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Aqueous zinc‐ion batteries (AZIBs) assembled with gel polymer electrolyte (GPE) have gained great popularity due to their low cost and safety. Nevertheless, the extensive utilization of GPE based AZIBs is hindered by various challenges, such as inadequate conductivity, limited mechanical strength, and unstable electrochemical properties. Herein, through the multiple cross‐linking reaction of sodium alginate (SA), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP) and graphene oxide (GO), a hydrated GPE with high conductivity and excellent mechanical property was prepared. GO formed strong hydrogen‐bonding interaction with polymers to build a three‐dimensional network structure for ion migration and improved the mechanical property of GPE. The prepared GPE showed high ionic conductivity of 2.89×10−3 S cm−1 and excellent tensile strength of 900 kPa. In addition, the assembled Zn−Li hybrid battery provided a discharge specific capacity retention rate of 67.6 % and a Coulombic efficiency (CE) of approximate 100 % after 1000 cycles at 1 C. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs), driven by sustainability and cost advantage, have been recognized as one of the most promising electrochemical energy storage devices. Electrolytes, as the most unique component that not only ionically connect while insulating electronically electrodes but also determine the eventual improvements in performance mainly regarding cycle life, Coulombic efficiency, energy density, and safety, hold the key to the practical implementation of SIBs. In this review, the fundamental design principles of Na+‐ion electrolytes and the chemical properties of the Na+ cation over the Li+ cation in terms of ion transport, salt dissolution, and solvation structure are first discussed. Then, a sequence of crucial experimental discoveries and strategical achievements in the field of electrolytes for SIBs are presented, with focuses on the ether‐based electrolytes for co‐intercalation into graphite, diluted and highly concentrated electrolytes, wide temperature range electrolytes, nonflammable electrolytes, indispensable electrolyte components (functional additives and new sodium salts). Finally, a detailed analysis of research trends of practically feasible Na+‐ion electrolytes is presented to aid in the ongoing quest for better SIBs of the future. [ABSTRACT FROM AUTHOR]

Ionic liquid (IL) electrolytes have been widely used in high‐voltage Li‐based dual ion batteries (DIBs) due to their strong resistance against oxidation. However, their applications in Zn‐based DIBs are restricted because the high charge density of divalent Zn2+ aggravates the ionic interactions in ionic networks and leads to insufficient Zn2+ mobility. Herein, we introduce a hydrofluoroether diluent into a Zn‐based IL electrolyte to break down the larger ionic aggregates into smaller ones with weakened ionic interactions. This unique solvation structure reduces the Stokes radius of Zn2+ from 1.3 nm to 0.97 nm and increases its diffusion coefficient by ∼30 times while retaining the high oxidation stability, enabling the charge/discharge cycling of Zn/graphite DIBs at a high rate of 20 C. Moreover, the enhanced mobility of Zn2+ also promotes compact Zn deposition, which allows the operation of anode‐free Zn/graphite DIBs with 90 % capacity retention after 100 cycles. [ABSTRACT FROM AUTHOR]

Owing to the inherent properties combining high ionic conductivity and electrochemical stability, the lithium triborates (LBOs) have emerged as a promising solid-state electrolyte for next-generation batteries. Specific fundamental details of the ionic conduction mechanism and related physicochemical properties remain to be understood. In this study, using the first-principles density functional theory calculations, we present a systematic computational investigation on LBOs in the respect of electronic structures, mechanical and thermodynamic properties, Li-ion transport, and interfacial (with Li metal) behaviors. Our results show that LBO is a thermodynamically and mechanically stable insulator with an indirect wide bandgap of 6.4 eV. Notably, LBOs could behave as a fast Li-ion conductor with a low migration energy barrier (15 meV) and are characterized by a zig–zag Li+-diffusion path along the c direction. We found that the interface between Li metal and LBO is both physically and chemically stable with no new phase formed while exhibiting a metallic character due to the charge transfer from a Li metal. Our study highlights the intriguing promise of LBOs as solid-state electrolytes for high-energy cells. [ABSTRACT FROM AUTHOR]

Rechargeable magnesium batteries (RMBs) have great potential in the field of high‐temperature specialized batteries owing to the superior thermostability and lower propensity for dendrite formation of Mg metal anodes. And the development of Mg2+‐conducting electrolytes that can operate stably under elevated temperature conditions (>100 °C) is the key to high‐temperature RMBs. Here, a robust self‐standing single‐ion polymer electrolyte (SSPE) enabling high‐safety RMBs working at elevated temperature is presented. This SSPE exhibits an expanded electrochemical stability window of 4.8 V (vs Mg2+/Mg), a remarkable Mg2+‐ion transference number of 0.79, and a highly reversible Mg plating/stripping performance. This rationally designed SSPE enables home‐made Mo6S8//Mg batteries with superior high‐temperature (up to 150 °C) performance and significantly improved safety characteristics under abuse conditions. This design concept for a robust SSPE provides a promising path to high‐safety specialized RMBs operating at the elevated temperature, which also offers a new path for the development of functionalized electrolytes. [ABSTRACT FROM AUTHOR]

