Design strategy and research progress of NaTi₂(PO₄)₃ anode/electrolyte interface in aqueous sodium ion batteries

Aqueous sodium-ion batteries (ASIBs) have emerged as promising candidates for large-scale energy storage systems due to their superior safety, cost-effectiveness and environmental friendliness. Among various anode materials, sodium titanium phosphate (NaTi₂(PO₄)₃, NTP) as a NASICON-type compound with its high theoretical capacity, excellent sodium ion conductivity and good structural stability. However, the electrochemical performance of NTP anodes used for ASIBs is significantly hindered by electrode-electrolyte interface instability resulting from the hydrogen evolution reaction (HER), electrode dissolution and unstable solid electrolyte interphase (SEI) in aqueous electrolytes. This review systematically outlines recent advances and technological innovations in the design strategies of NTP anode/electrolyte interfaces to address the previously underexplored interfacial challenges between NTP anode materials and aqueous electrolytes in ASIBs. Subsequently, the proposed solutions, including electrolyte compositional optimization, interfacial coating modification and SEI interface modulation, to the abovementioned issues are correspondingly summarized and discussed. Finally, the development direction and future prospective of NTP anode/electrolyte interface research is further discussed, providing a guidance for the design of high-performance ASIBs.