A spray-on coating developed by Professor Junjie Niu, materials science & engineering, and his research team has improved the energy density of lithium-metal batteries by 20 to 30 percent 鈥搘hile also reducing the fire risk that has long limited their commercial use. The results, recently , could accelerate the development of next-generation rechargeable batteries.
鈥淭he results surpassed our expectations,鈥� Niu said. 鈥淥ur coating offers a dual benefit 鈥揵etter performance and better safety.鈥�
Niu鈥檚 research focuses on lithium-metal (LM) batteries, a newer type of lithium-based battery that replaces graphite electrodes with solid lithium. LM batteries can hold significantly more energy than traditional lithium-ion batteries, making them attractive for high-demand needs, such as electric vehicles or energy storage for the grid, Niu said.
鈥淲ith the current li-ion batteries, you can drive, let鈥檚 say, 300 miles on a charge,鈥� he said. 鈥淲ith a LM battery, you can double the energy density 鈥� maybe 500 to 600 miles. That鈥檚 even better than a gas-powered vehicle!鈥�
But there’s a catch: LM batteries are notoriously unstable. The problem stems from dendrites 鈥搉eedle-like structures of lithium that form during charging. Dendrites can pierce the battery’s electrolyte, causing short circuits and even fires.
To address this, Niu鈥檚 team developed a spray-on coating that combines MXene compounds 鈥搆nown for high electrical conductivity 鈥� with a large-molecule polymer that stabilizes the battery surface. The polymer helps prevent dendrite formation, while the MXene improves charge transport.
The innovation targets a key challenge that has stalled commercial rollout of lithium-metal batteries, despite their promise and the considerable industry investment.
The research was completed with a grant from the National Science Foundation.