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Aqueous zinc batteries, that demonstrate high safety and low cost, are considered promising candidates for large‐scale energy storage. However, Zn anodes suffer from rapid performance deterioration due to the severe Zn dendrite growth and side reactions. Herein, with a low‐cost ammonium acetate (NH4OAc) additive, a self‐regulated Zn/electrolyte interface is built to address these problems. The NH4+ induces a dynamic electrostatic shielding layer around the abrupt Zn protuberance to make the Zn deposition uniform, and the OAc− acts as an interfacial pH buffer to suppress the proton‐induced side reactions and the precipitation of insoluble by‐products. As a result, in the electrolyte with the NH4OAc additive, Zn anodes exhibit a long cycling stability of 3500 h at 1 mA cm−2, an impressive cumulative areal capacity of 5000 mAh cm−2 at 10 mA cm−2, and a high Coulombic efficiency of ≈99.7%. A prototype full cell coupled with a NH4V4O10 cathode performs much better in terms of capacity retention than the additive‐free case. The findings pave the way for developing practical Zn batteries. [ABSTRACT FROM AUTHOR]

Sluggish evolution of lithium ions' solvation sheath induces large charge‐transfer barriers and high ion diffusion barriers through the passivation layer, resulting in undesirable lithium dendrite formation and capacity loss of lithium batteries, especially at low temperatures. Here, an ion‐dipole strategy by regulating the fluorination degree of solvating agents is proposed to accelerate the evolution of the Li+ solvation sheath. Ethylene carbonate (EC)‐based fluorinated derivatives, fluoroethylene carbonate (FEC) and di‐fluoro ethylene carbonate (DFEC) are used as the solvating agents for a high dielectric constant. As the increase of the fluorination degree from EC to FEC and DFEC, the Li+‐dipole interaction strength gradually decreases from 1.90 to 1.66 and 1.44 eV, respectively. Consequently, the DFEC‐based electrolyte displays six times faster ion desolvation rate than that of a non‐fluorinated EC‐based electrolyte at −20 °C. Furthermore, LiNi0.8Co0.1Mn0.1O2||lithium cells in a DFEC‐based electrolyte retain 91% original capacity after 300 cycles at 25 °C, and 51% room‐temperature capacity at −30 °C. By bridging the gap between the ion‐dipole interactions and the evolution of Li+ solvation sheath, this work provides a new technique toward rational design of electrolyte engineering for low‐temperature lithium batteries. [ABSTRACT FROM AUTHOR]

The spatial distribution and transport characteristics of lithium ions (Li+) in the electrochemical interface region of a lithium anode in a lithium ion battery directly determine Li+ deposition behavior. The regulation of the Li+ solvation sheath on the solid electrolyte interphase (SEI) by electrolyte chemistry is key but challenging. Here, 1 m lithium trifluoroacetate (LiTFA) is induced to the electrolyte to regulate the Li+ solvation sheath, which significantly suppresses Li dendrite formation and enables a high Coulombic efficiency of 98.8% over 500 cycles. With its strong coordination between the carbonyl groups (CO) and Li+, TFA− modulates the environment of the Li+ solvation sheath and facilitates fast desolvation kinetics. In addition, due to relatively smaller lowest unoccupied molecular orbital energy than solvents, TFA− has a preferential reduction to produce a stable SEI with uniform distribution of LiF and Li2O. Such stable SEI effectively reduces the energy barrier for Li+ diffusion, contributing to low nucleation overpotential, fast ion transfer kinetics, and uniform Li+ deposition with high cycling stability. This work provides an alternative insight into the design of interface chemistry in terms of regulating anions in the Li+ solvation sheath. It is anticipated that this anion‐tuned strategy will pave the way to construct stable SEIs for other battery systems. [ABSTRACT FROM AUTHOR]

