Electrochemical performance of heat treated SnO₂–SnCu@C-Felt anode materials for lithium ion batteries

Standalone, self-supported SnO₂–Cu₆Sn₅@C-Cloth/C-Felt anodes have been successfully synthesized through electroless metallization of the surface of C-Felt by Cu and Sn and subsequent heating at respective temperatures of 200 °C and 400 °C. X-ray diffraction (XRD), scanning electron miscroscopy (SEM), and the nitrogen (N₂) adsorption/desorption isotherms were used to obtain the composition, structure and morphology of the electrode. The electrochemical characteristics were assessed using a two-electrode cell arrangement versus lithium metal. Results presented show that SnO₂–Cu₆Sn₅ nanoparticles or thin film uniformly coated the C-Felt tubular network (matrix) establishing a binder-free anode. Galvanostatic charge/discharge cycling of the SnO₂–Cu₆Sn₅@C-Cloth/C-Felt anode exhibited a reversible discharge capacity of 641 mAh/g and 681 mAh/g after 140 cycles at the current density of 150 mA/g, for the samples heated at the respective temperatures of 200 °C and 400 °C. We attributed the high capacity performances of the synthesized 400 °C anode to the higher content of SnO₂, smaller particle sizes, higher Li ion diffusion coefficient and higher surface area. The outstanding cycle and rate capacity performances indicated that the heat-treated electrodes might be potentially applicable in lithium ion batteries.