Injecting chemicals helps 'revive' old batteries

Scientists have developed a method that significantly restores a battery's original capacity after degradation due to many charge-discharge cycles .

Currently, lithium-ion batteries are the most popular type of rechargeable battery, providing energy for vehicles and everyday items such as electric vehicles, laptops, and smartphones. But over time, they lose their ability to hold a charge, become less efficient and less reliable. The reason is that they lose charged particles, or ions, that help store and release energy inside the battery.

Lithium batteries used for electric cars. (Photo: South_agency/iStock)

A team of experts at Toyota's Central Research and Development Laboratory in Japan found a way to supplement these ions and significantly restore the battery's original capacity, Interesting Engineering reported on March 10. New research published in the journal Joule.

Specifically, they inject a special substance called recovery reagent into the battery. This substance triggers a chemical reaction that produces more electrons and lithium ions. These are two types of charged particles that help batteries store energy. By adding these particles, the research team was able to reverse the battery's degradation process and restore 80% of its original capacity. The restored battery can maintain performance for 100 charge-discharge cycles.

The research team tested the new method on many different types of batteries, large and small, including those used for cars. "The effect has been verified not only with small-sized batteries in the laboratory but also with large batteries used in cars ," said Nobuhiro Ogihara, the study's lead scientist.

The new method could extend the life of lithium-ion batteries , allowing them to be reused in electric vehicles or other devices instead of being thrown away or going through a complicated disassembly and recycling process. This helps save costs and resources, while protecting the environment because lithium-ion batteries contain rare metals such as cobalt and nickel, which are often mined in unsustainable ways.

However, the new method is not applicable to all types of degraded batteries, but is only effective for batteries that lose ions due to repeated charging and discharging , not for batteries with structural damage or other forms of degradation. Additionally, a method of accurately diagnosing battery status is needed to decide whether they are suitable for chemical injection.

According to Jacqueline Edge, an expert in battery degradation at Imperial College London, long-term studies are needed to understand more about the potential side effects and safety of injecting chemicals into batteries. The team has applied for a patent on the new method, attracting interest and funding from several companies and government agencies.