Vanadium nitride nanoparticles embedded in carbon matrix with pseudocapacitive behavior for high performance lithium‐ion capacitors
Jinhui Zhang, Ziyang Chen, Tiezhu Xu, Liufeng Ai, Yinghong Xu, Xiaogang Zhang, Laifa Shen
Abstract
Abstract Lithium‐ion capacitors (LICs) have attracted wide attention due to their potential of achieving merits of high‐power output as well as high energy density. However, the key issue of kinetics mismatch between anode and cathode hinders the electrochemical performance of LICs. Therefore, a vanadium nitride composite with nanoparticles embedded in carbon matrix (VN‐C) was prepared as an efficiently pseudocapacitive anode material with high electronic conductivity and fast Li‐ion diffusion rate. The VN‐C composites were synthesized through one‐step ammonia heating treatment at different temperatures among which the sample annealed at 600 °C exhibits high specific capacity (513 mAh·g −1 at 0.1 A·g −1 ), outstanding rate performance (~ 300 mAh·g −1 at 10 A·g −1 ), and excellent cyclic steadiness (negligible capacity decay over 2000 cycles) in half‐cell devices. A high‐performance lithium‐ion capacitor device was also fabricated by using VN‐C‐600 as the anode and activated carbon as the cathode, delivering a maximum energy density of 112.6 Wh·kg −1 and an extreme power density of 10 kW·kg −1 .