H+/Cu2+ co-assisted corrosion synthesis of sustainable silicon dendrite anodes

Abstract

Silicon (Si)-based materials have been identified as next-generation preferred anode materials owing to their ultra-high specific capacity, environmental friendliness and low price. However, the defects in Si-based materials (e.g., the large volume change with unstable solid electrolyte interface during repeated lithiation/delithiation processes and low intrinsic conductivity), will significantly destroy the integrity of electrode structure and get slow dynamic performance, resulting in a fast capacity fading. Herein, we prepared various silicon‑aluminum‑copper dendrites (named SCD-1/2/3) via a two-step displacement dealloying process, which was devoted to simultaneously improving structural instability, low ionic/electronic conductivity of Si crystals. Therefore, the SCD-2 anode possessed an initial Coulombic efficiency of 80 % and exhibited a superior capacity of 1851.7 mA h g−1 at 1 A g−1 after 100 cycles. This paper provides a simple method to gain the Si anodes with high initial Coulombic efficiency, relieved volume expansion and long cycling life.