Polymer-induced solid–electrolyte interphase on hard carbon enabling 5C fast-charging practical sodium-ion pouch cell

ABSTRACT Achieving <15 min fast-charging technology for long-life sodium-ion batteries (SIBs) remains a formidable challenge, primarily due to parasitic reactions and unstable solid–electrolyte interphase (SEI) at the hard carbon (HC) interface. Here we develop a universal polymer-induced SEI strategy that enables an Ah-level SIB pouch cell to achieve <10 min fast-charging capability. We design a <4.0 nm functionalized polymer molecular layer, polyethylenesulfonyl fluoride (PESF), coated on the HC surface (PolyHC) to minimize electrolyte decomposition. The PESF with the –SO2F group attached has a powerful polar feature, which simultaneously induces an anion enriched at the PolyHC interface…

• NN
  National Natural Science Foundation of China

  Awards: 225B2302, 22503044, 52372195, 22409084
• NK
  National Key Research and Development Program of China

  Award: 2021YFA1202300