Self-polymerized membrane derivative of branched additive for internal short protection of high safety lithium ion battery

This study developed a novel branched additive membrane, which can be electrochemically self-synthesized to a solid electrolyte interface (SEI), to reduce the danger of lithium-ion batteries. The additive can be manufactured efficiently, and the membrane provides a high degree of safety, by reducing the probability of batteries suffering an internal short circuit. A composite electrode of LiCoO2 with the proposed self-polymerized SEI delivers excellent energy density near 150 mAh/g, without any side effects. In addition, open circuit potential (OCP) and charge–discharge curve behavior in full cell tests have revealed favorable electrochemical properties. Measurements to detect internal short circuits show that the self-polymerized SEI in a full cell is initiated within 1 s of a nail penetrating the battery. This novel membrane and self-polymerized SEI techniques make batteries safer for future applications.