Recent Advances on High-Entropy Strategies Developed for High-Performance NASICON-type Cathodes for Sodium Ion Batteries: A Mini Review

Abstract

Sodium-ion batteries (SIBs) are promising for grid-scale energy storage and low-speed electric vehicles due to sodium's high earth abundance and low cost, but their commercialization is hindered by sluggish Na⁺ transport kinetics and low output voltages. NASICON-type polyanionic compounds stand out as cathode materials for SIBs owing to their open framework structure, multi-electron redox activity, and excellent thermal stability, yet suffer from low electronic conductivity and insufficient energy density, and the high-entropy strategy—originally developed for alloys and later extended to oxides—has emerged as an effective modification approach to enhance their structural stability, electrochemical performance, and thermal safety through multi-element substitution, this mini-review summarizes the fundamentals of high-entropy materials (including definition, core design principles, and fabrication methods), recent advances in high-entropy NASICON cathodes (encompassing phosphates-based and anion-substituted systems), performance enhancements (e.g., reduced volume variation, improved high-voltage stability, accelerated Na⁺ diffusion kinetics, widened operating temperature range) and underlying mechanisms, as well as current challenges (e.g., element segregation) and future perspectives (rational material design, precise synthesis control, operando characterization techniques), aiming to provide insights for the development of high-performance NASICON cathodes and promote the commercialization of SIBs.