Research progress of SiO -based anode materials for lithium-ion batteries

Silicon oxides (SiOx, 0 ≤ x ≤ 2) have received extensive attention in the field of energy storage due to their high energy density and without the severe volume change of silicon-based anodes. However, the low initial Coulomb efficiency and poor electronic conductivity of SiOx still need to be improved to achieve the satisfactory performance required for commercial applications. In this review, combining the structural feature, electrochemical and failure mechanism of SiOx, the reported synthesis methods classified by raw materials are summarized and re-evaluated, which provides guidelines for selecting appropriate synthesis methods through specific raw materials. Then the latest research progresses of the improvement strategies of SiOx anode are systematically summarized from the perspective of structure design, compounding with the second phase, pre-lithiation and optimization of electrolyte additives or binders. Finally, we discussed the new research directions and future research trends of SiOx materials. This work not only improves the theoretical basis for the preparation and modification of SiOx materials, but also provides direction guidance for accelerating the commercial application of SiOx anode.