Comprehensive Understanding of High‐Entropy NASICON Cathode Materials for Sodium Ion Batteries

ABSTRACT In response to growing worldwide energy needs, polyanionic compounds have gained increasing attention as highly potential cathode/anode candidates in sodium‐based energy storage systems. These materials exhibit two key advantages: exceptional framework robustness and superior charge‐storage characteristics. Nevertheless, their widespread adoption is hindered by inherent limitations, including poor electronic conductivity and vulnerability to detrimental phase transitions during cycling. High‐entropy polyanionic cathodes present a compelling solution to these challenges by leveraging an entropy‐driven strategy, wherein multiple transition metals or anions are incorporated to achieve high configurational entropy. This approach promotes electronic structure rearrangement, improves conductivity, and mitigates undesirable phase transitions. This review comprehensively examines high‐entropy configuration phosphate‐based NASICON‐type cathodes, evaluating recent research progress and their electronic structure modulation mechanisms. Additionally, it highlights the exceptionally wide‐temperature performance of these materials and underscores the untapped potential of pyrophosphate‐based systems, which remain underexplored. Finally, the review outlines future research directions to advance high‐entropy polyanionic cathodes for next‐generation energy storage applications.