Huang Xiaoqing, Zhang Wenbiao, Zhou Chaojin, Yang Lichun, Wang Hui, Gao Qingsheng, Zhu Min
Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, PR China.
School of Materials Science and Engineering, and Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou 510640, PR China.
J Colloid Interface Sci. 2020 Sep 15;576:176-185. doi: 10.1016/j.jcis.2020.05.017. Epub 2020 May 8.
Volume expansion and poor conductivity result in poor cyclability and low rate capability, which are the major challenges of transition-metal oxide as anode materials for sodium-ion batteries (SIBs). Herein, N-doped carbon encapsulated CoMoO (CoMoO@NC) nanorods are developed as excellent anode materials for SIBs with long-cycle life. The N-doped carbon shells serve as buffer to accommodate severe volume changes during sodiation/desodiation, and at the same time improve electronic conductivity and activate surface sites of CoMoO. The optimized composite presents rapid reaction kinetics and excellent cycle stability. Even at a high current density of 1 A g, it still shows long-cycle life and maintains specific capacity of 190 mAh g after 3200 cycles. Furthermore, CoMoO@NC anode is applied to match with NaV(PO) cathode to assemble full-cells, in which it accomplishes reversible capacity of 152 mAh g after 100 cycles, with capacity retention of 75% at a current density of 1 A g, highlighting the practical application for SIBs.
体积膨胀和导电性差导致循环性能差和倍率性能低，这是过渡金属氧化物作为钠离子电池（SIBs）负极材料的主要挑战。在此，氮掺杂碳包覆的CoMoO（CoMoO@NC）纳米棒被开发为具有长循环寿命的优异SIBs负极材料。氮掺杂碳壳起到缓冲作用，以适应在 sodiation/desodiation 过程中严重的体积变化，同时提高电子导电性并激活 CoMoO 的表面位点。优化后的复合材料呈现出快速的反应动力学和优异的循环稳定性。即使在1 A g 的高电流密度下，它仍显示出长循环寿命，在 3200 次循环后仍保持 190 mAh g 的比容量。此外，CoMoO@NC 负极与 NaV(PO) 正极匹配组装成全电池，在 100 次循环后实现了 152 mAh g 的可逆容量，在 1 A g 的电流密度下容量保持率为 75%，突出了其在 SIBs 中的实际应用。
