TiO2/C复合材料用于钠离子电池负极的性能研究

近年来,TiO₂作为钠离子电池(NIB)负极材料,因其低成本和高稳定性等优势受到广泛关注。但受TiO₂本征电子导电性的固有限制,使得TiO₂作为NIB负极材料导电性较差,导致其容量和倍率等性能不理想。利用海藻酸钠与金属离子自主交联反应的特性,将反应产物在最佳温度下进行简单碳化,制备了具有分级多孔结构的TiO₂/C复合材料,其中TiO₂纳米颗粒均匀地分布在多孔互连的碳基体中,该结构提升了复合材料导电性的同时扩展了钠离子反应的附着位点。将TiO₂/C复合材料用于NIB负极材料,在100 mA·g^-1的电流密度下循环300圈后,电池可逆比容量维持在180.4 mAh·g^-1;进一步,在更高的1000 mA·g^-1电流密度下经过1000次循环后,电池可逆比容量维持在102.3 mAh·g^-1,充分显示出TiO₂/C复合材料作为NIB负极材料的应用潜能。

Study on the Performance of TiO2/C Hybrids as Anode Materials of Sodium-Ion Batteries

In recent years,titanium dioxide(TiO₂)has attracted a lot of attention as the active anode material in sodium rechargeable battery(NIB)due to its low cost and stability.However,in practice the intrinsically slow transport kinetics of electrons in TiO₂prevent optimal electrochemical performance.Here,we prepared a hierarchical porous TiO₂/C hybrid with oxygen vacancies through a simple carbonization of a Na+controlled Ti-alginate self-crosslinking for the high-performance anode of sodium-ion batteries.Owing to the combination of hierarchical porous carbon matrix and the TiO₂nano-particles,the TiO₂/C provided a capacity of 180.4 mAh·g^-1 after 300 cycles at a current density of 100 mA·g^-1,and delivered an excellent reversible capacity of 102.3 mAh·g^-1 after 1000 cycles even at a higher current density of 1000 mA·g^-1.Such good electrochemical performance has demonstrated the great potential of TiO₂/C hybrids used as anodes for NIB.