Mechanistic Insights Into Entropy Regulation in Sodium/Potassium‐Ion Batteries

ABSTRACT Sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) have emerged as significant contenders for large‐scale energy storage technology due to their substantial resource reserves and cost effectiveness. However, their large‐scale development is hindered by several key challenges, including the structural degradation of electrode materials during cycling, slow kinetics, and instability at the electrode–electrolyte interface. Entropy‐regulation strategies, particularly medium‐to‐high‐entropy designs, represent an emerging paradigm in materials design. The integration of multiple components, with the aim of leveraging their synergistic effects, presents a novel approach to address the aforementioned challenges in a systematic manner. It has been demonstrated that, owing to its elevated configurational entropy, this strategy accomplishes two objectives: first, it provides thermodynamic stabilization of the crystal structure, and second, it suppresses undesirable phase transitions. Additionally, it induces kinetic effects that result in slow diffusion, thereby effectively delaying element migration and side reactions. Concurrently, entropy regulation fosters the establishment of a stable interfacial film at the electrode‐electrolyte interface, thereby enhancing interfacial ionic transport efficiency and chemical stability. This paper systematically reviews the mechanistic insights and research progress of entropy‐regulation strategies in cathode materials, anode materials, and interface engineering for SIBs and PIBs, and outlines future directions for this field.