Cascading V2O3/N-doped carbon hybrid nanosheets as high-performance cathode materials for aqueous zinc-ion batteries
Yue Niu, Denghui Wang, Yingjie Ma, Linjie Zhi
Abstract
In recent years, especially when there is increasing concern about the safety issue of lithium-ion batteries (LIBs), aqueous Zn-ion batteries (ZIBs) have been getting a lot of attention because of their cost-effectiveness, materials abundance, high safety, and ecological friendliness. Their working voltage and specific capacity are mainly determined by their cathode materials . Vanadium oxides are promising cathode materials for aqueous ZIBs owing to their low cost, abundant resources, and multivalence. However, vanadium oxide cathodes still suffer from unsatisfactory capacity, poor stability, and low electrical conductivity . In this work, cascading V 2 O 3 /nitrogen doped carbon (V 2 O 3 /NC) hybrid nanosheets are prepared for high-performance aqueous ZIBs by pyrolyzing pentyl viologen dibromide (PV) intercalated V 2 O 5 nanosheets . The unique structure features of V 2 O 3 /NC nanosheets , including thin sheet-like morphology, small crystalline V 2 O 3 nanoparticles , and conductive NC layers, endow V 2 O 3 /NC with superior performance compared to most of the reported vanadium oxide cathode materials for aqueous ZIBs. The V 2 O 3 /NC cathode exhibits the discharge capacity of 405 mAh/g at 0.5 A/g, excellent rate capability (159 mAh/g at 20 A/g), and outstanding cycling stability with 90% capacity retention over 4000 cycles at 20 A/g.