Improving Electrochemical Performance of Cusi Thin Film By Depositing Cu Thin Film Via Magnetron Sputtering

Huge volumetric change occurs in Si anode material during lithiation process results in pulverization or delamination of the thin film from the current collectors, which eventually brings a short cycle life. Previously the use of CuSi as anode material to overcome this problem has been proposed. The results seem promising, even though more improvement has still been required for commercial applications. In this study, we present a strategy to improve the cycle performance of CuSi thin film: depositing a very thin Cu layer on top of the CuSi film. It is believed that Cu presence would improve the electrochemical performance of the anode due to its ductile and electrical conductive behavior.

In this sense, we produced two CuSi films by a magnetron sputtering method. To compare the effect of compliant layer presence on the anode performance, 10nm of Cu film was deposited on the top of the one CuSi film. The electrochemical performance proves that the coulombic efficiency as well as the cycle life of the CuSi film was increased due to the compliant layer existence.