Effects of substrate morphology and ageing on cycle performance of a Sn-anode fabricated by electroplating

Abstract

The effects of Cu substrate morphology and ageing on the cycle performance of a Sn-anode electroplated on a smooth, a pyramid and a nodule-type Cu substrate and aged at 200 °C for 0, 1, 5, 20 h in a vacuum were examined. The Sn-anode electroplated on the nodule-type Cu substrate and aged for 1 h exhibited the highest reversible capacity (up to ∼600 mAh g −1) and a stable cycle performance, which resulted from the enhancement in adhesion and electrical contact properties between the Sn layer and the Cu substrate by the mechanical interlocking effect of the nodule-type Cu substrate and also by the buffering effects of an intermetallic compound formed by the ageing process. However, when aged for longer than 1 h at 200 °C, the reversible capacity of the Sn-anode decreased significantly due to the formation of an inactive Cu 3Sn phase, irrespective of the morphology of the Cu substrate.