A new aqueous energy storage device can be fully charged in a mere 20 seconds – and it could be cheaper than today’s lithium batteries. Korea Advanced Institute of Science and Technology (KAIST) and Kangwon National University scientists developed the device, which is safe, environmentally friendly, and suitable for portable electronics.
Aqueous storage devices are less flammable than today’s lithium batteries, and could be cheaper too, according to ScienceAlert, but limitations have held scientists back. Cells comprising a battery transfer electrons between two materials, but aqueous solutions limit voltage range between the points, according to ScienceAlert. But scientists at institutions in South Korea, according to KAIST, “came up with new structures and materials to facilitate rapid speed in energy exchange on the surfaces of the electrodes and minimize the energy loss between the two electrodes.” They described their strategy for high-performance aqueous hybrid capacitors in the journal Advanced Energy Materials in January. ScienceAlert said hybrid capacitors like this one are basically a mixture of capacitor and battery.
Graphene to the rescue again: the scientists utilized graphene-based polymer chain materials for anodes. Graphene’s web-like structure afforded a high surface area, enabling higher capacitance, according to the institute. Metal oxide nanoparticles served as cathode materials. KAIST said, “This method realized higher energy density and faster energy exchange while minimizing energy loss.”
The device they developed can charge up in 20 to 30 seconds via low-power charging systems like flexible solar cells or USB switching chargers. It boasts a power density 100 times greater than conventional aqueous batteries. And it can sustain capacity for more than 100,000 charges, according to ScienceAlert.
KAIST professor Jeung Ku Kang said in the statement, “This eco-friendly technology can be easily manufactured and is highly applicable. In particular, its high capacity and high stability, compared to existing technologies, could contribute to the commercialization of aqueous capacitors.”