Liu Xianyu, Ma Liwen, Du Yehong, Lu Qiongqiong, Yang Aikai, Wang Xinyu
School of Chemistry and Chemical Engineering, Lanzhou City University, Lanzhou 730070, China.
Institute of Materials and Technology, Dalian Maritime University, Dalian 116026, China.
Nanomaterials (Basel). 2021 Apr 20;11(4):1054. doi: 10.3390/nano11041054.
Aqueous zinc-ion batteries (ZIBs) with the characteristics of low production costs and good safety have been regarded as ideal candidates for large-scale energy storage applications. However, the nonconductive and non-redox active polymer used as the binder in the traditional preparation of electrodes hinders the exposure of active sites and limits the diffusion of ions, compromising the energy density of the electrode in ZIBs. Herein, we fabricated vanadium pentoxide nanofibers/carbon nanotubes (VO/CNTs) hybrid films as binder-free cathodes for ZIBs. High ionic conductivity and electronic conductivity were enabled in the VO/CNTs film due to the porous structure of the film and the introduction of carbon nanotubes with high electronic conductivity. As a result, the batteries based on the VO/CNTs film exhibited a higher capacity of 390 mAh g at 1 A g, as compared to batteries based on VO (263 mAh g). Even at 5 A g, the battery based on the VO/CNTs film maintained a capacity of 250 mAh g after 2000 cycles with a capacity retention of 94%. In addition, the VO/CNTs film electrode also showed a high energy/power density (e.g., 67 kW kg/267 Wh kg). The capacitance response and rapid diffusion coefficient of Zn (~10 cm s) can explain the excellent rate capability of VO/CNTs. The vanadium pentoxide nanofibers/carbon nanotubes hybrid film as binder-free cathodes showed a high capability and a stable cyclability, demonstrating that it is highly promising for large-scale energy storage applications.
具有低成本和良好安全性特点的水系锌离子电池（ZIBs）被视为大规模储能应用的理想候选者。然而，传统电极制备中用作粘合剂的非导电且无氧化还原活性的聚合物阻碍了活性位点的暴露并限制了离子扩散，降低了ZIBs中电极的能量密度。在此，我们制备了五氧化二钒纳米纤维/碳纳米管（VO/CNTs）复合薄膜作为ZIBs的无粘合剂阴极。由于薄膜的多孔结构以及具有高电子导电性的碳纳米管的引入，VO/CNTs薄膜具有高离子导电性和电子导电性。结果，基于VO/CNTs薄膜的电池在1 A g下表现出390 mAh g的更高容量，相比之下基于VO的电池容量为263 mAh g。即使在5 A g下，基于VO/CNTs薄膜的电池在2000次循环后仍保持250 mAh g的容量，容量保持率为94%。此外，VO/CNTs薄膜电极还显示出高能量/功率密度（例如，67 kW kg/267 Wh kg）。Zn的电容响应和快速扩散系数（~10 cm² s⁻¹）可以解释VO/CNTs优异的倍率性能。五氧化二钒纳米纤维/碳纳米管复合薄膜作为无粘合剂阴极表现出高容量和稳定的循环性能，表明其在大规模储能应用中极具前景。
