目的 研究界面导电性对材料电化学性能的影响,提升 TiNb2O7 的循环稳定性。 方法 研究纯相 TiNb2O7 材料的电化学特性,对比不同荷电态(SOC)的极片,研究材料导电性对电化学性能的影响机制。 在材料的制备过程中加入不同的碳源构建导电网络,提升其导电性。 结果 得到了导电性对材料的影响机理,加入不同碳源显著提升了材料的循环稳定性。 结论 LixTiNb2O7 的导电性随嵌锂深度的增加而增大,导致材料的脱锂行为不能彻底进行。 通过加入碳纳米管或者蔗糖热解碳,可以有效提升材料的循环性能。

Objective To investigate the effect of interfacial conductivity on the electrochemical performance and elevate the cycling stability of TiNb2O7. Methods The electrochemical characteristics of pure TiNb2O7 anode materials were studied, and the influencing mechanism of interfacial conductivity on the electrochemical performance was analyzed by comparing the electrodes with different state of charge (SOC). The conductive network was constructed by adding different carbon sources in the preparation process of the material, to elevate its conductivity. Results The influencing mechanism of the conductivity on the material was obtained. Addition of different carbon sources significantly elevated the cycling stability of the material. Conclusion The conductivity of LixTiNb2O7 increased with the increasing depth of lithiation, which resulted in the incomplete delithiation of the material. The cycling performance was markedly elevated after the addition of carbon nanotube or sucrose pyrolytic carbon.