Ni-rich layered LiNi x Co y Mn 1−x−y O 2 (LNCM) with Ni content over >90% is considered as a promising lithium ion battery (LIB) cathode, attributed by its low cost and high practical capacity. However, Ni-rich LNCM inevitably suffers rapid capacity fading at a high state of charge due to the mechanochemical breakdown; in particular, the microcrack formation has been regarded as one of the main culprits for Ni-rich layered cathode failure. To address these issues, Ni-rich layered cathodes with a textured microstructure are developed by phosphorous and boron doping. Attributed by the textured morphology, both phosphorous-and boron-doped cathodes suppress microcrack formation and show enhanced cycle stability compared to the undoped cathode. However, there exists a meaningful capacity retention difference between the doped cathodes. By adapting the various analysis techniques, it is shown that the boron-doped Ni-rich layered cathode displays better cycle stability not only by its ability to suppress microcracks during cycling but also by its primary particle morphology that is reluctant to oxygen evolution. The present work reveals that not only restraint of particle cracks but also suppression of oxygen release by developing the oxygen stable facets is important for further improvements in state-of-the-art Li ion battery Ni-rich layered cathode materials.

NCM‐based lithium layered oxides (LiNi1–x–yCoxMnyO2) have become prevalent cathode materials in state‐of‐the‐art lithium‐ion batteries. Higher energy densities can be achieved in these materials by systematically increasing the nickel content; however, this approach commonly results in inferior cycle stability. The poor cycle retention of high‐nickel NCM cathodes is generally attributed to chemo‐mechanical degradation (e.g., intergranular microcracks), vulnerability to oxygen‐gas evolution, and the accompanying rocksalt phase formation via cation mixing. Herein, the feasibility of doping strategies is examined to mitigate these issues and effective dopants for high‐nickel NCM cathodes are theoretically identified through a stepwise pruning process based on density functional theory calculations. Specifically, a sequential three‐step screening process is conducted for 38 potential dopants to scrutinize their effectiveness in mitigating chemo‐mechanical lattice stress, oxygen evolution, and cation mixing at charged states. Using this process, promising dopant species are selected rationally and a silicon‐doped LiNi0.92Co0.04Mn0.04O2 cathode is synthesized, which exhibits suppressed lattice expansion/contraction, fewer intergranular microcracks, and reduced rocksalt formation on the surface compared with its undoped counterpart, leading to superior electrochemical performance. Moreover, a comprehensive map of dopants regarding their potential applicability is presented, providing rational guidance for an effective doping strategy for high‐nickel NCM cathodes.

Sodium metal (Na) anodes are considered the most promising anode for high‐energy‐density sodium batteries because of their high capacity and low electrochemical potential. However, Na metal anode undergoes uncontrolled Na dendrite growth, and unstable solid electrolyte interphase layer (SEI) formation during cycling, leading to poor coulombic efficiency, and shorter lifespan. Herein, a series of Na‐ion conductive alloy‐type protective interface (Na‐In, Na‐Bi, Na‐Zn, Na‐Sn) is studied as an artificial SEI layer to address the issues. The hybrid Na‐ion conducting SEI components over the Na‐alloy can facilitate uniform Na deposition by regulating Na‐ion flux with low overpotential. Furthermore, density functional study reveals that the lower surface energy of protective alloys relative to bare Na is the key factor for facilitating facile ion diffusion across the interface. Na metal with interface layer facilitates a highly reversible Na plating/stripping for ≈790 h, higher than pristine Na metal (100 h). The hybrid self‐regulating protective layers exhibit a high mechanical flexibility to promote dendrite free Na plating even at high current density (5 mA cm−2), high capacity (10 mAh cm−2), and good performance with Na3V2(PO4)3 cathode. The current study opens a new insight for designing dendrite Na metal anode for next generation energy storage devices.

This paper presents a pulse radar system to detect drones based on a target fluctuation model, specifically the Swerling target model. Because drones are small atypical objects and are mainly composed of non‐conducting materials, their radar cross‐section value is low and fluctuating. Therefore, determining the target fluctuation model and applying a proper integration method are important. The proposed system is herein experimentally verified and the results are discussed. A prototype design of the pulse radar system is based on radar equations. It adopts three different pulse modes and a coherent pulse integration to ensure a high signal‐to‐noise ratio. Outdoor measurements are performed with a prototype radar system to detect Doppler frequencies from both the drone frame and blades. The results indicate that the drone frame and blades are detected within an instrumental maximum range. Additionally, the results show that the drone's frame and blades are close to the Swerling 3 and 4 target models, respectively. By the analysis of the Swerling target models, proper integration methods for detecting drones are verified and can thus contribute to increasing in detectability.

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