

[0023] Finally: 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, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A square battery cell with full tabs, characterized by: It includes a positive electrode sheet, a negative electrode sheet, an isolation membrane, a full-electrode ear structure, a square shell, an electrolyte and a cover assembly. The positive electrode sheets and the negative electrode sheets are alternately arranged and separated by an isolation membrane in the middle. The full-electrode ear structure includes a positive electrode full-electrode ear and a negative electrode full-electrode ear, which are respectively formed by the parts of the collector edges of the positive electrode sheet and the negative electrode sheet that are not coated with active materials, and the positive electrode full-electrode ear and the negative electrode full-electrode ear are respectively connected to the corresponding bus. The square shell is used to accommodate the battery cell body and is provided with an injection hole. The electrolyte is filled in the inside of the square shell. The cover assembly is installed at the opening of the square shell and includes a positive electrode post, a negative electrode post, an explosion-proof valve and an injection hole sealing plug. The positive electrode post and the negative electrode post are respectively connected to the positive bus and the negative bus.

2. The square battery cell with full tabs according to claim 1, characterized in that: The current collector of the positive electrode sheet is aluminum foil, and the current collector of the negative electrode sheet is copper foil or aluminum foil.

3. The square battery cell with full tabs according to claim 2, characterized in that: The positive electrode full tab and the negative electrode full tab are connected to the corresponding busbar by ultrasonic welding or laser welding.

4. The square battery cell with full tabs according to claim 3, characterized in that: The square shell is made of aluminum alloy or steel.

5. The square battery cell with full tabs according to claim 4, characterized in that: The isolation membrane is a polypropylene microporous membrane, a polyethylene microporous membrane or an aramid microporous membrane.

6. The square battery cell with full tabs according to claim 5, characterized in that: The electrolyte is made of materials with high ion conductivity and high stability.

7. The full-tab square battery cell according to claim 6, characterized in that: The positive electrode sheet, the negative electrode sheet and the isolation film are assembled into a battery cell body by lamination or winding.

8. The full-tab square battery cell according to claim 7, characterized in that: The cover plate assembly and the square shell are sealed by welding.