Rapid‐charging niobium–tungsten oxide Nb14W3O44 (NbWO) anodes with a Wadsley–Roth crystallographic shear (WRCS) structure possess 3D interconnected open tunnels. However, the anisotropic Li+ diffusion paths lead to a high lithium‐diffusion barrier of hooping between window sites across edge‐shared octahedrons, as the rate‐limiting step of hooping. To improve the rate capability of NbWO, doping it with low‐valent cations (with valences lower than W6+) to reduce the high lithium‐diffusion barrier is proposed. Electron energy loss spectroscopy reveals that low‐valent V5+, V4+, Tb4+, and Ce4+ tend to distribute on the crystallographic shear plane under electrostatic repulsion forces. The reduction in steric hindrance resulting from the increased long bond length ratio of doped edge‐shared octahedrons, coupled with coordination environment modification of [LiO5] on the crystallographic shear plane due to the low energy level of V5+, enhances Li+ diffusion kinetics and cyclic stability. V5+‐ and Tb4+‐doped NbWOs achieve rate capacities of 83 and 63 mAh g−1, at 200 C (1C = 0.178 Ag−1) and retain 75.42% and 86.79% of their capacities, respectively, after 3700 cycles at 20 C. Thus, the proposed doping strategy is promising for preparing WRCS‐type niobium‐based oxides for ultrafast lithium storage.

中文翻译：

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通过低价阳离子掺杂减少超高功率锂离子电池在 Wadsley-Roth 晶体剪切平面上的锂扩散势垒


具有 Wadsley-Roth 晶体剪切 （WRCS） 结构的快速充电铌-氧化钨 Nb14W3O44 （NbWO） 阳极具有 3D 互连的开放隧道。然而，各向异性的 Li+ 扩散路径导致跨边共享八面体的窗口位点之间的高锂扩散屏障，即环状加速的限速步骤。为了提高 NbWO 的倍率能力，建议用低价阳离子（化合价低于 W6+）掺杂它以减少高锂扩散势垒。电子能量损失谱显示，在静电排斥力的作用下，低价 V5+、V4+、Tb4+ 和 Ce4+ 倾向于分布在晶体剪切面上。由于掺杂边共享八面体的长键长度比增加而减少空间位阻，再加上由于 V5+ 的低能级，[LiO5] 在晶体剪切平面上的配位环境改变，增强了 Li+ 扩散动力学和循环稳定性。V5 + 和 Tb 4 + 掺杂的 NbWO 在 200 C （1C = 0.178 Ag - 1） 下达到 83 和 63 mAh g-1 的倍率容量，并在 20 C 下循环 3700 次后分别保持 75.42% 和 86.79% 的容量。因此，所提出的掺杂策略有望制备用于超快锂存储的 WRCS 型铌基氧化物。