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The catalyst‐reconstruction makes it challenging to clarify the practical active sites and unveil the actual reaction mechanism during the CO2 electroreduction reaction (CO2RR). However, currently the impact of the electrolyte microenvironment in which the electrolyte is in contact with the catalyst is overlooked and might induce a chemical evolution, thus confusing the reconstruction process and mechanism. In this work, the carbonate adsorption properties of metal oxides were investigated, and the mechanism of how the electrolyte carbonate affect the chemical evolution of catalysts were discussed. Notably, Bi2O3 with weak carbonate adsorption underwent a chemical reconstruction to form the Bi2O2CO3/Bi2O3 heterostructure. Furthermore, in situ and ex situ characterizations unveiled the formation mechanism of the heterostructure. The in situ formed Bi2O2CO3/Bi2O3 heterostructure with strong electron interaction served as the highly active structure for CO2RR, achieving a formate Faradaic efficiency of 98.1 % at −0.8 Vvs RHE. Theoretical calculations demonstrate that the significantly tuned p‐orbit electrons of the Bi sites in Bi2O2CO3/Bi2O3 optimized the adsorption of the intermediate and lowered the energy barrier for the formation of *OCHO. This work elucidates the mechanism of electrolyte microenvironment for affecting catalyst reconstruction, which contributes to the understanding of reconstruction process and clarification of the actual catalytic structure. [ABSTRACT FROM AUTHOR]

With more renewable energy developed to satisfy the human need in the energy crisis, electricity storage is critical in power utilization and storage. Due to its high safety, high nature reserve, and high energy density, the zinc‐based battery is drawing increasing attention. Together with the expansion of human activities, the low‐temperature battery is developed to satisfy the power demand in extreme environments, and as a critical component, electrolytes shall have a low freezing point and satisfying electrochemical properties in cold conditions. In this review, the development of low‐temperature electrolytes for zinc‐based batteries will be comprehensively introduced. First, the failure mechanism of zinc‐based battery at low temperature will be illustrated. Second, five main types of low‐temperature electrolytes will be introduced in detail. Finally, the regulation of electrolyte/electrode surface at low temperature will be discussed. This review aims to provide a guideline for low‐temperature electrolyte design from the perspective of molecular behavior regulation. [ABSTRACT FROM AUTHOR]

The advent of wearable electronics has strongly stimulated advanced research into the exploration of flexible zinc−air batteries (ZABs) with high theoretical energy density, high inherent safety, and low cost. However, the half‐open battery structure and the high concentration of alkaline aqueous environment pose great challenges on the electrolyte retention capability and the zinc anode stability. Herein, a starch‐based superabsorbent hydrogel polymer electrolyte (SSHPE) with high ionic conductivity, electrolyte absorption and retention capabilities, strong alkaline resistance and high zinc anode stability has been designed and applied in ZABs. Experimental and calculational analyses probe into the root of the superiority of SSHPEs, confirming the significance of the carboxyl functional groups along their polymer chains. These features endow the as‐fabricated ZAB a long cycle life of 300 h, much longer than that with commonly used poly(vinyl alcohol)‐based electrolyte. [ABSTRACT FROM AUTHOR]

Mg‐air batteries are a promising new generation of batteries because they can operate in neutral electrolytes that are safe and nontoxic. However, the high corrosion and low utilization of Mg anodes in Mg‐air batteries result in low specific capacity and severe self‐discharge. In this study, an Mg(OTf)2‐based aqueous electrolyte is developed, which addresses these issues by reducing the contact of the Mg anode with water molecules from the hydrophobic −CF3 groups and forming an MgF2 protective layer. The assembled Mg‐air batteries exhibit specific capacities of up to 1920 mAh g−1Mg (87.32 % utilization based on the Mg anode). In addition, the resting time of the corresponding Mg‐air batteries was 123 times longer than that of Mg‐air batteries with pure NaCl electrolytes under the same conditions. [ABSTRACT FROM AUTHOR]

The development of flexible zinc–air battery (ZAB) is highly desirable in achieving superior and stable electrochemical/mechanical properties. Herein, we developed a Zn‐coated foam anode with three‐dimensional (3D) architecture, obtained by electroplating Zn on Cu foam substrate. The compact outer surface and sufficient amount of metallic Zn could be controlled accurately by selecting appropriate porous substrate and electroplating time on Cu foam. Moreover, adding tetraethylammonium hydroxide (TEAOH) to conventional polyvinyl alcohol (PVA)–KOH hydrogel electrolyte effectively improved the water retention of the semi‐solid electrolyte with stable ionic conductivity. The electrolyte precursor fluid was poured on the uneven outer surface of Zn‐coated foam anode and then frozen crosslinked to increase contact between the 3D anode and the electrolyte. A flexible semi‐solid‐state ZAB based on the 3D Zn‐coated foam anode and the hydrogel electrolyte was assembled and exhibited good discharge performance, high energy density (586.5 Wh kgZn−1) and long cycling life. Benefiting from the flexibility of all components, the resultant ZAB performed stable charge and discharge under bending conditions, indicating its promising potential application for flexible and portable energy storage devices. [ABSTRACT FROM AUTHOR]

Keywords: characterization methods; electrolytes; in situ; lithium-ion batteries; silicon-based anodes The development of characterization methods is anticipated to greatly promote the upgrade of high-performance lithium-ion batteries (LIB) based on silicon (Si)-based anodes. Characterization methods, electrolytes, in situ, lithium-ion batteries, silicon-based anodes. [Extracted from the article]

With the remarkably large theoretical specific capacity of silicon (Si), Si‐based rechargeable lithium‐ion batteries (LIBs) have attracted great interest, as they are expected to meet the growing demand for large‐scale energy storage devices, electric vehicles, and portable electronic devices with high energy density. However, the Si‐based LIB faces great challenges due to the cyclic volume changes induced by Si, which lead to considerable capacity fading. To facilitate the use of high‐performance LIBs enabled by Si‐based anodes, understanding the fading mechanism is necessary. In this regard, various advanced characterization methods have been developed to reveal the fading mechanism and to develop a modification strategy associated with compositional and structural evolution. In this review, the general understanding of the fading mechanism and the technical specifications of Si‐based LIBs are discussed. The recent progress in advanced characterization methods for Si‐based LIBs is summarized with respect to the achievements in compositional and structural interpretation. Several possible future research directions for Si‐based LIBs and the expected development trends in relevant characterization methods are also discussed. [ABSTRACT FROM AUTHOR]

Flexible Zn‐based batteries are emerging candidates for wearable electronics owing to the natural merits of zinc, such as environmental friendliness and low cost. In article number 1802605 by Cheng Zhong, Jun Lu, and co‐workers, the challenges of developing flexible Li‐ion batteries are presented. Thereafter, a brief overview of recent progress in the development of flexible Zn‐based rechargeable batteries from the perspective of energy density, rechargeability, flexible electrolytes, and some other issues that remain to be addressed, are highlighted. [ABSTRACT FROM AUTHOR]

Review: 507 refs. [ABSTRACT FROM AUTHOR]