Designed Novel Carbazole Based Electrolyte Additive for Overcharge Protection of Lithium‑Ion Batteries

Abstract

9-Phenyl-9H-carbazole (9P9HC) organic monomer which contains phenyl moiety used as new overcharge protection additive in electrolyte of LiFePO₄ based lithium‑ion batteries (LIBs) was investigated in this paper. The cyclic voltammetry experimental results showed that the 9P9HC monomer could be electro‑polymerized to form a conductive polymer on the cathode surface. Therefore, it could prevent the batteries from voltage run away during overcharge. The charge–discharge tests of the investigated LiFePO₄/C batteries demonstrated that the 9P9HC additive could be control the investigated LIB voltage at the safe value less than 4.2 V. Furthermore, it was notable that 9P9HC has no significant impact on the charge–discharge performance of the investigated batteries at normal charge–discharge condition during 50 cycles.