# Bioinspired Injection Therapy for Spent LiFePO4 Batteries: A Non-Invasive Strategy for Capacity Regeneration and Longevity Enhancement

## TL;DR

A new injection therapy using iodine chemistry helps restore capacity and extend the life of used LiFePO4 batteries without disassembling them.

## Contribution

A non-invasive, bioinspired injection strategy using iodine redox chemistry for LiFePO4 battery regeneration is introduced.

## Key findings

- Regenerated LiFePO4 cells show ~7% capacity recovery and extended cycle life beyond 300 cycles.
- The method outperforms conventional recycling with fast charge transfer and superior cyclic stability.

## Abstract

An effective and facile injection strategy based on iodine redox chemistry is proposed to restore lost lithium component in spent LiFePO4 battery.In-situ spectroscopic characterization is conducted to unveil the underlying redox mechanism of iodine-mediated lithium reactivation, elucidating its impact on both the cathode and anode.Regenerated LiFePO4 cells exhibit ~ 7% capacity recovery, fast charge transfer behavior, and extended cycle life beyond 300 cycles at 1C, outperforming conventional direct recycling methods while maintaining superior cyclic stability.

An effective and facile injection strategy based on iodine redox chemistry is proposed to restore lost lithium component in spent LiFePO4 battery.

In-situ spectroscopic characterization is conducted to unveil the underlying redox mechanism of iodine-mediated lithium reactivation, elucidating its impact on both the cathode and anode.

Regenerated LiFePO4 cells exhibit ~ 7% capacity recovery, fast charge transfer behavior, and extended cycle life beyond 300 cycles at 1C, outperforming conventional direct recycling methods while maintaining superior cyclic stability.

The online version contains supplementary material available at 10.1007/s40820-026-02091-1.

The widespread deployment of lithium iron phosphate (LiFePO4, LFP) batteries has intensified the imperative to address the disposal challenges associated with retired LFP batteries, given their rapidly growing volumes. However, existing regeneration techniques remain constrained by their inherent complexity, high energy demands, and limited scalability, posing significant barriers to achieving efficient and economically viable solutions. Herein, inspired by medical injection therapy, a novel, non-invasive strategy for direct capacity rejuvenation is proposed by injecting recovery reagents into spent LFP batteries, circumventing the need for disassembly. This innovative approach leverages the I3−/I− redox couple to activate residual/dead lithium on the graphite anode and selectively re-engineer the solid electrolyte interphase (SEI), preserving its functional components while optimizing interfacial dynamics. The restored lithium from the anode serves as an intrinsic source to replenish lithium deficits and rectify Li–Fe antisite defects within the degraded LFP cathode. The resulting regenerated pouch cells demonstrate remarkable recovery of electrochemical capacity, accompanied by superior kinetics performance and significantly extended cycle life. This pioneering strategy not only delivers an energy-efficient and cost-effective pathway for LFP battery regeneration but also holds transformative potential to redefine sustainable practices in lithium-ion battery reuse, thereby advancing their practical applications and prolonging their service life.

The online version contains supplementary material available at 10.1007/s40820-026-02091-1.