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A Redox Couple Strategy Enables Long-Cycling Li- and Mn-Rich Layered Oxide Cathodes by Suppressing Oxygen Release

Journal Article


Abstract


  • Li- and Mn-rich layered oxides (LMROs) are considered the most promising cathode candidates for next-generation high-energy lithium-ion batteries. The poor cycling stability and fast voltage fading resulting from oxygen release during charging, however, severely hinders their practical application. Herein, a strategy of introducing an additional redox couple is proposed to eliminate the persistent problem of oxygen release. As a proof of concept, the cycling stability of Li1.2Ni0.13Co0.13Mn0.54O2, which is a typical LMRO cathode, is substantially enhanced with the help of the S2−/SO32− redox couple, and the capacity shows no decay with a retention of 100% after 700 cycles at 1C, far superior to the bare counterpart (61.7%). The surface peroxide ions (O22−) are readily chemically reduced back to immobile O2− by S2− during charging, accompanied by the formation of SO32−, which plays a critical role in stabilizing the oxygen lattice and eventually inhibiting the release of oxygen. More importantly, the S2− ions are regenerated during the following discharging process and participate in the chemical redox reaction again. The findings shed light on a potential direction to tackle the poor cycling stability of high-energy anion-redox cathode materials for rechargeable metal-ion batteries.

Publication Date


  • 2022

Citation


  • Shao, Q., Gao, P., Yan, C., Gao, M., Du, W., Chen, J., . . . Pan, H. (2022). A Redox Couple Strategy Enables Long-Cycling Li- and Mn-Rich Layered Oxide Cathodes by Suppressing Oxygen Release. Advanced Materials, 34(14). doi:10.1002/adma.202108543

Scopus Eid


  • 2-s2.0-85125183738

Web Of Science Accession Number


Volume


  • 34

Issue


  • 14

Abstract


  • Li- and Mn-rich layered oxides (LMROs) are considered the most promising cathode candidates for next-generation high-energy lithium-ion batteries. The poor cycling stability and fast voltage fading resulting from oxygen release during charging, however, severely hinders their practical application. Herein, a strategy of introducing an additional redox couple is proposed to eliminate the persistent problem of oxygen release. As a proof of concept, the cycling stability of Li1.2Ni0.13Co0.13Mn0.54O2, which is a typical LMRO cathode, is substantially enhanced with the help of the S2−/SO32− redox couple, and the capacity shows no decay with a retention of 100% after 700 cycles at 1C, far superior to the bare counterpart (61.7%). The surface peroxide ions (O22−) are readily chemically reduced back to immobile O2− by S2− during charging, accompanied by the formation of SO32−, which plays a critical role in stabilizing the oxygen lattice and eventually inhibiting the release of oxygen. More importantly, the S2− ions are regenerated during the following discharging process and participate in the chemical redox reaction again. The findings shed light on a potential direction to tackle the poor cycling stability of high-energy anion-redox cathode materials for rechargeable metal-ion batteries.

Publication Date


  • 2022

Citation


  • Shao, Q., Gao, P., Yan, C., Gao, M., Du, W., Chen, J., . . . Pan, H. (2022). A Redox Couple Strategy Enables Long-Cycling Li- and Mn-Rich Layered Oxide Cathodes by Suppressing Oxygen Release. Advanced Materials, 34(14). doi:10.1002/adma.202108543

Scopus Eid


  • 2-s2.0-85125183738

Web Of Science Accession Number


Volume


  • 34

Issue


  • 14