Safety planning of cell structure

Some examples for cell structure safety planning are proposed: A) The positive-negative capacity ratio and the planned size sheetAccording to the characteristics of the anode and cathode data, choosing the appropriate anode and cathode capacity ratio is more important than the anode and cathode capacity of the battery. Linked to a safe lithium battery, too much positive electrode capacity will show accumulation on the surface of the lithium metal anode, while the anode capacity of the battery will be lost. Under normal circumstances, N/Pu003d1.05~1.15, and appropriate selection should be made according to the actual battery capacity and safety requirements. Plan the size of the tablet so that the weight of the negative paste (active substance) covers the weight of the positive paste (greater than). Generally, the width should be 1~5mm larger and the length should be 5~10mm larger. B) The gap width should leave room for planning and the overall principle is to prevent direct contact and internal short circuits where the gap width is negative, because the battery is in the charging and discharging process and the thermal shock environment, such as the gap heat causes premature barrier length and width direction Deformation and alienation The wrinkle area is polarized due to the increase in the distance between the positive and negative electrodes; due to the refinement of the gap, the possibility of micro short circuit may be added to the gap stretched area; due to the direct contact between the positive electrode and the negative electrode, the edge area of u200bu200bthe gap is shortened It may cause an internal short circuit, which puts the battery in danger of overheating. Therefore, when planning the battery, it is necessary to consider its shortening characteristics when using the gap area and width. Taking into account the process error, it is necessary to make the barrier at least 0.1 mm longer than the outside of the rod. C) Insulation treatment. Internal short circuit is an important factor in the safety of lithium batteries. There are many potential parts of the internal short circuit risk in the structural planning of the cell. Therefore, the necessary methods should be set at key positions and may be insulated, in order to prevent the internal battery Abnormal short-circuit conditions, such as: maintaining the necessary distance between the anode ears; insulating tape should be affixed to the center of the end, must not be pasted, and cover all exposed parts; between the positive electrode aluminum foil with insulation and the negative electrode active material; use insulating tape to cover the electrode All welding parts of the ear; insulating tape is selected on the top of the battery. D) Setting a safety valve (decompression device) lithium battery has a high risk of attack, which is often caused by an explosion or fire due to excessive internal temperature or pressure; a reasonable pressure relief device can quickly release the pressure and heat inside the battery when danger occurs , Which reduces the risk of explosion. Reasonable requirements for pressure reducing equipment can be satisfied with normal operation. The internal pressure of the battery and the risk of the internal pressure reaching the limit are actively opened and released. The setting of the pressure reducing equipment should consider the new deformation characteristics of the battery shell due to the internal pressure plan; the safety valve planning can be This is achieved by flakes, edges, seams and scratches. 3. Improve the technical level and do our best to do a good job in standardization and standardized processing. In the process of mixing, paint, dry, compact, slit the circle, develop standardization (such as gap width, electrolyte injection volume, etc.), and improve process technology (such as low pressure injection method, centrifugal shell method, etc.) , Do a good job in process control, ensure process quality, and reduce differences between products; set special work steps in key processes that affect safety (such as depole-chip burrs, powder sweeping, selection of different welding methods, different data, etc.), execution Standardized quality control, eliminate the location of defects, and remove defective products (such as steel pipe plate deformation, gap puncture, active data drop, electrolyte leakage, etc.); adhere to the cleanliness and cleanliness of the processing site, implement 5S management and 6 sigma quality Control and prevent the mixing of impurities and water during processing, and minimize the impact of accidents on safe processing. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: International shipping requirements and precautions for lithium battery products