Copper hydroxyphosphate Cu 2 (OH)PO 4 as conversion-type anode material for lithium-ion batteries

The copper hydroxyphosphate Cu 2 (OH)PO 4 was synthesized under mild hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. The electrochemical performance of Cu 2 (OH)PO 4 as anode material for lithium-ion batteries (LIBs) was investigated. The Cu 2 (OH)PO 4 anode delivers a capacity of 741.1 mAh g −1 at 0.1 A g −1 over 300 cycles. The electrochemical and structural analyses suggest that the Cu 2 (OH)PO 4 anode undergoes the conversion reaction with Li + ions during lithium storage process. The in situ generated ion conductive Li 3 PO 4 is much beneficial to enhance Li + diffusion that leads to good rate capability and cycling stability. Besides the diffusion-controlled process, the surface capacitive effect also considerably contributes to the achieved capacity of the electrode. The results indicate that the polyanionic metal phosphate compounds are potential candidates for conversion-type anode materials for LIBs.