Paul Bowen, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign, and Zhang Huigang, a graduate student and postdoctoral researcher at Xindi, wrapped the film into a three-dimensional nanostructure electrode, so that it could obtain a larger effective volume and current. The demonstration results show that the battery using this electrode can charge and discharge quickly in a few seconds, and the efficiency is 100 times that of the battery with block electrode. This means that when it is used in an electric car, the time required for charging it may be the same as that required for refueling at a gas station; More importantly, rapid charging and discharging has no effect on the energy density of the battery (the size of energy stored in a certain space or mass matter is the problem to be solved, how far the electric vehicle can run on a single charge).
Bowen said: "This new type of fast charging and discharging battery can be used in medical equipment, laser and military fields in addition to the automotive field."
Scientists first coat a tiny sphere on a surface, then tightly wrap the sphere into a grid-like structure, and the gap between the sphere and the periphery of the sphere is filled with metal; Then melting the sphere to obtain a sponge-like three-dimensional bracket; Then the surface of the three-dimensional scaffold is etched by electrolysis to enlarge the micropores in the sponge structure and make an open frame structure. Finally, an active material film is coated on the frame.
The researchers pointed out: "As a result, we got an electrode structure with excellent performance, which has little connection with each other, so lithium ions can move quickly;" The active material film can also make lithium ions diffuse rapidly; At the same time, metal materials make it more conductive. "
Bowen said: "The latest research has nothing to do with any specific battery type, but a new battery design paradigm, which uses three-dimensional structure to enhance the performance of batteries."
This research was supported by the US Army Research Laboratory and the US Department of Energy.