N-Phenylmaleimide as a new polymerizable additive for overcharge protection of lithium-ion batteries

Electrochemical properties and overcharge behavior of N-phenylmaleimide (NPM) as a new polymerizable electrolyte additive for overcharge protection of lithium-ion batteries are studied by cyclic voltammetry, charge–discharge performance, electrochemical impedance spectroscopy and scanning electron microscopy (SEM). The results show that NPM can electrochemically polymerize at the overcharge potential of 3.8–4.2 V (vs. Li/Li+) and form a thin polymer film on the surface of the cathode, thus preventing voltage runaway. On the other hand, the use of NPM as an overcharge protection electrolyte additive does not influence the normal performance of lithium-ion batteries.