Electrochemical performance of compounds Ho6Fe23−xCox (x=0, 1, 3)

Alloys with composition of Ho6Fe23−xCox (x=0, 1, 3) were prepared and examined by X-ray diffraction technique and automatic battery testing instrument. The compounds Ho6Fe23−xCox (x=0, 1, 3) crystallized in cubic Th6Mn23-type structure with space group (No. 225). The electrochemical properties of these alloys such as discharge capacity, cycling performance and high rate dischargeability were investigated by battery testing instruments in alkaline electrolyte. Substitution of small amounts of Co for Fe in Ho6Fe23−xCox improved the activation, discharge capacity and the high rate dischargeability. The alloy with x=3 (Ho6Fe20Co3) had better discharge capacity, HRD and plateau pressure at discharge current density of 150 mA/g.