Improved Performance of Silicon Anodes Using Copper Nanoparticle Additive

Abstract

Silicon continues to be an attractive anode material for use in lithium-based battery systems due to its high theoretical capacity and natural abundance. However, the widespread application of the silicon anode remains impeded due to notable, unfavorable characteristics observed during charge/discharge cycling. One such hindrance is the relatively poor electrical conductivity of silicon. Approaches to mitigating this issue often involve increasing the amount of conductive additive, but the additives are usually carbon-based or process-intensive. The focus of this research is the improvement of the electrical conductivity of the anode active layer by introducing nanoscale copper additive to the silicon structure. The fabrication of these anodes involved a simple, cost-effective procedure where the copper nanoparticle additive was homogeneously dispersed within the silicon active layer, and the anodes were tested using CR2032 type coin cells. The results of this research indicate excellent stability and improvements in the charge capacity of the cells with additive as a function of cycle testing. Surface characterization was performed using spectroscopy and imaging methods for comparison of anodes before and after charge/discharge cycling tests. SEM images show the successful integration of the copper nanoparticles within the silicon layer. Acknowledgement: This research was supported by the Office of Vice President for Research Innovation at the University of Nevada, Reno via an AIRE grant. Characterization of electrodes was conducted by Materials Characterization Nevada.