Anode Properties of Cu-Coated Si Thick Film Electrodes Prepared by Electroless Deposition and Gas-Deposition

Thick film electrodes of Cu-coated Si particles were fabricated by an electroless deposition and a successive gas-deposition, and were evaluated their electrochemical properties as an anode of Li-ion battery. The discharge capacity and its retention at the 1000th cycle were 570 mAh g-1 and 61%. The excellent cycle life performance is attributed to an enhanced electrical conductivity due to the Cu-coating and a reversible conversion reaction between Li and Cu2O which was formed on the Cu surface. The high capacity retention is caused by a high fracture toughness of the coated Cu which can effectively relax a stress induced by volume expansion of Si as a buffer matrix.