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Abstract Aqueous batteries represent a compelling frontier for safe and sustainable large-scale energy storage. However, the narrow electrochemical stability window and complex interfacial side reactions of water fundamentally limit their energy density and cycle life. In biological cells, the highly crowded intracellular environment governs vital biochemical processes by restricting water mobility. Inspired by this natural mechanism, molecular crowding electrolytes (MCE) have been developed to manipulate the hydrogen-bonding network of aqueous electrolytes. This review provides a systematic overview of aqueous lithium-ion, sodium-ion, zinc-ion, iron-metal, aluminum-metal, and proton batteries. By introducing proper crowding agents, MCE effectively sequesters water molecules into localized coordination environments, thereby suppressing water-driven parasitic reactions without relying on extreme salt concentrations. The adoption of MCE could enable next-generation aqueous batteries with high energy density and prolonged cycling stability. 

Abstract Real‐time onboard state monitoring and estimation of a battery over its lifetime is indispensable for the safe and durable operation of battery‐powered devices. In this study, a methodology to predict the entire constant‐current cycling curve with limited input information that can be collected in a short period of time is developed. A total of 10 066 charge curves of LiNiO₂‐based batteries at a constant C‐rate are collected. With the combination of a feature extraction step and a multiple linear regression step, the method can accurately predict an entire battery charge curve with an error of < 2% using only 10% of the charge curve as the input information. The method is further validated across other battery chemistries (LiCoO₂‐based) using open‐access datasets. The prediction error of the charge curves for the LiCoO₂‐based battery is around 2% with only 5% of the charge curve as the input information, indicating the generalization of the developed methodology for predicting battery cycling curves. The developed method paves the way for fast onboard health status monitoring and estimation for batteries during practical applications. 

Microwave radiation (MWR), a type of electromagnetic excitation source, reduces the synthesis temperature and processing time for chemical reactions compared to traditional synthesis methods. Recently, we demonstrated that MWR can engineer ceramics with different crystal phases compared to traditional methods [Journal of Materials Chemistry A 5, 35 (2017)]. In this study, we further apply the MWR-assisted technique to improve the electrochemical performance of LiCoO2 cathodes by engineering TiO2 and ZrO2 ceramic coatings. Electrochemical tests suggest that the TiO2 coating improves the rate capability of the LiCoO2 electrode. Both TiO2 and ZrO2 coatings improve the high-voltage (4.5 V) cycling stability of LiCoO2. The capacity remaining is improved from 52.8 to 84.4% and 81.9% by the TiO2 coating and the ZrO2 coating, respectively, after 40 cycles. We compare these results with existing studies that apply traditional methods to engineer TiO2/ZrO2 on LiCoO2, and find that the MWR-assisted method shows better performance improvement. X-ray photoelectron spectroscopy measurements suggest that the improved cycling stability arises from the formation of metal fluorides that protect the electrode from side reactions with electrolytes. This mechanism is further supported by the reduced Co dissolution from TiO2/ZrO2-coated LiCoO2 electrode after cycling. This study provides a new toolbox facilitating the integration of many delicate, low melting point materials like polymers into battery electrodes.