Improved Performance of Silicon Anodes Using Copper Nanoparticles as Additive

Nanoscale copper has been successfully integrated into a silicon-based anode via a cost-effective, one-step process. The additive was found to improve the overall electrical conductivity and charge/discharge cycling performance of the anode. Analysis of the new material shows that copper particles are homogeneously interspersed into the silicon active layer. The formation of Cu3Si during the annealing step of the fabrication process was also confirmed using X-ray diffraction and is thought to contribute to the structural stability of the anode during cycling. Despite the inclusion of only small quantities of the additive (approximately 3%), anodes with the added copper show significantly higher initial discharge capacity values (957 mAg(-1)) compared to anodes without copper (309 mAg(-1)), and they continue to outperform the latter after 100 charge/discharge cycles. Results also show a significant decrease in the resistance of anodes with the additive, a contributing factor in the improvement of the electrochemical performance.