Sheng Tiandu, Nie Haiying, Xie Yiman, Wang Lihua, Li Jian
School of Materials Science and Engineering, Central South University, Hunan, 410083, P. R. China.
College of Mechanical Engineering, Hunan Institute of Science and Technology, Yueyang, 414006, P. R. China.
Small. 2025 Aug 22:e07895. doi: 10.1002/smll.202507895.
High-entropy oxides represent a paradigm shift in sodium-ion battery cathodes by utilizing entropy-driven structural stabilization to address the intrinsic challenges of lattice strain and sluggish ion kinetics. However, conventional high-entropy oxides face challenges in synthesis complexity and insufficient mechanistic insights into strain-kinetics coupling. Here, a high-entropy O3-type layered oxide, NaNiCoFeMnZnCuTiO (NNCFMZCT), is proposed featuring seven transition metals in a single crystallographic site, to synergistically optimize Na⁺ diffusion and structural resilience. Density functional theory calculations reveal that configurational disorder mitigates anisotropic lattice contraction during O/P phase transitions, while X-ray photoelectron spectroscopy and in situ X-ray diffraction confirm stable TMO₆ octahedra and suppressed irreversible phase transitions. The NNCFMZCT cathode delivers a high reversible capacity (>130 mAh g at 10 mA g), exceptional cycling stability (82.9% retention over 300 cycles at 500 mA g), and superior rate capability (>110 mAh g at 1000 mA g) within 2.0-4.0 V. When paired with commercial hard carbon in ampere-hour-level cylindrical cells, the full cell achieves 84% capacity retention after 200 cycles. This work demonstrates scalable viability for grid storage by establishing a universal strain-kinetics coupling strategy, which advances the rational design of entropy-stabilized cathodes for sustainable energy systems.
高熵氧化物通过利用熵驱动的结构稳定性来应对晶格应变和离子动力学迟缓等内在挑战，在钠离子电池阴极方面代表了一种范式转变。然而，传统的高熵氧化物在合成复杂性以及对应变 - 动力学耦合的机理认识不足方面面临挑战。在此，提出了一种高熵O3型层状氧化物NaNiCoFeMnZnCuTiO（NNCFMZCT），其在单个晶体位点具有七种过渡金属，以协同优化Na⁺扩散和结构弹性。密度泛函理论计算表明，构型无序减轻了O/P相变过程中的各向异性晶格收缩，而X射线光电子能谱和原位X射线衍射证实了稳定的TMO₆八面体和抑制的不可逆相变。NNCFMZCT阴极在2.0 - 4.0 V范围内具有高可逆容量（10 mA g时>130 mAh g）、出色的循环稳定性（500 mA g下300次循环后保留82.9%）和优异的倍率性能（100 mA g时>110 mAh g）。当与商业硬碳在安时级圆柱形电池中配对时，全电池在200次循环后实现84%的容量保持率。这项工作通过建立一种通用的应变 - 动力学耦合策略，证明了用于电网储能的可扩展可行性，这推动了用于可持续能源系统的熵稳定阴极的合理设计。
