High-performance SiGe anode materials obtained by dealloying a Sr-modified Al–Si–Ge eutectic precursor

Abstract

In exploring the anode materials for high efficiency Li-ion batteries, it has been found that the electrochemical performance of Si can be enhanced via alloying with Ge. In the present work, we modified the Al–Si–Ge eutectic ribbons as the precursor by adding a trace of Sr to the alloy. The SiGe particles obtained by dealloying the Al–Si–Ge eutectic precursor have a porous coral-like nano-architecture with numerous fibrous branches towards various directions. Because of the large surface area and porosity, the as-prepared Sr-modified SiGe anode delivers an excellent capacity of 1166.6 mA h g⁻¹ at 0.1 A g⁻¹ after 100 cycles with a fantastic initial coulombic efficiency of 83.62%. Besides, it has a superior rate performance with a reversible capacity of 675.3 mA h g⁻¹ at the current density of 8 A g⁻¹. It is demonstrated that the modification treatment that is widely used in metallurgy is also a promising strategy to synthesize high-performance battery electrodes and other energy storage materials.