The enhanced electrochemical performance of Ag coating KxCu1−xO1−γ as high performance anode materials for lithium-ion batteries

K x Cu 1−x O 1−γ (0 ≤ x ≤ 0.12) and K 0.08 Cu 0.92 O 1−γ anode materials are synthesized via a simple ethylene glycol assisted sol-gel method and characterized by X-ray diffraction, Scanning Electron Microscopy, High-resolution/Transmission Electron Microscopy, Energy Dispersive Spectroscopy and Select Area Electron Diffraction . The introduction of potassium element improves the electro-chemical performance of CuO greatly, especially for x = 0.08. After Ag coating, K 0.08 Cu 0.92 O 1−γ @Ag anode displays superior electro-chemical performance with excellent reversible capacity, cyclic performance and rate capability. It delivers a capacity of 804.3 mA h g −1 even at the 50th cycle. The role played by the K element doping and Ag coating are fully discussed.