Innovation of Electrolyte and Electrode Materials and Interface Construction Strategies in Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are promising for large-scale energy storage owing to the abundant sodium resources, low cost, and lithium-ion battery (LIB)-analogous working principles, yet their commercialization is hindered by low energy density, insufficient cycling stability and safety concerns, which are essentially attributed to the inadequate optimization of electrolytes, electrode materials and their interfacial behaviors. This paper presents a systematic review of the latest research advances in SIBs from three core perspectives: electrolyte system optimization, electrode material design, and electrode/electrolyte interface engineering. For electrolytes, we elaborate on the optimization strategies of liquid organic, solid-state and aqueous electrolytes; for electrode materials, we summarize the research progress and modification methods of both cathode and anode materials; for interface regulation, we clarify the formation mechanisms, characterization techniques and construction strategies of the electrode/electrolyte interface. By quantitatively comparing the advantages and limitations of different technical approaches, we further propose the prioritized future research directions for SIBs in electrolyte innovation, electrode material design and interface optimization. This work aims to provide theoretical guidance and technical references for the development of high-performance SIBs by systematically sorting out the technical routes of electrolyte–electrode-interface synergy and defining the research focus of subsequent optimization.