(1 of 10)Uncontrollable dendritic behavior and infinite volume expansion in alkali metal anode results in the severe safety hazards and short lifespan for high-energy batteries. Constructing a stable host with superior Na/Li-philic properties is a prerequisite for commercialization. Here, it is demonstrated that the small Gibbs free energy change in the reaction between metal oxide (Co 3 O 4 , SnO 2 , and CuO) and alkali metal is key for metal infusion. The as-prepared hierarchical Co 3 O 4 nanofiber-carbon sheet (CS) skeleton shows improved wettability toward molten Li/Na. The 3D carbon sheet serves as a primary framework, offering adequate lithium nucleation sites and sufficient electrolyte/electrode contact for fast charge transfer. The secondary framework of Co/Li 2 O nanofibers provides physical confinement of deposited Li and further redistributes the Li + flux on each carbon fiber, which is verified by COMSOL Multiphysics simulations. Due to the uniform deposition behavior and near-zero volume change, modified symmetrical Li/Li cells can operate under an ultrahigh current density of 20 mA cm −2 for more than 120 cycles. When paired with LiFePO 4 cathodes, the Li/Co-CS cell shows low polarization and 88.4% capacity retention after 200 cycles under 2 C. Convincing improvement can also be observed in Na/Co-CS symmetrical cells applying NaClO 4 -based electrolyte. These results illustrate a significant improvement in developing safe and stable alkali metal batteries.

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The industrial application of lithium metal anode requires less side reaction between active lithium and electrolyte, which demands the sustainability of the electrolyte‐induced solid‐electrolyte interface. Here, through a new diluted lithium difluoro(oxalato)borate‐based (LiDFOB) high concentration electrolyte system, it is found that the oxidation behavior of aggregated LiDFOB salt has a great impact on solid‐electrolyte interphase (SEI) formation and Li reversibility. Under the operation window of Cu/LiNi0.8Co0.1Mn0.1O2 full cells (rather than Li/Cu configuration), a polyether/coordinated borate containing solid‐electrolyte interphase with inner Li2O crystalline can be observed with the increasing concentration of salt, which can be ascribed to the reaction between aggregated electron‐deficient borate species and electron‐rich alkoxide SEI components. The high Li reversibility (99.34%) and near‐theoretical lithium deposition enable the stable cycling of LiNi0.8Co0.1Mn0.1O2/Li cells (N/P < 2, 350 Wh kg−1) under high cutoff voltage condition of 4.6 V and lean electrolyte condition (E/C ≈ 3.2 g Ah−1).

Solvents are widely used in chemical processes. The use of efficient model‐based solvent selection techniques is an option worth considering for rapid identification of candidates with better economic, environment and human health properties. In this paper, an optimization‐based MLAC‐CAMD framework is established for solvent design, where a novel machine learning‐based atom contribution method is developed to predict molecular surface charge density profiles (σ‐profiles). In this method, weighted atom‐centered symmetry functions are associated with atomic σ‐profiles using a high‐dimensional neural network model, successfully leading to a higher prediction accuracy in molecular σ‐profiles and better isomer identifications compared with group contribution methods. The new method is integrated with the computer‐aided molecular design technique by formulating and solving a mixed‐integer nonlinear programming model, where model complexities are managed with a decomposition‐based strategy. Finally, two case studies involving crystallization and reaction are presented to highlight the wide applicability and effectiveness of the MLAC‐CAMD framework.