Porous silicon layer overlaid graphite anode materials for fast-charging of lithium-ion batteries

Abstract

Demand for lithium-ion batteries that can charge rapidly has grown with the widespread adoption of electric vehicles. Graphite anode materials in lithium-ion batteries have shown limitations not only with respect to energy densities, but also their fast-charging abilities. Here, we demonstrate that overlaying a porous silicon layer can boost the specific capacity as well as the fast-charging ability of graphite anode materials. A graphite anode material overlaid with a porous silicon layer delivered a reversible capacity of approximately 421 mAh g−1 at a current density of 0.1 C (36 mA g−1). Under a fast-charging rate of 10 C (3600 mA g−1), the resulting anode reached 65.9 % of its capacity at a rate of 0.1 C (36 mA g−1). These findings highlight the ability of graphite coated with porous silicon to reduce charging times of lithium-ion batteries.