Surface-dominated storage of heteroatoms-doping hard carbon for sodium-ion batteries

By Qianzheng Jin, Kangli Wang, P. Feng, Zhuchan Zhang, Shijie Cheng, Kai Jiang. 2020

237 citations recorded by the source corpus.

Abstract Though the intercalation mechanism of hard carbon anodes for Na-ion batteries (NIBs) gain decent electrochemical performances, the sluggish diffusion kinetics of Na-ions at low potential present huge challenge to high power applications. To improve the rate capability and cycling stability, especially the performance at high rates, herein, a novel N, S co-doping strategy based on the pseudocapacitive mechanism is developed via one-step synthesis, which endows the hard carbon with excellent rate performances and long-term cycling stability. Moreover, the electrochemical behaviors of N, S co-doping carbon materials outperform those of single heteroatom (N) doping materials, owing to the additional effective covalent S bonds and more defects. The optimized NSC2 (derived from 2:1 mass ratio of thiourea and sodium citric) delivers a high reversible capacity of 280 ​mAh g−1 at 0.05 ​A ​g−1 for 200 cycles and 223 ​mAh g−1 at 1 ​A ​g−1 for 2000 cycles, respectively, and preserves 102 ​mAh g−1 at 10 ​A ​g−1. This work provides a universal co-doping approach on modification of hard carbon materials for high power battery applications.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/b36e1b97261bce9128b2df33be73be000255ab20