Researchers at the University of Science and Technology of China, in collaboration with other institutions, have developed a new electrolyte design that could significantly extend the lifespan of lithium-metal batteries. This innovation, detailed in a recent study published in Nature Energy, could pave the way for more efficient and longer-lasting energy storage solutions, potentially doubling the range of electric vehicles compared to those powered by today’s lithium-ion batteries.
Lithium-metal batteries are seen as the future of energy storage due to their high energy density, theoretically exceeding 500 Wh/kg—more than double that of conventional lithium-ion batteries. However, the short lifespan of lithium-metal batteries, typically around 50 cycles, has hindered their practical application. The new electrolyte design addresses this limitation by stabilizing both the anode-electrolyte and cathode-electrolyte interfaces, which are prone to degradation during battery operation.
The key to this breakthrough lies in the electrolyte’s unique solvation structure, described as a “compact ion-pair aggregate” (CIPA). Unlike traditional electrolytes, which feature small aggregates and separate ion pairs, the CIPA electrolyte comprises densely packed lithium-anion ion pairs. This structure leads to the formation of a thin, stable solid-electrolyte interphase (SEI) on the lithium-metal anode, preventing the growth of dendrites and reducing the ongoing degradation of the electrolyte.
Initial tests of a 500 Wh/kg lithium-metal pouch cell using the new electrolyte showed promising results, with the cell retaining 91% of its energy after 130 cycles. The research team, led by Prof. Shuhong Jiao, is now working to further extend the cycle life of these cells beyond 1,000 cycles and is exploring even higher energy densities, aiming for 600 Wh/kg with 100-200 cycles.
This novel electrolyte design could represent a significant step forward in the development of next-generation batteries, enabling the deployment of lithium-metal batteries in a wide range of applications, from electric vehicles to portable electronics.
