N-doped carbon encapsulated CoMoO4 nanorods as long-cycle life anode for sodium-ion batteries

作者：Huang, Xiaoqing; Zhang, Wenbiao; Zhou, Chaojin; Yang, Lichun^*; Wang, Hui; Gao, Qingsheng^*; Zhu, Min

来源：Journal of Colloid and Interface Science, 2020, 576: 176-185.

DOI：10.1016/j.jcis.2020.05.017

• Sodium-ion batteries
• Anode materials
• N-doped carbon
• Mixed transition-metal oxides
• Long-cycle life

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 CoMoO4 (CoMoO4@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 CoMoO4. The optimized composite presents rapid reaction kinetics and excellent cycle stability. Even at a high current density of 1 A g(-1), it still shows long-cycle life and maintains specific capacity of 190 mAh g(-1) after 3200 cycles. Furthermore, CoMoO4@NC anode is applied to match with Na3V2(PO4)(3) cathode to assemble full-cells, in which it accomplishes reversible capacity of 152 mAh g(-1) after 100 cycles, with capacity retention of 75% at a current density of 1 A g(-1), highlighting the practical application for SIBs.