Exploring Avenues for More Stable Lithium-Metal Batteries

Rechargeable lithium-metal (Li-metal) batteries offer an opportunity to improve on the energy storage density of current lithium-ion batteries and meet the demand of new markets, such as long-range EVs or electric planes. However, they face major performance hurdles related to safety and quickly declining performance. 

Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), in collaboration with their partners in the United States and Germany, highlight a key pathway for solutions in a recent paper published by the journal Energy & Environmental Science.         

The paper examines the origins of instability in lithium-metal batteries, which comes from non-uniform electro-dissolution and -deposition of lithium during discharge and charge processes, respectively. The researchers discuss the current understanding and new insights into the design of lithium metal in liquid electrolytes, and how that could contribute to more stable cycling of lithium metal electrodes. 

“Lithium tends to form dendrites in Li-metal batteries. These not only gradually reduce cell capacity but also can short-circuit the battery, leading to catastrophic failure,” said Robert Kostecki, the lead-author of the review and director of Berkeley Lab’s Energy Storage and Distributed Resources Division. “Through novel experimental and theoretical insights, we need to study the kinetics of lithium metal nucleation, deposition, and stripping on the nanoscale in different electrolyte formulations.”

In a separate study, which Nature Reviews published in August, the researchers gave a comprehensive overview of the spontaneous and operation-induced reactions at the Li-metal/electrolyte interface, taking different perspectives.

A key challenge remains about how to manipulate atoms and corresponding elemental and molecular building blocks to construct compatible structural frameworks of electrodes, electrolytes, and their interfaces for the next generation of Li-metal batteries. Answers to this question, Kostecki said, will lead to new directions for further studies.