Electrochemical Properties of CeMg_(12) + x % Ni Composites (x = 0 ～ 200) Prepared by Ball-Milling

摘要

The electrochemical properties of the as-cast and ball-milled CeMg_(12) + x% (mass fraction) Ni (vs . CeMg_(12)) (x =0, 50, 100 and 200) composites were investigated. The microstructure and discharge capacity of the ball-milled CeMg_(12) + x%Ni composites differ greatly depending on the amount of Ni introduced during ball-milling. The more nickel powder added, the more advantageous for the formation of the amorphous structure. And the discharge capacities of the ball-milled composites increase with increasing amount of nickel added. After 90 h ball-milling, the CeMg_(12) + 200% Ni composite exhibits a high discharge capacity of 1170 mAh •g~(-1)(CeMg_(12))~(-1) at 303 K. The improvement of electrochemical capacity is attributed to the formation of a homogeneous amorphous structure as well as the modification of the surface state after Ni addition.