Multidimensional Silicon Anodes via Sn Modified Al-Si Dealloying for high Performance lithium-ion Batteries

In terms of low cost and high capacity, porous silicon (Si)-based anodes prepared from Al-Si dealloying method have been studied in lithium-ion batteries (LIBs) to achieve high energy density. However, porous Si-based anodes suffer from disadvantages of inferior lithium storage behavior and poor cycling stability due to their intrinsic particle size and limited pore space. Here, a novel design strategy is presented for the synthesis of the multidimensional structure Si (MSi-Sn_x) by introducing Sn and Sr into Al-Si melt. By changing the growth pattern and inhibiting the aggregation growth of the crystalline Si, the micron-sized structure is changed to a multidimensional structure with abundant void space and nano-sized secondary dendrite. Consequently, the MSi-Sn_x@C anode shows long cycling stability (maintaining 935 mAh g⁻¹ after 1000 cycles) and an outstanding rate capacity (734 mAh g⁻¹ at 2 A g⁻¹) because of the improvement of the ion transport behavior. This strategy shows the application potential of the Al-Si dealloying method for synthesizing low-cost and high-performance Si-based anodes in high energy density LIBs.