Keywords: dielectric constant; ion-dipole chemistry; lithium metal batteries; low temperature; solvation sheath EN dielectric constant ion-dipole chemistry lithium metal batteries low temperature solvation sheath 1 1 1 07/29/21 20210728 NES 210728 In article number 2100935, Zhenhua Sun, Feng Li and co-workers demonstrate an ion-dipole strategy in which the fluorination degree of solvating agents is altered to accelerate the evolution of the Li SP + sp solvation sheath. Dielectric constant, ion-dipole chemistry, lithium metal batteries, low temperature, solvation sheath Lithium Metal Batteries: Ion-Dipole Chemistry Drives Rapid Evolution of Li Ions Solvation Sheath in Low-Temperature Li Batteries (Adv. [Extracted from the article]

Lithium Anodes: An Anion-Tuned Solid Electrolyte Interphase with Fast Ion Transfer Kinetics for Stable Lithium Anodes (Adv. Keywords: anions; energy barriers; lithium metal anodes; solid electrolyte interphase; solvation sheaths EN anions energy barriers lithium metal anodes solid electrolyte interphase solvation sheaths 1 1 1 04/16/20 20200414 NES 200414 In article number 1903843, Feng Li and co-workers provide an anion-tuned strategy to regulate the electrolyte chemistry of a Li SP + sp solvation sheath, which not only facilitates fast Li SP + sp desolvation kinetics, but significantly reduces the energy barrier during Li SP + sp diffusion through the solid electrolyte interphase, subsequently contributing to uniform Li SP + sp deposition with high cycling stability. Anions, energy barriers, lithium metal anodes, solid electrolyte interphase, solvation sheaths. [Extracted from the article]

Lithium–sulfur (Li–S) batteries, with high theoretical energy density, promise to be the optimal candidate of next‐generation energy‐storage. Rapid development in materials has made a major step forward in Li–S batteries. However, a big gap in cycle life and efficiency for practical applications still remains. Reasonable design of materials/electrodes a is significant aspect that must be addressed. The rising metal‐organic frameworks (MOFs) are a new class of crystalline porous organic–inorganic hybrid materials. Abundant inorganic nodes and designable organic linkers allow tailored pore chemistry at a molecular‐scale, which enables tunable interaction with electroactive components in Li–S batteries. In this review, the interaction between basic component/structure of MOFs and electroactive components in Li–S batteries is clarified to guide precise function‐driven design of MOFs. First, the reaction mechanisms and issues in Li–S batteries are briefly summarized. Second, the structural advantages of MOFs in pore chemistry and morphology are highlighted. Based on the above two aspects of understanding, a bridge between issue‐structure‐function is proposed. The interaction between MOFs with transport and reaction of electroactive components are discussed. Finally, a perspective on the future development of MOFs based materials in Li–S batteries are given. It is believed that the tunable interaction will boost the frontier interdiscipline of MOFs based electrochemical systems. [ABSTRACT FROM AUTHOR]

Abstract: Transition metal phosphides (TMPs) have recently been utilized as promising electrocatalysts for oxygen evolution reaction (OER) in alkaline media. The metal oxides or hydroxides formed on their surface during the OER process are hypothesized to play an important role. However, their exact role is yet to be elucidated. Here unambiguous justification regarding the active role of oxo(hydroxo) species on O‐Ni(1−x)FexP2 nanosheet with pyrite structure is shown. These O‐Ni(1−x)FexP2 (x = 0.25) nanosheets demonstrate greatly improved OER performance than their corresponding hydroxide and oxide counterparts do. From density function theory (DFT) calculations, it is found that the introduction of iron into the pyrite‐phased NiP2 alters OER steps occurred on the surface. Notably, the partially oxidized surface of O‐Ni(1−x)FexP2 nanosheets is vital to improve the local environment and accelerate the reaction steps. This study sheds light on the OER mechanism of the 3d TMP electrocatalyst and opens up a way to develop efficient and low‐cost electrocatalysts. [ABSTRACT FROM AUTHOR]