A new class of amorphous cathode active material LixMyPOz (MÂ =Â Ni, Cu, Co, Mn, Au, Ag, Pd)

A new class of amorphous cathode active material LixMyPOz (LiMPO) is proposed. The materials are sputter deposited to thin film form by Li3PO4 together with metal or metal oxide targets. Among several materials tested as thin-film battery, working material found are M = Ni, Cu, Co, Mn, Au, Ag, Pd. The property is intensively studied for LixCuyPOz (LiCuPO) and LixNiyPOz (LiNiPO). Those materials shows wide composition margin such as composition y between 1 and 3, and high capacity for LiNiPO with maximum value of 330 mAh g−1. The capability to charge and discharge at high rate is shown up to 30 C. This preliminary report reveals its high potentiality for further optimization.