capacity of the modified oxide reaches 320 mAh g -1 in the initial cycle, 94.5% of which remains after 100 cycles. More importantly, the average discharge potential drops only by 136 mV in this process. Our findings illustrate the importance of inactivating the surface oxygen in suppressing the cation mixing in the bulk, providing an effective strategy for designing high-performance Li-rich cathode materials.

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The development of lithium metal batteries is hindered by the low Coulombic efficiency and poor cycling stability of the metallic lithium. The introduction of consumptive LiNO3 as an additive can improve the cycling stability, but its low solubility in the carbonate electrolytes makes this strategy impractical for long-term cycling. Herein we propose LiNO3 as a cosalt in the LiPF6–LiNO3 dual-salt electrolyte to enhance the cycling stability of lithium plating/stripping. Competitions among the components and the resultant substitution of NO3 – for PF6 – in the solvation shell facilitate the formation of a Li3N-rich solid electrolyte interphase (SEI) film and suppress the LiPF6 decomposition. The highly Li+ conductive and stable SEI film effectively tailors the lithium nucleation, suppresses the formation of lithium dendrites, and improves the cycling performance. The competitive solvation has profound importance for the design of a complex electrolyte to meet the multiple requirements of secondary lithium batteries.

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Li‐rich layered metal oxides are one type of the most promising cathode materials in lithium‐ion batteries but suffer from severe voltage decay during cycling because of the continuous transition metal (TM) migration into the Li layers. A Li‐rich layered metal oxide Li1.2Ti0.26Ni0.18Co0.18Mn0.18O2 (LTR) is hereby designed, in which some of the Ti4+ cations are intrinsically present in the Li layers. The native Li–Ti cation mixing structure enhances the tolerance for structural distortion and inhibits the migration of the TM ions in the TMO2 slabs during (de)lithiation. Consequently, LTR exhibits a remarkable cycling stability of 97% capacity retention after 182 cycles, and the average discharge potential drops only 90 mV in 100 cycles. In‐depth studies by electron energy loss spectroscopy and aberration‐corrected scanning transmission electron microscopy demonstrate the Li–Ti mixing structure. The charge compensation mechanism is uncovered with X‐ray absorption spectroscopy and explained with the density function theory calculations. These results show the superiority of introducing transition metal ions into the Li layers in reinforcing the structural stability of the Li‐rich layered metal oxides. These findings shed light on a possible path to the development of Li‐rich materials with better potential retention and a longer lifespan.

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Blade bearings, also termed pitch bearings, are joint components of wind turbines, which can slowly pitch blades at desired angles to optimize electrical energy output. The failure of blade bearings can heavily reduce energy production, so blade bearing fault diagnosis is vitally important to prevent costly repair and unexpected failure. However, the main difficulties in diagnosing low-speed blade bearings are that the weak fault vibration signals are masked by many noise disturbances and the effective vibration data is very limited.To address these problems, this paper firstly deals with a naturally damaged large-scale and low-speed blade bearing which was in operation on a wind farm for over 15 years. Two case studies are conducted to collect the vibration data under the manual rotation condition and the motor driving condition. Then, a method called the empirical wavelet thresholding is applied to remove heavy noise and extract weak fault signals.The diagnostic results show that the proposed method can be an effective tool to diagnose naturally damaged large-scale wind turbine blade bearings.

Lithium‐rich layered oxides are promising candidate cathode materials for the Li‐ion batteries with energy densities above 300 Wh kg−1. However, issues such as the voltage hysteresis and decay hinder their commercial applications. Due to the entanglement of the transition metal (TM) migration and the anionic redox upon lithium extraction at high potentials, it is difficult to recognize the origin of these issues in conventional Li‐rich layered oxides. Herein, Li2MoO3 is chosen since prototype material to uncover the reason for the voltage hysteresis as the TM migration and anionic redox can be eliminated below 3.6 V versus Li+/Li in this material. On the basis of comprehensive investigations by neutron powder diffraction, scanning transmission electron microscopy, synchrotron X‐ray absorption spectroscopy, and density functional theory calculations, it is clarified that the ordering–disordering transformation of the Mo3O13 clusters induced by the intralayer Mo migration is responsible for the voltage hysteresis in the first cycle; the hysteresis can take place even without the anionic redox or the interlayer Mo migration. A similar suggestion is drawn for its iso‐structured Li2RuO3 (C2/c). These findings are useful for understanding of the voltage hysteresis in other complicated Li‐rich layered oxides.