Perovskite Anode-Based Gel Polymer Electrolytes for High-Performance Sodium-Ion Batteries: Design, Electrochemical Performance and Stability Analysis: A Review

Interest in sodium-ion batteries as an alternative to lithium-ion systems, especially stationary systems, has arisen due to the demand of safe, sustainable and scalable energy storage. The anode material and the composition of the electrolyte are some of the key aspects that define the performance of sodium-ion batteries. This review reports the integration of perovskite-based anode materials with gel polymer electrolytes (GPEs) to enhance the overall efficiency, safety and cyclability of sodium-ion batteries. Perovskite anodes exhibit promising characteristics for sodium storage due to their tunable redox-active sites, structural flexibility and high theoretical capacity. However, their practical application remains limited by challenges such as interfacial degradation, low ionic mobility and phase instability during electrochemical cycling. Compared to conventional liquid electrolytes, GPEs offer improved safety, enhanced thermal stability, superior ionic conductivity and better compatibility with electrode interfaces. This review also systematically examines the electro-chemical behaviour of perovskite anodes, recent advancements in GPE formulations and the synergistic interactions at the electrode–electrolyte interface. It also looks at the constraints, e.g. interfacial mismatches and structural degradation and optimization approaches, e.g. interfacial engineering, nanocomposite design and polymer modification. The study concludes by identifying future research and development directions, emphasizing scalable synthesis methods, environmental sustainability and the techno-economic viability of commercial deployment of sodium-ion batteries.