An international team of researchers has made a significant discovery that could enhance electric vehicle (EV) battery life, allowing EVs to travel farther on a single charge and extending the lifespan of lithium-ion batteries overall.
For years, the phenomenon of battery capacity diminishing over time has been observed in devices like smartphones and electric cars, yet the exact cause was not fully understood.
Led by Professor Michael Toney at the University of Colorado-Boulder, this research offers insights that may lead to the development of better, more durable batteries, with implications for both the EV market and the broader transition to clean energy.
“We are helping to advance lithium-ion batteries by figuring out the molecular level processes involved in their degradation,” explained Professor Toney, the leader of the study.
This breakthrough comes as engineers worldwide have been focusing on improving lithium-ion battery technology while minimizing the use of cobalt. Cobalt is not only costly but also associated with environmental damage and ethical issues in mining. In response, scientists have explored alternatives like nickel and magnesium, but these elements have presented a new challenge: higher rates of “self-discharge.”
This term refers to internal chemical reactions within the battery that gradually reduce stored energy, thereby limiting battery longevity.
One of the significant impacts of self-discharge is on EV batteries, which typically need replacement within 7-10 years. Seeking solutions, Professor Toney and his team set out to understand what drives this self-discharge mechanism.
In a typical lithium-ion battery, energy is produced when lithium ions, which carry a charge, move between the anode (negative electrode) and the cathode (positive electrode) through a conductive substance known as the electrolyte. As these ions move from one electrode to the other, they create an electric current that powers devices. When the battery is recharged, the lithium ions flow back to the anode, theoretically restoring the battery’s capacity.
However, one reason for self-discharge, as previously understood, is that not all lithium ions return to the anode during charging, which results in a gradual reduction of charged ions available to power devices.
The new study, published in Science, builds on this understanding by pinpointing a more precise mechanism at play. Using the Advanced Photon Source, a sophisticated X-ray machine at the U.S. Department of Energy’s Argonne National Laboratory, the research team discovered that hydrogen molecules from the battery’s electrolyte migrate to the cathode and occupy binding sites usually reserved for lithium ions.
This displacement reduces the number of lithium ions able to bind to the cathode, weakening the electric current and causing a gradual decline in the battery’s capacity.
According to Professor Toney, “Some of these low cobalt-containing batteries can potentially provide a higher driving range, but we also need to make sure they don’t fall apart in a short period of time.”
With this new understanding of the self-discharge process, engineers can now explore practical ways to slow or prevent it. One proposed method involves coating the cathode with a material that blocks hydrogen molecules, while another involves experimenting with different electrolyte compositions to limit hydrogen migration.
The implications of this research extend beyond improving battery life for electric vehicles. As Professor Toney noted, “We can inform the battery chemistry community on what needs to be improved (because) having a better battery is very important in shifting our energy infrastructure away from fossil fuels to more renewable energy sources.”
Enhancing battery longevity and performance is a crucial component in advancing renewable energy systems, as it enables more efficient storage of energy generated from sources like solar and wind.
In the context of EVs, batteries with extended life and reduced self-discharge not only mean that vehicles can travel longer distances between charges but also that fewer battery replacements are necessary over a car’s lifespan, thereby lowering both costs and the environmental impact associated with battery disposal.
This discovery marks a step forward in building batteries that can support the clean energy infrastructure of the future, promising to reduce the dependence on fossil fuels and address some of the core challenges in renewable energy storage.
As engineers and chemists continue to build upon these findings, the hope is that future lithium-ion batteries will be able to provide the same or greater energy output with fewer environmental trade-offs and a longer life, significantly accelerating the transition to sustainable energy solutions worldwide.
What are your thoughts? Please comment below and share this news!
True Activist / Report a typo
