• Title, Summary, Keyword: Cathode-Electrolyte Interphases

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Effect of Sulfate-based Cathode-Electrolyte Interphases on Electrochemical Performance of Ni-rich Cathode Material

  • Chae, Bum-Jin;Song, Hye Ji;Mun, Junyoung;Yim, Taeeun
    • Journal of Electrochemical Science and Technology
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    • v.11 no.4
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    • pp.361-367
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    • 2020
  • Recently, layered nickel-rich cathode materials (NCM) have attracted considerable attention as advanced alternative cathode materials for use in lithium-ion batteries (LIBs). However, their inferior surface stability that gives rise to rapid fading of cycling performance is a significant drawback. This paper proposes a simple and convenient coating method that improves the surface stability of NCM using sulfate-based solvents that create artificial cathode-electrolyte interphases (CEI) on the NCM surface. SOx-based artificial CEI layer is successfully coated on the surface of the NCM through a wet-coating process that uses dimethyl sulfone (DMS) and dimethyl sulfoxide (DMSO) as liquid precursors. It is found that the SOx-based artificial CEI layer is well developed on the surface of NCM with a thickness of a few nanometers, and it does not degrade the layered structure of NCM. In cycling performance tests, cells with DMS- or DMSO-modified NCM811 cathodes exhibited improved specific capacity retention at room temperature as well as at high temperature (DMS-NCM811: 99.4%, DMSO-NCM811: 88.6%, and NCM811: 78.4%), as the SOx-based artificial CEI layer effectively suppresses undesired surface reactions such as electrolyte decomposition.