Silicon acid batteries enabled by a copper catalysed electrochemo-mechanical process

Abstract

Although silicon exhibits outstanding charge storage capacity during its electrochemical oxidation, utilization of this process in battery applications is fundamentally hindered by its propensity to form a passivated oxide layer on the surface. Here we report a copper catalysed electrochemistry and mechanics coupled route to retain the reactivity of silicon in acidic solutions. The formation of a wavy silicon oxide layer on silicon can be promoted by the inhomogeneously distributed copper catalyst and thus local strain is formed. This strain will induce the formation of a highly defective oxide layer that can facilitate the electrolyte transport to silicon. Thus the combination of the catalytic reaction and the defective oxide structure causes the spontaneous and continuous electrochemical oxidation of silicon. Silicon acid batteries with high energy density, reduced electrolyte consumption and long shelf-life are built based on such reactions.