LaVO4 Nanorods Decorated on rGO Conductive Network as High-Performance Cathode Materials for Aqueous Zinc-Ion Batteries

The escalating depletion of fossil fuels and the attendant environmental concerns have spurred the pursuit of advanced energy storage systems. Aqueous zinc-ion batteries (AZIBs) stand out as promising candidates due to their inherent safety, cost-effectiveness, and abundant zinc resources. However, vanadium-based cathodes, a leading class of materials for AZIBs, are plagued by structural instability and inadequate electrical conductivity, which severely hamper their electrochemical performance. In this work, a one-step hydrothermal method was used to fabricate LaVO4/rGO (denoted as LVG) composites, in which La3+ species act as interlayer pillars to suppress the dissolution of active materials, while the conductive rGO network promotes rapid electron migration, collectively leading to improved electrochemical performance. AZIBs assembled with the LVG-2 cathode (LaVO4/rGO composite prepared with an initial GO loading of 80 mg) achieve a high specific capacity of 311 mAh g−1 at 0.2 A g−1, accompanied by a maximum energy density of 249 Wh kg−1 and a peak power density of 4000 W kg−1. The LVG-2 electrode delivers a reversible capacity of 133 mAh g−1 after 1000 cycles at 5 A g−1, with a capacity retention of 62%, owing to the rGO-enhanced conductivity and stable interlayer structure. Furthermore, flexible AZIBs incorporating the LVG-2 cathode exhibit stable performance under repeated bending. In addition, it can successfully power on a humidity meter and a warning light, which can serve as a warning for safe travel on the highway.