Enhanced electrochemical performance of Ag-coated CuCr2O4 as anode material for lithium-ion batteries

Abstract CuCr 2 O 4 /Ag is prepared by a preliminary sol-gel formation of CuCr 2 O 4 and a subsequent chemical deposition of Ag on the surface by electroless plating. The surface morphology, structure and electrochemical behaviors of CuCr 2 O 4 /Ag and CuCr 2 O 4 are observed and compared by various analytical techniques. It is obvious that the electrochemical property of CuCr 2 O 4 is enhanced by Ag coating layer. The as-prepared CuCr 2 O 4 /Ag composite shows an initial discharge specific capacity of 495.6 mA h g −1 , and its coulombic efficiency evolves from 27.7% to 97.8% in the initial 40 cycles. In contrast, the initial discharge specific capacity and coulombic efficiency of CuCr 2 O 4 are 372.8 mAh g −1 and 21.7%, respectively. During the following 40 cycles, the cycling coulombic efficiency for CuCr 2 O 4 is merely 94.3%. Besides, the reversible charge capacity of CuCr 2 O 4 /Ag is 133.9 mA h g −1 after 40 cycles. For comparison, the reversible lithium storage capacity of bare CuCr 2 O 4 is only 100.5 mA h g −1 . It suggests that the improved reversible capacity and cycling performance should be ascribed to the Ag coating layer, which improves the electronic conductivity of CuCr 2 O 4 and may suppress the volume change of CuCr 2 O 4 particles during repeated cycles.