A team of researchers led by an engineer at the University of Colorado Boulder has discovered the underlying mechanism behind battery degradation, which could help develop better batteries for electric vehicles and energy storage technologies. Published in the journal Science, the findings could lead to longer-lasting batteries that would accelerate the transition to clean energy. Lithium-ion batteries, the most common type of rechargeable batteries, have been a focus for engineers looking to design batteries without cobalt, a rare mineral linked to environmental and human rights concerns.
Current efforts to replace cobalt in lithium-ion batteries with elements like nickel and magnesium have resulted in batteries with higher rates of self-discharge, reducing their lifespan. The team led by Michael Toney investigated self-discharge, identifying that hydrogen molecules from the battery’s electrolyte move to the cathode and displace lithium ions, weakening the electric current and reducing the battery’s capacity. This understanding could lead to the development of coatings or alternative electrolytes to prevent this process and improve battery performance.
Transportation is a significant source of greenhouse gases in the US, with 28% of emissions coming from the sector in 2021. To reduce emissions, automakers have committed to producing more electric vehicles (EVs) rather than gasoline cars. However, EVs face challenges such as limited driving range, higher production costs, and shorter battery lifespan compared to conventional vehicles. The research by Toney’s team has the potential to address these issues by improving the lifespan and driving range of batteries used in EVs.
Consumers are interested in cars with a large driving range, and reducing cobalt in batteries can potentially increase this range while addressing cost, human rights, and energy justice concerns. By understanding the self-discharge mechanism in batteries, engineers can work on improving battery design to prevent degradation. Coating the cathode with a special material or using a different electrolyte are ways to potentially prevent the self-discharge process and improve battery performance and longevity.
The research conducted by Toney and his team sheds light on the reasons behind battery degradation and provides insights for the battery chemistry community to improve battery design. By informing researchers and engineers about the mechanisms that cause batteries to degrade, the team’s findings could lead to advancements in battery technology that enable longer-lasting, more efficient batteries. Ultimately, this research could contribute to the transition to cleaner energy sources and the widespread adoption of electric vehicles.