Tea as the holy grail: New hope for used batteries

The number of old lithium-ion batteries is steadily increasing, particularly due to the increasing popularity of electric cars. Lithium iron phosphate cathodes (LiFePO₄) were previously considered difficult to recycle because they contain hardly any valuable metals. Conventional processes such as chemical decomposition or melting are energy-intensive and only yield raw materials, not functional electrodes.

Innovative approach: Tea polyphenols as repair agents

As described in a study paper published via Advanced Materials, researchers from Hefei, Shenzhen and Suzhou are focusing on direct regeneration of batteries by using polyphenols from tea leaves as "electron donors", restoring iron ions back to a functional state and repairing defects in the crystal lattice. Aluminum and phosphate sources complement the method by closing gaps in damaged surfaces and forming new conductive layers that create fast channels for ions and electrons, which is crucial in everyday performance.

Performance of regenerated batteries

After 400 charging cycles, the regenerated cathodes retain over 90% of their original capacity. This means that batteries that were previously considered ‘spent’ can be reused in electric cars or stationary storage systems. It is particularly noteworthy that a natural, inexpensive additive such as tea polyphenol, combined with a targeted repair strategy, enables genuine reuse.

Sustainability meets electromobility

In the long term, this method could enable the industrial implementation of battery regeneration and also be transferred to other battery chemistries. Instead of destroying batteries at the end of their lifespan, they could simply be ‘refreshed’ in the future. This combination of natural substances and chemistry is ecologically, economically, and technologically promising and could profoundly change the future of battery recycling.