Vanadium-based compound with large lattice spacing as stable cathode for aqueous zinc-ion battery

Vanadium oxide (VO) cathode with large theoretical capacity has attracted much attention for aqueous zinc-ion batteries (ZIBs). However, VO cathode suffers from poor zinc-ion (Zn2+) diffusion kinetics, hindering the development of ZIBs for practical application. Herein, large lattice spacing vanadium-based compound (L-VO) was designed by the pillar between the V-O layers, in which the lattice spacing has increased from 1.15 nm (VO) to 1.64 nm (L-VO). Owing to the large lattice spacing, the L-VO cathode shows rapid Zn2+ diffusion kinetics, delivering high capacity of 399 mAh/g and stable cycle performance (retention rate of 95 % after 2000 cycles).