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Evaporation‐driven electricity generators have been proposed to generate electricity by water interacting with nanostructured materials. However, several proposed mechanisms, such as intrinsic gradient of polar functional groups principle and electrokinetic effect perspective, are in wide discrepancy. Here, through the combination of theoretical calculations involving time dimension on material's moisturizing process and experimental analyses, it is revealed the working principle through the water molecule triple roles in driving moisture electric generators (MEGs): 1) intrinsic H2O absorption on the material surface and splitting into hydroxy group and proton due to the polarizability of the material surface determined by the static electric potential of the materials. This process induces the electrochemical potential difference of the materials via the work function changes; 2) freely diffused protons derived from the H2O splitting work as the ions charge carriers; 3) via the hydrogen bond of the water molecules to drive charge carriers diffuse between opposite electrodes, maintaining the internal circuit current flow. It is successfully unveiled that anatase TiO2 based materials for output voltage changes correlated to the domains' work function's difference, tuning by the surface adsorption species (H, Cl, OH) and anisotropic exposed crystal facets of the material. This work unveils MEG's general working principle. [ABSTRACT FROM AUTHOR]

As a new type of secondary ion battery, aqueous zinc‐ion battery has a broad application prospect in the field of large‐scale energy storage due to its characteristics of low cost, high safety, environmental friendliness, and high‐power density. In recent years, manganese dioxide (MnO2)‐based materials have been extensively explored as cathodes for Zn‐ion batteries. Based on the research experiences of our group in the field of aqueous zinc ion batteries and combining with the latest literature of system, we systematically summarize the research progress of Zn−MnO2 batteries. This article first reviews the current research progress and reaction mechanism of Zn−MnO2 batteries, and then respectively expounds the optimization of MnO2 cathode, Zn anodes, and diverse electrolytes and their effects on battery performance. Additionally, primary challenges related to different components and their respective strategies for mitigating them are discussed, with the ultimate objective of offering comprehensive guidance for the design and fabrication of high‐performance Zn−MnO2 batteries. Finally, the future research and development direction of aqueous Zn−MnO2 batteries with high energy density, high safety and long life is envisioned. [ABSTRACT FROM AUTHOR]

Silver‐zinc (Ag–Zn) batteries are a promising battery system for flexible electronics owing to their high safety, high energy density, and stable output voltage. However, poor cycling performance, low areal capacity, and inferior flexibility limit the practical application of Ag–Zn batteries. Herein, we develop a flexible quasi‐solid‐state Ag–Zn battery system with superior performance by using mild electrolyte and binder‐free electrodes. Copper foam current collector is introduced to impede the growth of Zn dendrite, and the structure of Ag cathode is engineered by electrodeposition and chloridization process to improve the areal capacity. This novel battery demonstrates a remarkable cycle retention of 90% for 200 cycles at 3 mA cm−2. More importantly, this binder‐free battery can afford a high capacity of 3.5 mAh cm−2 at 3 mA cm−2, an outstanding power density of 2.42 mW cm−2, and a maximum energy density of 3.4 mWh cm−2. An energy management circuit is adopted to boost the output voltage of a single battery, which can power electronic ink display and Bluetooth temperature and humidity sensor. The developed battery can even operate under the extreme conditions, such as being bent and sealed in solid ice. This work offers a path for designing electrodes and electrolyte toward high‐performance flexible Ag–Zn batteries. [ABSTRACT FROM AUTHOR]