NASICON-structured materials with high ionic conductivity, robust structure, and high operation potential have aroused extensive attentions as cathode for sodium-ion batteries (SIBs). However, the poor intrinsic electronic conductivity and low specific capacity are crucial obstacles for practical application of NASICON materials. Herein, a new NASICON-structured Na₃MnTi(PO₄)_2.83F_0.5 (NMTPF-0.5) with the hierarchical and porous structure is synthesized by a simple sol–gel method. The Rietveld refinements and Inductively Coupled Plasma (ICP) chemical analysis confirms the NASICON structure of NMTPF-0.5. The unique structural design significantly enhances rate performance. Meanwhile, the introduction of F^- stimulates electrochemical activities of Mn, and stabilizes crystal structure compared with traditional Na₃MnTi(PO₄)₃. Consequently, the NMTPF-0.5 achieves the high energy density of 511 Wh kg⁻¹ at 0.1C, an outstanding rate performance (364 Wh kg⁻¹ at 10C), and the desirable cycling stabilities exceeding 500 cycles at 10C. The ex-situ XRD reveals the insertion/extraction of Na⁺ through the reversible solid-solution mechanism. Moreover, we statistically analyze how the electrochemical properties and microstructure affected by various F^- substitution amounts. This study explored a novel strategy for designing high capacity and high power-density cathode materials for SIBs via the microstructure and crystal structure optimization.

NASICON结构材料具有高离子电导率、坚固的结构和高操作潜力，作为钠离子电池（SIBs）的正极引起了广泛关注。然而，固有的电子导电性差和比容量低是NASICON材料实际应用的关键障碍。在此，通过简单的溶胶-凝胶法合成了具有分层和多孔结构的新型NASICON结构Na ₃ MnTi(PO ₄ ) _2.83 F _{0.5 (NMTPF-0.5)。}Rietveld 改进和电感耦合等离子体 (ICP) 化学分析证实了 NMTPF-0.5 的 NASICON 结构。独特的结构设计显着提高了倍率性能。^同时，引入 F-与传统的Na ₃ MnTi(PO ₄ ) ₃相比，刺激了Mn的电化学活性，并稳定了晶体结构。因此，NMTPF-0.5 在 0.1C 下实现了 511 Wh kg ^-1的高能量密度、出色的倍率性能（在 10C 下为 364 Wh kg ^-1）以及在 10C 下超过 500 次循环的理想循环稳定性。异位 XRD通过可逆固溶机制揭示了 Na ^{+的插入/脱出。}此外，我们统计分析了各种 F ^-替代量。本研究探索了一种通过微观结构和晶体结构优化设计用于 SIB 的高容量和高功率密度正极材料的新策略。