Overcharge Protection Effect of Cyclohexylbenzene and New Overcharge Protection Agent for Lithium Ion Batteries

We investigated the overcharge protection property of cyclohexylbenzene (CHB). CHB prevents overcharging by consuming the overcharge current through the electrochemical reaction of CHB. However, the CHB reactants do not increase resistance, and the overcharge reaction will restart after the CHB reaction has finished. A new overcharge protection agent (OPA) needed to be developed that has a shut-down function. We developed the new OPA, which consists of a polymer with an aromatic group and a high polar functional group. The new OPA forms a high-resistance film during overcharging, and its concept is validated.