context: In summary, we demonstrated the use of a multicomponent electrolyte containing sodium perchlorate, urea, N,N-dimethylformamide (DMF) and water, enabling us to immensely decrease the amount of water, forming a complex solvent sheath and a uniform SEI layer composed of complexes with inorganic salt Na2CO3 and other organic components between the interface of the NTP anode and electrolyte. Such an electrolyte provides a voltage window up to 2.8 V and ensures the feasibility of stable and reversible operation of a NVP/NTP sodium ion battery. This battery exhibits an excellent flat voltage platform of about 1.2 V and achieves 86% capacity retention after 100 cycles at the 10C rate. Simultaneously, a NiHCF//NTP full cell with the MCAE displays 80% capacity retention after 2000 cycles at 2C rate. In addition, this MCAE displays high safety, a wide operating temperature range (−50 °C to 50 °C) and high ionic conductivity because of the roles of urea and DMF additives. And above all, the fluorine-free MCAE makes the battery much safer and more environmentally friendly than the existing battery systems with highly concentrated aqueous electrolytes. Meanwhile, we provide a new perspective that can be expanded to other systems of aqueous sodium-ion full cells, which promotes the application of safe, environmentally friendly and stable AISBs for large-scale energy storage.
answer: sodium perchlorate, urea, N,N-dimethylformamide (DMF) and wate