Free-Standing, Foldable V O /Multichannel Carbon Nanofibers Electrode for Flexible Li-Ion Batteries with Ultralong Lifespan.

Free-standing electrodes with high energy density and long life are of critical importance to the development of lithium-ion batteries (LIBs) for flexible/wearable electronic devices. Herein, the free-standing and foldable V O /multichannel carbon nanofibers (V O /MCCNFs) composites are prepared via electrospinning and subsequent carbonization. Such V O /MCCNFs electrode delivers a superior capacity of 881.1 mAh g at 0.1 A g after 240 cycles. More importantly, the ultralong lifespan is achieved with a high capacity of 487.8 mAh g even after 5000 cycles at a high current density of 5 A g with only 0.00323% decay rate, which shows the best performance among the reported V O -based anodes and other metal oxides based free-standing anodes. Furthermore, this flexible electrode is further applied to the pouch cell, which exhibits prominent capacity of 348.3 mAh g after 500 cycles at 1 A g with 0.094% decay per cycle. The unprecedented performance can be ascribed to synergetic contributions of V O and multichannel carbon nanofibers, which not only promote the penetration of electrolyte and reduce the transport length of Li , but also increase active material/electrolyte contact area and buffer the volume change. This work paves the way to develop free-standing electrode for flexible/wearable electronic devices with ultralong lifespan.