Three-dimensional nanoporous and nanopillar composite Cu-Sn electrode for lithium-ion battery

A novel three-dimensional nanostructured, namely nanoporous and irregular nanopillar, composite Cu-Sn anode material for lithium-ion batteries was synthesized by directly oxidizing copper foil slightly in air and deoxidizing under H2/Ar atmosphere. Following that, Sn layer was deposited on as-prepared Cu substrate by the direct current sputtering technique. The morphology, constituent, and electrochemical performance of the obtained samples were characterized by field emission scanning electron microscope, X-ray diffraction, energy-dispersive X-ray spectrometer, and galvanostatic cycling test. The as-prepared Cu-Sn electrode (deposition time 10 min) exhibits a stable coulombic efficiency around 95 % over 50 cycles. The 50th specific capacity is 590 mA h/g at the current of 0.3 C, and at the high rate of 12 C, it exhibits 376 mA h/g which shows a high specific capacity and remarkable rate performance as an anode for lithium-ion batteries. The special 3D nanostructure, herein, can not only effectively offer enough space to accommodate large volume change but also act as structural reinforcement during electrochemical reaction. The simple fabrication approach of this novel nanostructure can be further extended to other anode materials with remarkable electrochemical property.