4.2 V O3‐Layered Cathodes in Sodium‐Ion Pouch Cells Enabled by an Intermolecular‐Reinforced Ether Electrolyte

Abstract To fulfill the requirements for practical applications, it is urgent to boost the gravimetric energy density of sodium‐ion batteries. An effective way is to increase the charging voltage of O3‐type layered cathodes preferably to 4.2 V versus Na/Na + (V Na ). Nevertheless, it is extremely challenging to achieve stable cycling of the cathodes at such a high cut‐off voltage. Here a novel electrolyte strategy to design an intermolecular‐reinforced electrolyte (IRE) is presented, utilizing meticulously protected ether molecules, which facilitates stable high‐voltage cycling of the commercially viable NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM). While the NFM with the IRE exhibits a high specific capacity of ≈158 mAh…

• NK
  National Key Research and Development Program of China

  Award: 2022YFB3807800