Ultrafast\nSodium–Ion Batteries Based on Vanadium\nOxide and Laser-Scribed Graphene Electrodes

Sodium–ion batteries represent one of the current\nresearch\nfrontiers, owing to their low cost, intrinsic safety, environmental\nfriendliness, and other unique features. Investigations are conducted\ntoward the exploration of advanced electrode materials with exceptional\nenergy/power density, superior rate capability, and ultralong cycling\nlife. Notably, vanadium oxide electrode materials have received great\nattention due to their diversity in chemical compositions and attractive\nelectrochemical properties. In this work, we propose a novel synthetic\nstrategy to create a vanadium oxide laser-scribed graphene (VOLG)\nelectrode as a highly functional anode material for sodium–ion\nbatteries. The designed synthesis combines a fast laser-scribing step\nwith controlled heating to tune the morphology and oxidation state\nof the electrochemically active vanadium oxide species while creating\na highly conductive graphene scaffold. The selective insertion mechanism\nof sodium ions into V<sub>2</sub>O<sub>5</sub> is systematically investigated.\nAs a result, we demonstrate that a high specific capacity of 415 mA\nh g<sup>–1</sup> can be achieved by the VOLG anode in the sodium–ion\nbattery system at 0.2 A g<sup>–1</sup>, and an outstanding\n147 mA h g<sup>–1</sup> capacity can be retained at 20 A g<sup>–1</sup> with a 70 s charge/discharge cycle, showing excellent\nrate capability. The VOLG anode is capable of reaching 87% capacity\nretention after 1000 cycles at a rate of 1 A g<sup>–1</sup>. This innovative strategy provides a pathway to incorporate pseudocapacitive\nelectrodes for improving sodium ion storage systems, enabling a low\ncost, safe, and environmentally friendly operation of large-scale\nenergy storage with promising electrochemical performance.