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

EU researchers are developing technologies that allow batteries to detect and repair damage quickly to achieve better, long-term batteries for electric vehicles.

Batteries are one of the biggest speed bumps on the road to adoption of mass electric vehicles (EVs). But what if they could not only last long, but also repair themselves? This is a vision that promotes the visions of Johannes Ziegler and Liu Suhu, who are working to make this happen.

European EV sales increased 20% in February compared to the same month in 2024. EVs are essential to electrifying transportation and reducing the carbon emissions that suck planets, but their journey is not without challenges.

Most EVs rely on lithium-ion batteries similar to cell phone batteries, but are much larger and more complicated. EV batteries contain dozens of kilograms of precious metals (lithium, nickel, copper) and should last for more than 10 years, consistent with the expected lifespan of the EV.

To tackle this challenge, a team of researchers aims to gather under an EU-funded initiative called Phoenix to develop batteries that can heal themselves. Their goal is to extend battery life, make it safer and reduce the need for new battery metals.

Ziegler, a material scientist at the Fraunhofer Institute in Germany, said:

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

The Phoenix Project is named after a mythical bird rising from its own ashes. This is a suitable symbol for regeneration and updates that researchers hope to achieve with battery technology.

And the stakes are high. EU law requires all new cars and vans sold since 2035 to generate zero emissions. The aim is to significantly reduce greenhouse gas emissions from the transportation sector.

To do this, electric vehicles need better batteries.

Sensation and trigger

Anyone who owns a smartphone knows how frustrated they have with batteries. A few years later, the sunk was sank for a lifetime. The same problem plagues EVs on a large scale.

This occurs because the battery is repeatedly charged and drained, resulting in some of the battery being drained over time.

Scientists from Belgium, Germany, Italy, Spain and Switzerland work together to design sensors that detect changes in lithium-ion batteries and trigger battery self-healing if necessary.

The goal is to double the battery life and even double the EV life.

Today, the Battery Management System (BMS) – the brain of the battery – monitors the voltage and temperature of the battery, which does not overheat and causes safety issues.

“Currently, the sensed is very limited in general temperature, voltage and current. In addition to estimating the availability of remaining energy, it also ensures safety,” said Yves Stauffer, an engineer at the Swiss Center for Electronics and Microtechnology (CSEM), an innovation center that develops disruptive technologies. Stauffer leads research on BMS.

The Phoenix team aims to go further by introducing sophisticated sensors and triggers. Some of them detect when the battery expands, others generate heat maps, some monitor dangerous gases such as hydrogen and carbon monoxide.

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

When the battery’s brain determines that repair is necessary, healing is activated. This means, for example, reshaping the battery or applying targeted heat to trigger an internal self-healing mechanism.

“The idea is that under heat treatment, some unique chemical bonds bounce back,” says Suhu, a CSEM battery chemist who also works in Phoenix.

Another self-repair approach uses a magnetic field to divide the dendrites. It branches out metal structures that form on the battery electrodes during charging and can cause short circuits or failures.

Size matters

Phoenix researchers are also looking to increase the range of EVs and reduce battery sizes.

“We are trying to develop next-generation batteries with high energy density,” Sufu said. This means that EVs require smaller batteries, making them lighter and can be driven further on a single charge.

One strategy is to replace graphite, the material used in pencil, with silicon, which is somewhere between metals and non-metals.

This is not widely adopted in today’s commercial batteries as silicon is less stable and its volume can grow to 300% during charging and discharge. If silicon is inside, the battery needs to withstand these dramatic changes or repair itself.

In March 2025, a new batch of sensor prototypes and triggers was developed and shipped to partners for testing in battery pouch cells.

However, loading the sensor into the battery is great for providing information about its health, but it also adds cost. Therefore, the team is focusing on identifying which technology will provide sufficient benefits to justify the cost of an EV.

Whichever approach is prioritized, it will allow safer, more compact, resource-intensive batteries to last longer and drive more secure, more compact and less batteries.

Prolonging battery life reduces the EV’s carbon footprint, providing both consumers and the environment with a favorable advantage.

“It’s exciting to extend the life of the battery and work on EVs,” says Ziegler. “It’s all about putting together the parts.”