The Mn-based Natrium superionic conductor (NASICON)-type materials are promising cathode materials for sodium-ion batteries (SIBs) due to their environmental friendliness and cost-effectiveness. However, the practical application of Mn-based materials is hindered by their poor cycle performance, arising from intrinsic kinetic limitation and negative structural degradation caused byMn. Herein, a Mn-based ternary NASICON-type Na_3.5MnTi_0.5Cr_0.5(PO₄)₃/C (NMTCP-50) is designed featuring multi-metal synergy with enhanced effect from each component, which contributes to breaking through the bottleneck of inferior cycle performance for Mn-based NASICON-type materials. The results of ex-situ X-ray diffraction corroborate that both solid-solution and bi-phase electrochemical reactions are involved in the sodiation/desodiation processes, and the volume variation is only 2.55 %. Galvanostatic intermittent titration technique tests and density functional theory calculations further demonstrate the fast reaction kinetics of the NMTCP-50 electrode. NMTCP-50 can deliver an excellent cycling durability of 75 % after 5000 cycles at 2 A g⁻¹ and a high reversible capacity of 137.6 mAh g⁻¹. The availability of NMTCP-50 has been evaluated by a full cell assembled with hard carbon. This work offers theoretical support for understanding the multi-metal synergistic effect in NASICON materials and provides a blueprint for designing low-cost NASICON cathodes.

锰基钠超离子导体（NASICON）型材料由于其环境友好性和成本效益而成为有前景的钠离子电池（SIB）正极材料。然而，锰基材料的实际应用受到其较差的循环性能的阻碍，这是由于锰本身的动力学限制和负面结构退化造成的。在此，设计了一种锰基三元NASICON型Na _3.5 MnTi _0.5 Cr _0.5 (PO ₄ ) ₃ /C (NMTCP-50)，其特点是多金属协同作用，各组分的效果增强，有助于突破金属材料的瓶颈。 Mn基NASICON型材料的循环性能较差。结果非原位X射线衍射证实固溶体和双相电化学反应都参与了钠化/脱钠过程，且体积变化仅为2.55%。恒电流间歇滴定技术测试和密度泛函理论计算进一步证明了NMTCP-50电极的快速反应动力学。^{NMTCP-50在2 A g -1}下循环5000次后可提供75%的优异循环耐久性和137.6 mAh g ^-1的高可逆容量。NMTCP-50 的可用性已通过硬碳组装的全电池进行了评估。这项工作为理解NASICON材料中的多金属协同效应提供了理论支持，并为设计低成本NASICON阴极提供了蓝图。