Developing microbatteries
In the MPC’s Carl V. Thompson lab, professor of materials science and engineering, Rahul Kini tried building thin film batteries.In an electron sputtering machine, layers of current collector anodes and cathodes (typically titanium or platinum), silicon for the anode, lithium phosphorus oxynitride (LiPON) for the electrolyte, lithium cobalt oxide for the cathode, and a coating of titanium to prevent the LiPON from reacting with oxygen in the air are deposited onto a silicon wafer substrate over the course of several hours.
The thickness of the material is about 1,000 nanometers, or one micron.”What we’re sincerely attempting to accomplish is high energy thickness, high energy limit and reusability,” Kini says. “If you have a lot of energy, great, but even better if it can be used again.
We are attempting to determine:Can this be reused for 50 or 100 cycles?We will have a tremendous voltage and energy capacity if we are able to stack all these thin films.Long-term dependability is really what we’re looking at.