Solid‐state zinc (Zn) batteries offer a new candidate for emerging applications sensitive to volume, safety and cost. However, current solid polymeric or ceramic electrolyte structures remain poorly conductive for the divalent Zn2+, especially at room temperature. Constructing a heterogeneous interface which allows Zn2+ percolation is a viable option, but this is rarely involved in multivalent systems. Herein, we construct a solid Zn2+‐ion conductor by inducing crystallization of tailored eutectic liquids formed by organic Zn salts and bipolar ligands. High‐entropy eutectic‐networks weaken the ion‐association and form interfacial Zn2+‐percolated channels on the nucleator surfaces, resulting in a solid crystal with exceptional selectivity for Zn2+ transport (tZn2+ =0.64) and appreciable Zn2+ conductivity (σZn2+ =3.78×10−5 S cm−1 at 30 °C, over 2 orders of magnitude higher than conventional polymers), and finally enabling practical ambient‐temperature Zn/V2O5 metal solid cells. This design principle leveraged by the eutectic solidification affords new insights on the multivalent solid electrochemistry suffering from slow ion migration. [ABSTRACT FROM AUTHOR]

It is demonstrated that a novel eutectic solution including 1,3,5‐trioxane (TXE) and succinonitrile (SN) can be converted into solid‐state polymer electrolyte (SPE) via in situ polymerization triggered by lithium difluoro(oxalato)borate (LiDFOB). It is worth noting that all the precursors (LiDFOB, TXE, and SN) of this novel SPE are totally solid and nonvolatile at room temperature, where, LiDFOB works as a lithium salt and an initiator simultaneously to avoid the introduction of impurity. It is noted that such SPE presents a considerable ionic conductivity of 1.14 × 10−4 S cm−1 and a sufficiently wide electrochemical window of 4.5 V, which is significant for supporting the high‐energy lithium batteries. In addition, this dedicatedly designed in situ polymerization is powerful to build kinetically favorable polymer‐based protective layers on LiCoO2 cathode and Li metal anode simultaneously, guaranteeing outstanding cycling stability (capacity retention of 88% after 200 cycles) of 4.3 V LiCoO2/lithium metal batteries at room temperature. More intriguingly, soft packed LiCoO2/SPE/Li metal batteries can still light a blue light emitting diode (LED) under the harsh conditions of being bent, cut, and stroked by a hammer, demonstrating excellent safety characteristics. [ABSTRACT FROM AUTHOR]

Cover Feature: Rational Design of Functional Electrolytes Towards Commercial Dual-Ion Batteries (ChemSusChem 4/2023) Keywords: dual-ion batteries; electrochemistry; electrolytes; energy density; energy storage EN dual-ion batteries electrochemistry electrolytes energy density energy storage 1 1 1 02/23/23 20230220 NES 230220 B The Cover Feature b shows a dual-ion battery based on anion intercalation into graphite cathode for grid-scale energy storage. Dual-ion batteries, electrochemistry, electrolytes, energy density, energy storage. [Extracted from the article]

[Display omitted] • All-amorphous PEO-based Zn2+ solid polymer electrolyte is designed. • In-situ polymerization process endows compatible interfaces. • Highly reversible solid-state Zn electrochemistry is achieved. The revival of rechargeable zinc (Zn)-ion batteries was overshadowed by the deep-seated issues of dendrite growth and intricate side-reactions in routine aqueous electrolytes. Poly (ethylene oxide) (PEO)-based solid-state polymer electrolytes (SPEs) are potentially promising to address these issues, but the valid Zn2+ conduction and proper Zn electrochemistry have been difficult of accomplishment due to the high-degree crystallization of PEO and its interfacial incompatibility with stiff Zn metal. Herein, we bypass these obstacles by the in-situ polymerization of the stark but hand-picked monomer, poly(ethylene glycol) methyl ether acrylate, characterized by the long side-chains with pendant ethylene oxide units, to construct the all-amorphous Zn2+ SPEs for the first time. The long side-chains favor the formation of amorphous matrix while the in-situ process endows compatible electrolyte/electrode interfaces, thus leading to a high ambient ionic conductivity (2.87 × 10−5 S cm−1) as well as low interfacial resistances. The demonstration of this SPE in solid state Zn/Zn symmetrical cells and rechargeable Zn/Mo 6 S 8 cells with long life-spans signifies the highly reversible and dendrite-free Zn electrochemistry. Our results lay groundwork not only for Zn but for other multivalent-metal batteries suffering from poor bulk and interfacial ion transport to construct the rechargeable all-solid-state batteries. [ABSTRACT FROM AUTHOR]