Covalent Selenium Embedded in Hierarchical Carbon Nanofibers for Ultra-High Areal Capacity Li-Se Batteries

• Published in: iScience Vol. 23; no. 3; p. 100919
• Main Authors: Zhou, Jian, Chen, Maoxin, Wang, Tao, Li, Shengyang, Zhang, Qiusheng, Zhang, Meng, Xu, Hanjiao, Liu, Jialing, Liang, Junfei, Zhu, Jian, Duan, Xiangfeng
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 27.03.2020; Elsevier
• Subjects: Energy Storage; Materials Characterization Techniques; Nanostructure; Energy Storage; Nanostructure; Materials Characterization Techniques
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2020.100919

Lithium selenium (Li-Se) batteries have attracted increasing interest for its high theoretical volumetric capacities up to 3,253 Ah L−1. However, current studies are largely limited to electrodes with rather low mass loading and low areal capacity, resulting in low volumetric performance. Herein, we report a design of covalent selenium embedded in hierarchical nitrogen-doped carbon nanofibers (CSe@HNCNFs) for ultra-high areal capacity Li-Se batteries. The CSe@HNCNFs provide excellent ion and electron transport performance, whereas effectively retard polyselenides diffusion during cycling. We show that the Li-Se battery with mass loading of 1.87 mg cm−2 displays a specific capacity of 762 mAh g−1 after 2,500 cycles, with almost no capacity fading. Furthermore, by increasing the mass loading to 37.31 mg cm−2, ultra-high areal capacities of 7.30 mAh cm−2 is achieved, which greatly exceeds those reported previously for Li-Se batteries. [Display omitted] •The CSe@HNCNFs were used as flexible and free-standing cathode for Li-Se battery•The CSe@HNCNFs effectively retard polyselenides diffusion during cycling•The CSe@HNCNFs delivered high areal capacity of 7.30 mAh cm−2•The CSe@HNCNFs displayed excellent cyclic stability and rate performance Energy Storage; Materials Characterization Techniques; Nanostructure