Overcoming Jahn–Teller distortion of oxysulfide spinel materials for lithium secondary batteries

Abstract

A new sulfur-doped spinel material, LiAl_0.24Mn_1.76O_3.98S_0.02 with submicron dimensions and well developed octahedron morphology is synthesized by a sol–gel method using glycolic acid as a chelating agent. LiAl_0.24Mn_1.76O_3.98S_0.02 electrodes cycled in various voltage regions were characterized by means of charge–discharge experiments and XRD to investigate their structural integrity. The material overcomes Jahn–Teller distortion in all voltage operating regions. Our synthesized material shows excellent cyclability and delivers capacities of 215 mA h g^–1 over the 3 and 4 V regions (4.3–2.4 V).