RESUMO
Aqueous Zn batteries are promising for large-scale energy storage but are plagued by the lack of high-performance cathode materials that enable high specific capacity, ultrafast charging, and outstanding cycling stability. Here, a laser-scribed nano-vanadium oxide (LNVO) cathode is designed that can simultaneously achieve these properties. The material stores charge through Faradaic redox reactions on/near the surface at fast rates owing to the small grain size of vanadium oxide and interpenetrating 3D graphene network, displaying a surface-controlled capacity contribution (90%-98%). Multiple characterization techniques unambiguously reveal that zinc and hydronium ions co-insert with minimal lattice change upon cycling. It is demonstrated that a high specific capacity of 553 mAh g-1 is achieved at 0.1 A g-1, and an impressive 264 mAh g-1 capacity is retained at 100 A g-1 within 10 s, showing excellent rate capability. The LNVO/Zn can also reach >90% capacity retention after 3000 cycles at a high rate of 30 A g-1, as well as achieving both high energy (369 Wh kg-1) and power densities (56306 W kg-1). Moreover, the LNVO cathode retains its excellent cycling performance when integrated into quasi-solid-state pouch cells, further demonstrating mechanical stability and its potential for practical application in wearable and grid-scale applications.
