Abstract
Anode-free thin film battery with configuration Cu/Lipon/LiCoO2 was investigated. The battery was activated by the plating of metallic Li at the Cu current collector during the initial charge. Cu/Lipon interface is very stable, neither chemical nor structural transformation was found. Cu surface morphology is vital for cycle stability as observed by scanning electron microscopy. Flat Cu surface came along with low annealing temperature of LiCoO2 and low deposition rate of Lipon. Less than 25 % capacity drop is demonstrated over 80 electrochemical cycles at 0.5 mA/cm2. Initial charge with small step voltage could increase the nucleation density of metallic Li but also cause the break of Cu surface.