钛氧化物改性SiO负极在锂离子电池中的研究进展

Research progress of titanium oxides modified SiO anode in lithium-ion batteries

摘要:

SiO负极虽具有高比容量、合理的工作电压，但仍面临首次库仑效率低、体积膨胀大（~160%）及导电性差等硅基负极材料共性问题，使其在锂离子电池（LIBs）中的大规模商业化应用严重受阻。而在众多金属氧化物中，钛氧化物负极因在充放电过程中体积变化小（＜4%），锂化后兼具优异的锂存储能力和热稳定性等优势，近些年被多次报道用于改善SiO的电化学综合性能。首先，该文从SiO的微观结构与锂化机制出发，简要概括了SiO与众多金属氧化物复合改性案例；然后，重点综述了钛氧化物改性SiO负极的研究工作，着重从TiO2与TiO2-x改性SiO负极两方面进行归纳与分析；最后，总结了钛氧化物提高SiO电化学性能的机理及改性工艺与电化学性能之间的构效关系，并对实现满足高能量密度SiO基负极商业化的目标进行展望：充分利用有关软件算法模拟具有最低化学复杂性体系，有利于深入分析反应过程与电化学机理；加强新型低成本钛氧化物（如Ti2O3）用于改性SiO负极，有利于推动SiO基负极学术探究与商业应用。

Abstract:

Although SiO anode has high specific capacity and reasonable working voltage, it still faces the common problems of silicon-based anode materials such as low initial Coulomb efficiency, large volume expansion (~160%) and poor conductivity, which seriously hinders its large-scale commercial application in lithium-ion battery (LIBs). Among many metal oxides, titanium oxides anods have been reported many times in recent years to improve the electrochemical performance of SiO due to its small volume change during charge and discharge and excellent lithium storage capacity and thermal stability after lithiation. Above all, based on the microstructure and lithiation mechanism of SiO, this paper briefly summarizes the cases of composite modification of SiO and many metal oxides,; Secondly, it focuses on the research work of titanium oxides modify SiO anode, stressing the induction and analysis of TiO2 and TiO2-x modified SiO anode, and summarizes the mechanism of titanium oxides improving the electrochemical performance of SiO and the structure-activity relationship between modification process and electrochemical performance. In the end, the realization of the goal of commercialization of SiO-based anode with high energy density is prospected: making full use of relevant software algorithms to simulate the system with the lowest chemical complexity, which is conducive to in-depth analysis of the reaction process and electrochemical mechanism; strengthening the modification of SiO anode by new low-cost titanium oxides (such as Ti2O3) is beneficial to promote the academic research and commercial application of SiO-based anode.