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Direct recycling methods offer a non‐destructive way to regenerate degraded cathode material. The materials to be recycled in the industry typically constitute a mixture of various cathode materials extracted from a wide variety of retired lithium‐ion batteries. Bridging the gap, a direct recycling method using a low‐temperature sintering process is reported. The degraded cathode mixture of LMO (LiMn2O4) and NMC (LiNiCoMnO2) extracted from retired LIBs was successfully regenerated by the proposed method with a low sintering temperature of 300°C for 4 h. Advanced characterization tools were utilized to validate the full recovery of the crystal structure in the degraded cathode mixture. After regeneration, LMO/NMC cathode mixture shows an initial capacity of 144.0 mAh g−1and a capacity retention of 95.1% at 0.5 C for 250 cycles. The regenerated cathode mixture also shows a capacity of 83 mAh g−1at 2 C, which is slightly higher compared to the pristine material. As a result of the direct recycling process, the electrochemical performance of degraded cathode mixture is recovered to the same level as the pristine material. Life‐cycle assessment results emphasized a 90.4% reduction in energy consumption and a 51% reduction in PM2.5 emissions for lithium‐ion battery packs using a direct recycled cathode mixture compared to the pristine material.
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Ambient‐Pressure Relithiation of Degraded Li x Ni 0.5 Co 0.2 Mn 0.3 O 2 (0 x < 1) via Eutectic Solutions for Direct Regeneration of Lithium‐Ion Battery Cathodes
Abstract With the rapid growth of the lithium‐ion battery (LIBs) market, recycling and re‐use of end‐of‐life LIBs to reclaim lithium (Li) and transition metal (TM) resources (e.g., Co, Ni), as well as eliminating pollution from disposal of waste batteries, has become an urgent task. Here, for the first time the ambient‐pressure relithiation of degraded LiNi0.5Co0.2Mn0.3O2(NCM523) cathodes via eutectic Li+molten‐salt solutions is successfully demonstrated. Combining such a low‐temperature relithiation process with a well‐designed thermal annealing step, NCM523 cathode particles with significant Li loss (≈40%) and capacity degradation (≈50%) can be successfully regenerated to achieve their original composition and crystal structures, leading to effective recovery of their capacity, cycling stability, and rate capability to the levels of the pristine materials. Advanced characterization tools including atomic resolution electron microscopy imaging and electron energy loss spectroscopy are combined to demonstrate that NCM523's original layered crystal structure is recovered. For the first time, it is shown that layer‐to‐rock salt phase change on the surfaces and subsurfaces of the cathode materials can be reversed if lithium can be incorporated back to the material. The result suggests the great promise of using eutectic Li+molten–salt solutions for ambient‐pressure relithiation to recycle and remanufacture degraded LIB cathode materials.
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- Award ID(s):
- 1805570
- PAR ID:
- 10461406
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Energy Materials
- Volume:
- 9
- Issue:
- 20
- ISSN:
- 1614-6832
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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