High Rate Capability and Enhanced Cyclability of Na3V2(PO4)2F3 Cathode by In Situ Coating of Carbon Nanofibers for Sodium‐Ion Battery Applications

• Published in: Chemistry : a European journal Vol. 24; no. 12; pp. 2913 - 2919
• Main Authors: Zhao, Jing, Gao, Yu, Liu, Qiang, Meng, Xing, Chen, Nan, Wang, Chunzhong, Du, Fei, Chen, Gang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 26.02.2018
• Subjects: Batteries; Carbon; Carbon fibers; carbon nanofibers; Cathodes; Chemical vapor deposition; Chemistry; Electrical conductivity; Electrical resistivity; Electrochemical analysis; Electrochemistry; Energy storage; Nanofibers; nanostructures; Sodium; Sodium-ion batteries
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201704131

A facile chemical vapor deposition method is developed for the preparation of carbon nanofiber (CNF) composite Na3V2(PO4)2F3@C as cathodes for sodium‐ion batteries. In all materials under investigation, the optimized composite content, denoted as NVPF@C@CNF‐5, shows excellent sodium storage performance (86.3 % capacity retention over 5000 cycles at 20 C rate) and high rate capability (84.3 mA h g−1 at 50 C). The superior sodium storage performance benefits from the enhanced electrical conductivity of the working electrode after formation of a composite with CNF. Furthermore, the full cell using NVPF@C@CNF‐5 and hard carbon as the cathode and anode, respectively, demonstrates an impressive electrochemical performance, realizing an ultrahigh rate charge/discharge at a current rate of 30 C and long‐term stability over 1000 cycles. This approach is facile and effective, and could be extended to other materials for energy‐storage applications. Good to go: A facile chemical vapor deposition method is proposed for the in situ preparation of Na3V2(PO4)2F3@C nanocomposites with carbon nanofibers as cathode materials for high‐performance sodium‐ion batteries. One of the prepared electrodes exhibits excellent electrochemical performance (see figure), showing both ultrahigh rate capability (84.3 mA h g−1 at 50 C) and ultralong cycling lifespan (86.3 % capacity retention over 5000 cycles at 20 C rate).