Alloy Assisted Rechargeable Zinc Oxide Anodes for Aqueous Nickel-Zinc Batteries

In the past few years, the lithium-ion battery (LIB) industry has experienced remarkable growth, along with a significant increase in demand. However, the high cost of raw materials combined with the flammability in LIBs poses challenges to manufacturing and safety. An alternative solution lies in rechargeable aqueous zinc-ion batteries, which are made of more abundant materials (zinc is ~300 times more abundant than lithium), are more environmentally friendly, and a have high specific and volumetric capacity (820 mAh/g and 5845 mAh/cm³). There are drawbacks, however, particularly concerning the parasitic side reactions and irregulated metal deposition of zinc anodes in aqueous solution. Irregulated metal deposition can result in dendrite formation on the electrode, which can pierce through the separator and cause a short circuit, thereby limiting the lifespan of the battery.

In our research, we focus on engineering a nickel cathode and a zinc oxide anode coated with a layer of silver nanoparticles, which is then coated with a layer of ion-sieving carbon nano-shells. Silver is a zincophilic alloy with a low nucleation barrier and can regulate the deposition of zinc as well as minimizing the dissolution of zinc. The ion-sieving carbon nano-shell layer acts as a physical barrier to further prevent active material dissolution and achieve a higher coulombic efficiency.