Free‐Standing, Foldable V2O3/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 V2 O3 /multichannel carbon nanofibers (V2 O3 /MCCNFs) composites are prepared via electrospinning and subsequent carbonization. Such V2 O3 /MCCNFs electrode delivers a superior capacity of 881.1 mAh g-1 at 0.1 A g-1 after 240 cycles. More importantly, the ultralong lifespan is achieved with a high capacity of 487.8 mAh g-1 even after 5000 cycles at a high current density of 5 A g-1 with only 0.00323% decay rate, which shows the best performance among the reported V2 O3 -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-1 after 500 cycles at 1 A g-1 with 0.094% decay per cycle. The unprecedented performance can be ascribed to synergetic contributions of V2 O3 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.