Self-healing batteries promise longer life and range of electric vehicles

To get better, longer batteries for electric cars, EU-funded researchers are developing technology that enables batteries to quickly detect damage and repair.

go through Anthony King

The battery is one of the biggest speed bumps on roads using large electric vehicles (EVs). But what if they can not only last longer, but also fix themselves? That’s driving researchers, such as Johannes Ziegler and Liu Sufu, who are working to make this reality.

EV sales in Europe rose 20% in February compared to the same month in 2024. Electric vehicles are crucial to enable our transportation and reduce planetary polishing carbon emissions, but their journey is not without challenges.

Most electric cars rely on lithium-ion batteries, similar to those found in our phones, but larger and more complex. Electric vehicle batteries contain dozens of kilograms of valuable metals – lithium, nickel and copper – that must last for more than a decade, matching the life expectancy of the EV.

To address this challenge, a team of researchers gathered under an EU-funded program called Phoenix to develop batteries that can be self-healed. Their goal is to extend battery life, make it safer and reduce the need for new battery metals.

“The idea is to increase battery life and reduce the carbon footprint, because the same battery can repair itself, so overall it requires less resources,” said Ziegler, materials scientist at Fraunhofer.

In 2023, the EU identified 34 materials as key, including battery metals such as lithium, nickel, copper and cobalt.

The Phoenix Project is named after the Mythical Bird, which rises from its own ashes, a suitable symbol for the rebirth and renewal that researchers hope to achieve in battery technology.

The bet is high. EU legislation requires all new cars and vans sold from 2035 to generate zero emissions. The goal is to significantly reduce greenhouse gas emissions in the transportation sector.

To this end, electric cars need better batteries.

Sensors and triggers

Anyone who owns a smartphone will be frustrated by the battery: a few years later, their lifetimes have fallen. The same problem plagued EVS, just on a larger scale.

This happens because a part of the battery will repeatedly charge and discharge over time, so this happens.

Scientists from Belgium, Germany, Italy, Spain and Switzerland are collaborating on designing sensors to detect changes within lithium-ion batteries and trigger the battery’s self-healing if needed.

The goal is to double the lifespan of a battery and the lifespan of an electric vehicle.

Today, the Battery Management System (BMS) – the Battery’s Brain – monitors the battery’s voltage and temperature to ensure it does not overheat and cause safety issues.

“Currently, the general temperature, voltage and current felt is very limited. In addition to providing an estimate of the availability of residual energy, it ensures safety,” said Yves Stauffer, an engineer at the Swiss Center for Electronics and Microscopic Technology (CSEM), an innovation center that develops disruptive technologies. Stauffer leads BMS research.

The Phoenix team’s goal is to develop further by introducing advanced sensors and triggers. Some of them will detect when the battery expands, others will produce heat maps, and some will observe dangerous gases such as hydrogen or carbon monoxide.

All of these sensors will provide an early warning system for battery health.

Healing is activated when the battery’s brain decides that it needs repair. For example, this could mean squeezing the battery back to shape, or applying targeted heat to trigger an internal self-healing mechanism.

“Under heat treatment, some unique chemical bonds will rebound,” said CSEM battery chemist Suare, who also works in Phoenix.

Another self-healing method uses magnetic fields to break the dendrites – branched metal structures formed on the battery electrodes during charging and can lead to short circuits and failures.

Size is important

Phoenix researchers also aim to increase the range of electric vehicles and reduce the size of the battery.

“We are working on developing next-generation batteries with higher energy density,” Sufu said. This means that electric cars need smaller batteries, which will make them lighter and can be charged at one time.

One strategy is to replace graphite with silicon somewhere between metal and non-metal, the material used in pencils.

This is not widely adopted in today’s commercial batteries, partly because of the low stability of silicon and its volume can be expanded by 300% during charging and emissions, Sufu said. In the case of internal silicon, the battery must be able to survive these drastic changes or repair itself.

In March 2025, a batch of new sensor prototypes and triggers were developed and shipped to partners to test the battery bag battery – flexible, lightweight and flat lithium-ion batteries.

But while placing a battery into a sensor is great for providing information about its health, it also adds costs. Therefore, the team focused on determining which technologies provide enough benefits to justify the cost of an electric vehicle.

Either way, it will allow future electric vehicles to last longer and further drive with safer, compact, and less resource-intensive batteries.

Extending battery life will also reduce the carbon footprint of electric vehicles, providing a win-win situation for consumers and the environment.

“It’s exciting to extend the life of the battery and work on an electric car,” Ziegler said. “It’s all about putting parts together.”

The research in this article is funded by the EU’s Horizon Program. The views of respondents do not necessarily reflect the views of the European Commission.

This article was originally published in the European Journal of Research and Innovation.

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