A technology has been developed to restore the performance of electrodes from used lithium-ion batteries without dismantling or melting them. Researchers expect the technique can recover battery capacity by up to 95 percent and cut manufacturing costs for refurbished batteries by more than half.

Online media outlet Gigazine reported on Tuesday that a Cornell University research team in the United States developed a technology that restores performance by immersing used lithium-ion battery electrodes in a special electrochemical solution.

The core of the study is regenerating the electrode itself without breaking the battery down to the level of raw materials. The team named the technique DEER, short for Direct Electrode-to-Electrode Regeneration.

Conventional lithium-ion battery recycling generally involves melting batteries at high temperatures or crushing them and then extracting metals such as lithium, nickel and cobalt through chemical processing. While it has the advantage of recovering critical minerals, the electrode structure disappears entirely, requiring refining and reprocessing to make batteries again.

By contrast, the new technique separates the electrodes from used batteries and restores them while they remain attached to the metal current collector. That allows most of the electrode manufacturing process to be skipped, sharply reducing costs and energy use, the report said.

The researchers focused on the SEI (Solid Electrolyte Interphase) layer, one of the main causes of battery performance degradation. The SEI layer forms on the electrode surface during repeated charging and discharging, and if it thickens over time it blocks lithium-ion movement, reducing battery capacity and output.

To address this, the team used a DMI (1,3-dimethyl-2-imidazolidinone) solvent to remove the SEI layer from the surface of degraded electrodes. It then applied a process to restore electrode performance and succeeded in returning them to a reusable state.

Test results were also positive. Refurbished cells made with electrodes that underwent the DEER process recovered up to 95 percent of their initial capacity and maintained stable performance during repeated charge and discharge cycles, it said.

The analysis also found competitiveness on the economics. The team said applying the technology could cut refurbished battery manufacturing costs by up to 56 percent compared with existing recycling processes.

The technique cannot be applied to all used batteries. The research mainly focused on post-use EV batteries with a state of health of about 70 to 80 percent, meaning it cannot restore severely damaged batteries to the level of new products.

The researchers said further work is needed to develop response technologies for other degradation causes, such as lithium loss, alongside industrial-scale demonstration.

The industry is focusing on the study because it presents an approach different from existing used-battery recycling methods. If it becomes possible to repair and reuse batteries while keeping components intact, rather than extracting raw materials to make them again, the economics of the EV battery reuse market could improve significantly.

The team assessed that practical application of a new recycling model that restores used batteries at the component level for reuse, rather than returning them to the materials level, has moved closer.