Researchers from Korea's Gyeongsang National University, Dongguk University and Gwangju Institute of Science and Technology have developed a new method to overcome the limitations of zinc ion batteries (ZIBs), which are gaining attention as a next-generation technology.
The team explored graphene-coated stainless steel foil as an alternative current collector. They showed that a graphene coating followed by heat treatment to remove the surface oxides improves the conductivity and corrosion resistance of the material. As a result, the fabricated ZIB exhibited high specific capacities of 1.90 and 0.91 mAh cm−2 at current densities of 0.3 and 2.0 C, respectively, and demonstrated a remarkable long cycle life with a capacity retention of 88.7% for up to 1500 cycles at a current density of 1.0 C, despite a high electrode loading of 13.27 mg cm−2.
Zinc ion batteries are relatively low cost and have a lower risk of explosion compared to lithium ion batteries, which makes them noteworthy for next-generation large-capacity energy storage systems (ESS) or renewable energy sectors. However, there are drawbacks such as rapid performance degradation during repetitive charge and discharge processes, and corrosion due to water-based electrolytes, leading to a shorter battery lifespan.
To resolve these issues, the research team developed this new technology, that applies graphene thinly and uniformly to the surface of a 'current collector,' which is a thin metal plate that transmits current. In particular, following the 'roll-to-roll' method of continuously moving the metal plate while coating the surface, it was possible to secure the electrical properties and durability of the material with a simple process of heat treatment at 400 degrees.
Professor Ahn Geun-hyeong noted, "This technology is an alternative that can surpass the limitations of existing lithium ion batteries in the energy storage sector," adding, "It will also greatly contribute to reducing energy expenses and enhancing supply chain stability as a sustainable energy technology."
This innovation enhances the electrochemical performance and cycling stability, thereby advancing large-scale ZIBs as a safe, scalable, and high-performance solution.
