Polyquinoneimines for lithium storage: more than the sum of its parts

Abstract

A straightforward synthetic strategy for the construction of electrode materials is demonstrated by the polymerization of two kinds of electrochemically active organic monomers without sacrificing specific capacity. Polyquinoneimines (PQIs), synthesised by the polycondensation reaction of 2,6-diaminoanthraquinone and the anhydrides, were used as a cathode in lithium ion batteries (LIBs). Electrochemical analysis such as CV and galvanostatic cycling reveals that PQIs exhibit the combined electrochemical properties of the two monomers. The mechanism of lithiation/delithiation of the PQIs has been investigated by means of electrochemical and spectroscopic (FTIR) analytical techniques. The as-prepared PQI-1 exhibits a higher specific capacity of 210 mA h g⁻¹ and a better cycling performance (136 mA h g⁻¹ after 200 cycles) compared with their polymeric precursors.