Zhang Teng, Zhang Long, Zhao Lina, Huang Xiaoxiao, Li Wei, Li Tao, Shen Tong, Sun Shengnan, Hou Yanglong
Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China.
Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKL-MMD), Beijing Innovation Centre for Engineering Science and Advanced Technology (BIC-ESAT), Beijing, 100871, China.
Small. 2020 Nov;16(47):e2005302. doi: 10.1002/smll.202005302. Epub 2020 Nov 2.
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.
具有高能量密度和长寿命的独立式电极对于用于柔性/可穿戴电子设备的锂离子电池（LIB）的发展至关重要。在此，通过静电纺丝和随后的碳化制备了独立且可折叠的VO/多通道碳纳米纤维（VO/MCCNFs）复合材料。这种VO/MCCNFs电极在240次循环后，在0.1 A g的电流密度下具有881.1 mAh g的优异容量。更重要的是，即使在5 A g的高电流密度下循环5000次后，仍实现了487.8 mAh g的高容量超长寿命，衰减率仅为0.00323%，这在已报道的基于VO的负极和其他基于金属氧化物的独立式负极中表现最佳。此外，这种柔性电极进一步应用于软包电池，在1 A g的电流密度下循环500次后，其容量为348.3 mAh g，每次循环衰减0.094%，表现出突出的性能。这种前所未有的性能可归因于VO和多通道碳纳米纤维的协同作用，它们不仅促进了电解质的渗透并缩短了Li的传输长度，还增加了活性材料/电解质的接触面积并缓冲了体积变化。这项工作为开发具有超长寿命的用于柔性/可穿戴电子设备的独立式电极铺平了道路。
