Bio-Template Synthesis of VO@Carbonized Dictyophora Composites for Advanced Aqueous Zinc-Ion Batteries.

In terms of new-generation energy-storing devices, aqueous zinc-ion batteries (AZIBs) are becoming the prime candidates because of their inexpensive nature, inherent safety, environmental benignity and abundant resources. Nevertheless, due to a restrained selection of cathodes, AZIBs often perform unsatisfactorily under long-life cycling and high-rate conditions. Consequently, we propose a facile evaporation-induced self-assembly technique for preparing VO@carbonized dictyophora (VO@CD) composites, utilizing economical and easily available biomass dictyophora as carbon sources and NHVO as metal sources. When assembled in AZIBs, the VO@CD exhibits a high initial discharge capacity of 281.9 mAh g at 50 mA g. The discharge capacity is still up to 151.9 mAh g after 1000 cycles at 1 A g, showing excellent long-cycle durability. The extraordinary high electrochemical effectiveness of VO@CD could be mainly attributed to the formation of porous carbonized dictyophora frame. The formed porous carbon skeleton can ensure efficient electron transport and prevent VO from losing electrical contact due to volume changes caused by Zn intercalation/deintercalation. The strategy of metal-oxide-filled carbonized biomass material may provide insights into developing high-performance AZIBs and other potential energy storage devices, with a wide application range.