A new oxysulfide spinel LiCr0.19Mn1.81O3.98S0.02 with well-developed octahedral structure is synthesized by a sol–gel method using glycolic acid as a chelating agent. The LiCr0.19Mn1.81O3.98S0.02 electrode shows no capacity loss in the 3- and 4-V region. This behavior is investigated by X-ray diffraction (XRD). The substitution of S for O in LiMn2O4 stabilizes the structural integrity of the spinel host, which in turn increases the electrochemical cycleability.