A SiO2@Al as stable and long-cycle anode for lithium-ion batteries

Silicon oxides (SiO, SiO2, SiOx, etc.) are considered as new generation of anode materials for lithium-ion batteries due to their high theoretical specific capacity and low-cost. However, the low conductivity and unsatisfied electrochemical performance have impeded their advance. In order to solve the mentioned issues, here, a porous SiO2 filled with Al anode is designed and fabricated via simple but effective melt-self-assembly method, in which, SiO2 being from the diatomite with natural porous structure. The presence of Al not only contribute certain specific capacity but also improve the conductivity of the SiO2 anodes. As expected, a high capacity of 730 mA h g−1 is obtained in the fabricated SiO2@Al electrode and the capacity retention rate reaching 95% after 312 cycles. Importantly, the rate capability is significantly enhanced delivering capacity up to 635 mA h g−1 at current density of 800 mA g−1 superior to the single SiO2 electrode. The results indicate the great potential of the fabricated SiO2@Al composite electrode as a high-performance and low-cost electrode material for the next-generation high-specific-energy lithium-ion batteries.