Finely crafted lanthanum vanadium oxide cathode as durable and flexible quasi-solid state zinc ion battery

Aqueous Zinc ion batteries grant intriguing potential to large-scale energy storage, but they are still plagued by trade-off in high discharge capacity and long cycle life. In this work, such a critical barrier can be well solved by a novel cathode, rare-earth lanthanum orthovanadate (LaVO4). For traditional aqueous cells, the LaVO4 (LVO) cathode delivers a high discharge capacity of 351.8 mAh g(-1) at 0.5 A g(-1), and ultralong cyclic life (93.5% retention after 6500 cycles at 5 A g(-1)). Moreover, the estimated energy density of the Zn//LVO batteries is 316.6 Wh kg(-1) at a power density of 450 W kg(-1). Investigation into the mechanism of the charge storage demonstrates that the capacity contribution of pseudocapacitance behavior is dominant, which explains its excellent rate capability. For flexible quasi-solid-state zinc ion batteries, the LVO@CNT films show impressive rate capability and high bending durability (137.8 mAh g(-1) at 8 A g(-1)). The superior electrochemical performance of LVO suggests its great potential in clean energy.

Automated summary

The novel cathode material, rare-earth lanthanum orthovanadate (LaVO4), effectively addresses the trade-off between high discharge capacity and long cycle life in aqueous zinc ion batteries. It shows impressive rate capability, ultralong cyclic life, and dominant contribution of pseudocapacitance behavior to the capacity.