Battery degradation is one of the major challenges for electric vehicles, but researchers at Cornell University have found a different approach to extend the life of lithium-ion batteries.
According to ITNA quoting Techspot, this method, called "direct electrode-to-electrode regeneration" or DEER, instead of fully disassembling the battery and extracting valuable metals, attempts to directly restore worn yet still usable parts of the battery.
One common factor in the decline of lithium-ion battery performance is the formation of a layer called the "solid electrolyte interphase" or SEI on electrode surfaces. A certain amount of this layer is necessary, but as it thickens, electron movement becomes more difficult and the battery's capacity decreases.
In the DEER process, spent cells are opened and the electrodes are placed in an electrochemical bath containing a substance called DMI. This process removes the thick, excess portion of the SEI layer without destroying the electrode itself. The regenerated electrodes can then be used to build new battery cells.
Researchers' experiments showed that regenerated cells can recover up to 95 percent of their original capacity. Their rate of capacity fade after regeneration was also lower. Treated batteries lost about 0.042 percent of their capacity per cycle, while that figure for worn, untreated batteries was 0.072 percent. This advantage was maintained for about 800 cycles.
This technology could be highly significant for electric vehicle batteries, because batteries are typically removed from vehicles when their capacity falls to around 70 to 80 percent of original capacity, while some of their components are still usable.
However, DEER is not suitable for all degraded batteries, and in cases such as structural cracking, severe lithium loss, or mechanical damage, conventional recycling will still be necessary. Also, the battery must be opened prior to the process. Cornell's estimate suggests the cost of this method can be about $15.25 per kilogram, compared with $26.31 for some common recycling methods.