High-entropy materials (HEMs) have emerged as promising frontiers in electrochemical energy storage systems because of their unique compositional versatility and tunable physicochemical properties. By incorporating multiple principal elements with distinct chemical functionalities, HEMs exhibit tailored electronic/ionic configurations, enabling unprecedented structural adaptability and application potential. This review systematically analyzes the fundamental principles underpinning the entropy-driven optimization of the electrochemical performance of battery materials, with a focus on the interplay between compositional disorder and functional enhancements. For the first time, we comprehensively review recent advances in Na superionic conductor (NASICON)-type HEMs spanning cathodes, solid-state electrolytes, and anodes. Through investigations, the profound impacts of high-entropy strategies on critical material parameters, including lattice strain modulation, interfacial stability reinforcement, charge-transfer kinetics optimization, and ion transport pathway regulation, were elucidated. Furthermore, we evaluate the current challenges in high-entropy NASICON-type battery design and propose actionable strategies for advancing next-generation high-entropy battery systems, emphasizing rational compositional screening, entropy-stabilized interface design, and machine learning-assisted property prediction.

Garnet-type Li₇La₃Zr₂O₁₂ (LLZO) is one of the most promising solid-state electrolytes (SSEs). However, the application of LLZO is limited by structural instability, low ionic conductivity, and poor lithium stability. To obtain a garnet-type solid electrolyte with a stable structure and high ionic conductivity, a series of TaCe co-doping cubic Li_6·4La₃ZrTa_0.6CeO₁₂ (LLZTCO, x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, 0.30) electrolytes were successfully synthesized through conventional solid-phase method. The Ta⁵⁺ doping can introduce more lithium vacancies and effectively maintain the stability of the cubic phase. The Ce⁴⁺ with a larger ionic radius is introduced into the lattice to widen the Li⁺ migration bottleneck size, which significantly increased the ionic conductivity to 1.05 × 10⁻³ S/cm. It also shows excellent stability to lithium metal by the optimization of Li⁺ transport channel. Li||LLZTCO||Li symmetric cells can cycle stably for more than 6 000 h at a current density of 0.1 mA/cm² without any surface modifications. The commercialization potential of LLZTCO samples in all solid-state lithium batteries (ASSLBs) is confirmed by the prepared LiFePO₄||LLZTCO||Li cells with a capacity retention rate of 98% after 100 cycles at 0.5C. This new co-doping method presents a practical solution for the realization of high-performance ASSLBs.