Non-Destructive Method Regenerates LiCoO2 into High-Energy Density Cathode

A research group from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, under the direction of Prof. Yunxia Zhang, developed a solid-phase sintering strategy to enable direct conversion of the degraded LiCoO₂ (D-LCO) into the high energy density cathode materials.

The research was published in the journal Advanced Energy Materials.

To mitigate resource scarcity, lessen environmental pollution, and fulfill the needs for high-energy-density cathode materials, it is crucial to research efficient regeneration and upcycling strategies in light of the impending influx of lithium-ion batteries that have reached the end of their useful lives.

In this study, a straightforward, non-constructive solid-phase sintering method was suggested to regenerate the D-LCO cathode that had degraded and even enhance its stability at high voltages.

“It's like killing three birds with one stone,” noted Prof. Zhang, pointing to the one-pot solid-phase sintering method’s simultaneous integration of lithium supplementation, Li₂SO₄ coating, Mn doping in Co sites, along with N and S doping in Li-O plates.

In addition to having a high specific discharge capacity of 188.2 mAh/g at 0.2 C, the upcycled cathode outperformed its newly commercialized counterpart in terms of cycling performance, retaining 92.5% of its capacity after 100 cycles at 0.5 C and having excellent rate capability at a high cut-off voltage of 4.5 V.

Various used LCO cathode materials from different manufacturers or with different Li/Co molar ratios could be successfully upgraded into high-performance lithium-ion batteries, demonstrating the method's universality and viability.

Our study provides meaningful guidance for the up-cycling of D-LCO into high energy density batteries with long-term cycling stability, it can also be extended to upgrade other degraded cathode materials into high performance lithium-ion batteries.

Yunxia Zhang, Professor, Hefei Institutes of Physical Science, Chinese Academy of Sciences

Journal Reference

Liu, Z., et al. (2023). Upcycling of Degraded LiCoO₂ Cathodes into High‐Performance Lithium‐Ion Batteries via a Three‐In‐One Strategy. Advanced Energy Materials. doi.org/10.1002/aenm.202302058.

Source: https://english.cas.cn