A team of Chinese scientists has found an innovative way to revive old lithium batteries using compounds found in tea.
Their breakthrough could make battery recycling cheaper, greener, and far more efficient, offering new hope for tackling the growing problem of retired power batteries.
With the rise of electric vehicles, the use of lithium-ion batteries has skyrocketed. But as these batteries reach the end of their life, they leave behind mountains of waste.
Traditional recycling methods—such as smelting at high temperatures or dissolving materials in acid—are costly, energy-intensive, and often only recover a fraction of the useful materials.
In particular, they struggle to recycle lithium iron phosphate (LiFePO₄) batteries, which are widely used but not considered economically attractive for conventional recycling.
In a new study published in Advanced Materials, researchers from the Institute of Solid State Physics at the Hefei Institutes of Physical Science, Chinese Academy of Sciences, along with colleagues from Tsinghua University’s Shenzhen International Graduate School and Suzhou University of Technology, explored a different approach.
Instead of breaking the batteries down into raw elements, they developed a method to directly “heal” the degraded cathode material and restore its original structure.
The key ingredient was tea polyphenols—natural compounds found in tea leaves that act as powerful electron donors.
By combining these compounds with extra lithium salts, the researchers were able to transform degraded iron phosphate (FePO₄) back into lithium iron phosphate (LiFePO₄).
This process also repaired critical structural defects that usually weaken the battery’s performance, essentially re-opening the channels that allow lithium ions to move quickly during charging and discharging.
To fix another common problem—damage to the surface carbon layer of the particles—the team added an aluminum source during regeneration. This led to the formation of a protective coating made of aluminum phosphate (AlPO₄) and lithium phosphate (Li₃PO₄), which bonded strongly to damaged regions.
This coating created efficient pathways for both electrons and ions, boosting the regenerated battery’s performance. At the same time, small amounts of aluminum entered the crystal structure of the cathode material, stabilizing it and helping to prevent further degradation without sacrificing energy capacity.
The result is a regenerated lithium battery cathode that performs almost like new, with extended service life and stable performance.
Because the process relies on natural, low-cost materials like tea polyphenols and avoids the energy demands of traditional recycling, it could provide a more sustainable way to handle the coming wave of retired electric vehicle batteries.
The researchers say their work not only offers a practical solution for LiFePO₄ recycling but also points the way toward greener strategies for managing the life cycle of all lithium-ion batteries.
Source: Chinese Academy of Sciences.
