Lithium Vanadium Phosphate/Carbon Nanofiber Films as Selfstanding, Binderfree, and Flexible Cathodes for Lithium-Ion Batteries

• Published in: Energy technology (Weinheim, Germany) Germany), 2016-09, Vol.4 (9), p.1047-1052
• Main Authors: Pi, Zhi-chao, Jing, Mao-xiang, Li, Jing-quan, Zhai, Hong-ai, Chen, Li-li, Yao, Shan-shan, Shen, Xiang-qian, Xi, Xiao-ming, Xiao, Ke-song
• Format: Article
• Language: English
• Subjects: batteries; Carbon; Carbon fibers; Cathodes; Composite structures; Electrochemical analysis; Electrochemistry; electrodes; Electron microscopy; Lithium; Lithium-ion batteries; Nanofibers; nanostructures; Phosphates; Rechargeable batteries; Retention capacity; Sintering; Vanadium
• ISSN: 2194-4288; 2194-4296
• DOI: 10.1002/ente.201600056

Flexible lithium vanadium phosphate/carbon nanofiber (i.e., Li3V2(PO4)3/C) were fabricated by an electrospinning process combined with hot‐pressed sintering, and are used in lithium‐ion batteries as selfstanding, binderfree and flexible cathodes. The microstructure and crystalline phase of the as‐prepared films are characterized by scanning electron microscopy, transmission electron microscopy, and X‐ray diffractometry. The electrochemical properties of the Li3V2(PO4)3/C nanofiber films were analyzed by cyclic voltammetry and galvanostatic charge/discharge tests. When the nanofiber precursor was sintered at 850 °C for 20 h, the resulting film displays high flexibility and crystallinity. This selfstanding Li3V2(PO4)3/C film exhibits a superior rate performance even at 20 C and good cycle ability, with a retention capacity of 112 mAh g−1 at a current density of 1 C after 1000 cycles and 71 mAh g−1 at 5 C after 800 cycles. These features are attributed to the special composite structure formed by the Li3V2(PO4)3 and the carbon support, and the 3D long‐range conductive networks. Stand and deliver: Flexible lithium vanadium phosphate/carbon nanofiber (i.e., Li3V2(PO4)3/C) films are fabricated by an electrospinning process followed by hot‐pressed sintering. The technique results in selfstanding, binderfree cathodes for lithium‐ion batteries. The films are highly flexible and exhibit superior rate performances even at 20 C, and good cycle ability, and they remain stable over several hundred cycles.