FeCrCrO: A High-Capacity Cathode Material Synthesized Using an Ion-Exchange Chromatographic Method for Li-Ion Batteries.

An advanced ion-exchange method using resin was employed to produce a novel cathode material, FeCrCrO (0 ≤ ≤ 2), where some of the Cr ions at the octahedral sites of CrO were substituted with Fe ions. The battery cell test and X-ray photoelectron spectroscopy analysis of CrO, CrO, and FeCrO indicate a change in the capacity from 210 to 280 and 350 mA h g with a change in the Cr/Cr atomic ratio from 2 to 3 and 8 for CrO, CrO, and FeCrO, respectively. The discharge capacity of the compound with the crystallographic formula FeCr(CrO)(CrO) is, by far, the highest reported capacity for transition metal oxide electrodes in the voltage range of 2.0-4.5 V vs Li/Li.