Lithium battery isolation and function analysis

Lithium battery barriers In the structure of lithium batteries, barriers are one of the key internal components. The function of the barrier determines the battery's interface structure, internal resistance, etc., and directly affects the battery's capacity, cycle, and safety functions. The excellent barrier has an important purpose for improving the battery's summary function. The primary purpose of the barrier is to separate the positive and negative poles of the battery to prevent short-circuiting when the north and south poles are touched. In addition, it also has the function of allowing electrolyte ions to pass through. The barrier material is non-conductive, and its physical and chemical properties have a great influence on the function of the battery. Different types of batteries have different barriers to use. Regarding the lithium battery series, since the electrolyte is an organic solvent system, it must have barrier materials resistant to organic solvents. Generally, high-strength thin-film polyolefin porous membranes are used. The functional barrier of the lithium battery is located between the positive electrode and the negative electrode. The main purpose is to separate the positive and negative active materials to prevent the north and south poles from being short-circuited by touch. In addition, during the electrochemical reaction, the necessary electrolyte can be maintained to form ions. The moving channel. The barrier material is non-conductive, and different types of batteries require different barriers. Regarding lithium batteries, since the electrolyte is an organic solvent system, its barriers are required to have the following functions. ①In the battery system, its chemical stability is better, and the materials used are resistant to organic solvents. ②High mechanical strength and long service life. ③The ionic conductivity of the organic electrolyte is lower than that of the aqueous system. In order to reduce the resistance, the electrode area must be as large as possible, so the barrier must be thin. ④When the battery system is abnormal, the temperature rises. In order to guard against the risk, when the rapid heat generation temperature (120～140℃) starts, the thermoplastic barrier melts, the micropores are closed and become insulators, and the electrolyte is guarded to pass through. The intention to interrupt the current. ⑤From the perspective of lithium batteries, they must be fully immersed in organic electrolyte, and they must be highly immersed during repeated charging and discharging processes. The commonly used barrier materials in batteries are generally microporous membranes made of cellulose, woven fabrics, or synthetic resins. Lithium batteries generally use high-strength, thin-film polyolefin-based porous membranes. Commonly used barriers include polypropylene (PP) and polyethylene (PE) microporous barriers, as well as copolymers of propylene and ethylene, and polyethylene homopolymers. 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 article: Analysis of lithium battery charging and discharging requirements