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

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.