Co <sub>2</sub> B <sub>2</sub> O <sub>5</sub> as an anode material with high capacity for sodium ion batteries
Han Chen, Beibei Xu, Qiushi Ping, Baozhu Wu, Xikai Wu, Qiangqiang Zhuang, Haoli Wang, Baofeng Wang
Abstract
Abstract In this work, a flake‐structured Co 2 B 2 O 5 material was obtained by a simple sol–gel method and researched for use in sodium ion batteries firstly. When serving as anode material for sodium ion batteries, it exhibits the high initial reversible capacity of 466 mAh·g −1 at a current density of 100 mA·g −1 . Through the recombination of carbon nanotubes (CNTs), the composite Co 2 B 2 O 5 /CNTs delivers the initial reversible capacity of 464 mAh·g −1 , and 324 mAh·g −1 is obtained after 60 cycles under the current density of 100 mA·g −1 . When under the current density of 1000 mA·g −1 , a capacity of 236 mAh·g −1 is obtained for Co 2 B 2 O 5 /CNTs while 160 mAh·g −1 for Co 2 B 2 O 5 . Moreover, the sodium storage behavior of Co 2 B 2 O 5 is identified by kinetic analysis. The higher Na + capacitive contribution of Co 2 B 2 O 5 /CNTs could account for the enhanced rate performance. The results indicate that Co 2 B 2 O 5 is a promising anode material for sodium ion batteries.