Sn–Co–Cu Nanostructured Film as an Anode for Lithium-Ion Batteries

Abstract

Herein, we present the facial preparation of one-dimensional nanoscale square rod array Sn−Co−Cu alloy films through electrodeposition and subsequent annealing methods under the template-free condition, and their electrochemical performances of the assembled lithium cells as anode were tested in detail. The results indicated that the anodes displayed an excellent cyclic performance. The discharge capacities of the anodes were 1072 and 897 mA h g −1 at the corresponding current densities of 200 and 2000 mA g −1 after 500 cycles, with a high capacity retention of ∼92.3%. Moreover, the excellent capacity reversibility was confirmed when cycled at multiple C-rates of 0.2, 0.5, 1.0, 2.0, and 5.0 and then 0.2, and 5.0 A g −1 . This attractive electrochemical characteristic is likely due to the anode with morphology of the nanoscale square rod array. Such structure can accommodate the volume expansion of Sn−Co−Cu alloy film anodes and offer large surfaces and more active sites. The kinetic process of Li + lithiation and delithiation was also characterized based on cyclic voltammetry experiments in a lithium cell whose anode was the Sn−Co−Cu nanoscale square rod array film. The results showed that the kinetics process was mainly dominated by semi-infinite linear diffusion and surface reaction and that the contribution of pseudocapacitance increased with the increase of scan rate.