Two substances discharge battery cells from within
In the lab, ferrocene and phenothiazine lowered charged-cell voltage to about 0.1 V. In another test, phenothiazine mobilized deposited lithium.
The key idea
In laboratory tests, two substances brought charged cells’ voltage close to zero. In another test, phenothiazine mobilized deposited lithium.
The study, in plain language
Used lithium-ion batteries can retain residual energy and have deposited lithium, both of which complicate recycling. An external short circuit is not useful for some cells with a broken circuit or electrically isolated lithium. The team tested introducing redox-shuttle solutions to deactivate them from within.
With ferrocene or phenothiazine, charged cells’ open-circuit voltage fell from 4.1 to about 0.1 V. In a separate test, phenothiazine dissolved deposited lithium in prepared cells and returned it to the positive electrode as mobile ions. These were laboratory tests on specific pouch cells, not a test at a recycling plant.
What they found
- The voltage of charged cells fell close to zero with ferrocene or phenothiazine.
- In cells prepared with deposited lithium, phenothiazine dissolved it and returned it to the positive electrode as mobile ions.
- The redox reaction discharges the cell from within without needing an external short circuit.
Something to think about
Even after a device stops working, its battery may retain residual energy. How can a cell’s voltage be lowered before recycling it?
How they studied it
The team introduced ferrocene or phenothiazine solutions into lithium-ion pouch cells and tracked open-circuit voltage over time. In another test, they prepared cells with deposited lithium, added phenothiazine, and examined the electrodes to see if the lithium moved. The article measured voltage, not stored energy. The tests were in a lab and did not validate the process at industrial scale.
What the study cannot show
- Selected cells and materials were tested, not a complete recycling line.
- The study did not show that the process can operate safely at industrial scale.
- It did not evaluate all costs, environmental impacts, or the final quality of recovered material.
The original study
Battery deactivation with redox shuttles for safe and efficient recycling
Source under CC BY 4.0. English adaptation and explanation by PaperFlow, with AI assistance. The text has been reorganized for a general audience; it is not the complete paper and does not imply endorsement by its authors.
One study alone does not represent a field's consensus. Educational content does not replace professional advice. Report a possible error.
