Layered sodium manganese-based oxides are highly attractive cathode materials for sodium-ion batteries but suffer from limited initial coulombic efficiency (ICE) and poor structural stability. Herein, a high-entropy biphasic Na_0.7Mn_0.4Ni_0.3Cu_0.1Fe_0.1Ti_0.1O_1.95F_0.1 cathode material is reported to exhibit remarkable ICE, rate capability and cyclability. In-situ structural analysis during the preparation of cathode reveals tunable P2/O3 ratios by changing the sintering temperature. The synthesized high-entropy oxide with a P2/O3 ratio of 23:77 (wt%) delivers a high ICE of 97.6%, a considerable discharge capacity of 86.7 mAh g⁻¹ at current density of 800 mA g⁻¹, and respectable capacity retention in a wide temperature range from -40 to 50 °C. Additionally, full cell coupling Na_0.7Mn_0.4Ni_0.3Cu_0.1Fe_0.1Ti_0.1O_1.95F_0.1 and hard carbon exhibits an energy density of 268.3 Wh kg⁻¹ at power density of 1172 W Kg⁻¹ based on the mass of cathode. Combined experimental and computational investigations suggest that the as-prepared Na_0.7Mn_0.4Ni_0.3Cu_0.1Fe_0.1Ti_0.1O_1.95F_0.1 cathode favors reversible structural evolution, fast Na⁺ diffusion kinetics, and low energy barriers due to the unique P2/O3 biphasic structure and high-entropy effect. This study brings an in-depth insight into the design and preparation of high-entropy P2/O3 biphasic cathode to build advanced sodium-ion batteries.

层状钠锰基氧化物是钠离子电池极具吸引力的阴极材料，但初始库仑效率 (ICE) 有限且结构稳定性差。在此，据报道，高熵双相 Na _0.7 Mn _0.4 Ni _0.3 Cu _0.1 Fe _0.1 Ti _0.1 O _1.95 F _0.1正极材料表现出显着的 ICE、倍率性能和循环性能。就地阴极制备过程中的结构分析揭示了通过改变烧结温度可调节的 P2/O3 比率。^{合成的 P2/O3 比为 23:77 (wt%) 的高熵氧化物可提供 97.6% 的高 ICE，在 800 mA g -1}的电流密度下可提供 86.7 mAh g ^-1的相当大的放电容量，并且可观在 -40 至 50 °C 的宽温度范围内保持容量。此外，全电池耦合 Na _0.7 Mn _0.4 Ni _0.3 Cu _0.1 Fe _0.1 Ti _0.1 O _1.95 F _0.1和硬碳在 1172 W Kg 的功率密度下表现出 268.3 Wh kg ^-1的能量密度^-1基于阴极的质量。结合实验和计算研究表明，由于独特的 P2/O3，所制备的 Na _0.7 Mn _0.4 Ni _0.3 Cu _0.1 Fe _0.1 Ti _0.1 O _1.95 F _0.1阴极有利于可逆结构演变、快速 Na ⁺扩散动力学和低能垒双相结构和高熵效应。本研究深入探讨了高熵 P2/O3 双相阴极的设计和制备，以构建先进的钠离子电池。