A Facile Route for Processing of Silicon-Based Anode with High Capacity and Performance

Abstract

A facile route to suppress the capacity fading because of the pulverization and uncontrolled growth of solid electrolyte interphase in silicon anodes is described. In this new approach, a mixture consisting of milled silicon particles and superconducting carbon particles is dispersed with a liquid precursor of carbon (Furfuryl alcohol), which is suddenly gelled to freeze the instantaneous positions of the constituents. The gel is dried and pyrolysed at ~950°C to convert carbon precursor to carbon coating on silicon particles. Silicon particles milled for 24h and coated with carbon using this simple approach showed a reversible capacity of 1050 mAh/g after 200 cycles. Impedance spectroscopy is used to identify the roles of different sources of impedance on the overall electrode performance. This anode also displayed a specific capacity of ~750 mAh/g even at a higher current density of 6 A/g, The same electrode is tested at various higher temperatures up to 60°C and maintained good performance without any safety issues. Furthermore, this anode is tested in a full cell against a LiNi0.5Co0.2Mn0.3O2 cathode and displayed a stable reversible capacity of ~76 mAh/g after 100 cycles. Therefor, in this paper a new approach of preparing silicon-based anodes for next generation Li-ion batteries with superior capacity and performance is presented.