UCLA

Energy storage technologies have emerged as a critical component in the sustainable development of the global energy landscape. Aqueous energy storage systems are considered to be a promising solution to reliably store the energy generated from renewable sources and deliver electricity to the grid on demand. From bulk storage to uninterrupted power supply, large-scale energy storage systems of various power capacity and discharge frequency are needed, requiring rational designs of different electrochemical systems. In this work, unconventional high-energy-density supercapacitors and innovative fast-charging batteries are explored. Utilizing a facile laser scribing fabrication approach, earth-abundant, low-cost, electrochemically active vanadium oxides are incorporated onto highly conductive graphene scaffold. Symmetric supercapacitors based on this composite electrode exhibit high energy densities that are close to conventional batteries. Furthermore, with synthetic modifications, the vanadium oxides/graphene composite is applied as the cathode material in a zinc-ion battery, leading to state-of-the-art rate capability and high-rate cycling stability. Moreover, the synthesis and charge storage mechanism of the pseudocapacitive electrode are further investigated in an aqueous hybrid Li-ion battery.