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The further development of aqueous zinc (Zn)‐ion batteries (AZIBs) is constrained by the high freezing points and the instability on Zn anodes. Current improvement strategies mainly focus on regulating hydrogen bond (HB) donors (H) of solvent water to disrupt HBs, while neglecting the environment of HB‐acceptors (O). Herein, we propose a mechanism of chaotropic cation‐regulated HB‐acceptor via a "super hydrous solvated" structure. Chaotropic Ca2+ can form a solvated structure via competitively binding O atoms in H2O, effectively breaking the HBs among H2O molecules, thereby reducing the glass transition temperature of hybrid 1 mol L−1 (M) ZnCl2+4 M CaCl2 electrolyte (−113.2 °C). Meanwhile, the high hydratability of Ca2+ contributes to the water‐poor solvated structure of Zn2+, suppressing side reactions and uneven Zn deposition. Benefiting from the anti‐freezing electrolyte and high reversible Zn anode, the Zn||Pyrene‐4,5,9,10‐tetraone (PTO) batteries deliver an ultrahigh capacity of 183.9 mAh g−1 at 1.0 A g−1 over 1600‐time stable cycling at −60 °C. This work presents a cheap and efficient aqueous electrolyte to simultaneously improve low‐temperature performances and Zn stability, broadening the design concepts for antifreeze electrolytes. [ABSTRACT FROM AUTHOR]

Organic cathodes for aqueous zinc‐ion batteries (AZIBs) feature intrinsic flexibility and favorable kinetics, but they suffer from high solubility. Herein, a partial charge regulation strategy is deployed by designing a small organic molecule with extended π‐conjugated plane, namely benzo[i]benzo[6′,7′]quinoxalino[2′,3′:9,10]phenanthro[4,5‐abc]phenazine‐5,10,16,21‐tetraone (PTONQ). The charge equalization of active sites induced by the extended π‐conjugated plane of the PTONQ molecule combined with high aromaticity renders the molecule low solubility, fast charge transfer, and high structural stability. The fabricated Zn//PTONQ battery cycles more than 500 h at 175 mA g−1 with small capacity reduction, fast charged/discharged kinetics, and anti‐freeze performance (below ‐20°C). By a series of ex situ characterizations, it is attested that the capacity originates mainly from Zn2+ insertion/removal of PTONQ without H+ incorporation, which also accounts for the formation of Znx(CF3SO3)y(OH)2x‐y·nH2O by‐products. This result benefits the understanding of the by‐product formation mechanism of organic cathode and paves a new way to advance the aqueous Zn‐organic batteries. [ABSTRACT FROM AUTHOR]

The rechargeable Li-CO2 battery has been receiving significant attention owing to its merits of high energy density and the efficient utilization of CO2. However, the widely application is plagued by severe security risks, such as leakage, flammability and lithium dendrites growth due to the use of liquid organic electrolytes. Here, a composite solid state electrolyte consisting of polyethylene oxide (PEO) and 20 wt.% Li7La3Zr1.4Ta0.6O12 (LLZTO) was prepared and first introduced into Li-CO2 battery to solve the problems. The composite solid state electrolyte exhibited high ionic conductivity (1.03 × 10−1 S·cm−1 at 70 °C), wide electrochemical window (5 V vs. Li+/Li), good mechanical properties and excellent flexibility. Ultimately, the Li symmetric cell with PEO/LLZTO composite solid state electrolyte can operate 1,500 h at a current density of 0.1 mA·cm−2. The assembled all-solid-state Li-CO2 battery behaved a long cycle life of 70 cycles at a current density of 100 mA·g−1 with fixed capacity of 1,000 mAh·g−1. Our work provides new perspective to develop rechargeable all-solid-state Li-CO2 batteries. [ABSTRACT FROM AUTHOR]

Due to the merits of low cost, safety, environmental friendliness, and abundant sodium reserves, non-aqueous and aqueous sodium-ion batteries are wonderful alternatives for large-scale energy storage. Na+ super ionic conductor structured Na3V2(PO4)2F3 is considered as a potential high-capacity cathode material for Na-ion batteries. However, its insufficient cyclability remains a challenge for battery applications. In addition, the narrow electrochemical stability window (1.23 V) of aqueous electrolytes does not allow us to make the best use of it. All of these pose obstacles to the practical voltage and energy output. Therefore, we designed and synthesized a Na3V2(PO4)2F3–SWCNT composite, which demonstrated superior Na+-storage performance with a high reversible capacity of 117 mA h g−1 at a moderate current of 0.5C in non-aqueous electrolyte. In addition, we developed an aqueous rechargeable sodium ion battery using Na3V2(PO4)2F3–SWCNT as the cathode and NaTi2(PO4)3–MWCNT as the anode, and this battery can deliver a high energy density of 150 W h kg−1 with an operating voltage of up to 2.0 V by using the high concentration electrolyte, 17 m NaClO4. The outstanding electrochemical performance makes Na3V2(PO4)2F3–SWCNT a promising cathode for Na+ storage and encourages more investigations into practical sodium-ion battery applications. [ABSTRACT FROM AUTHOR]

Garnet Li7La3Zr2O12 (LLZO)-based solid-state electrolytes (SSEs) hold promise for realizing next-generation lithium metal batteries with high energy density. However, the high stiffness of high-temperature sintered LLZO makes it brittle and susceptible to strain during the fabrication of solid-state batteries. Cold-pressed LLZO exhibits improved ductility but suffers from insufficient Li+ conductivity. Here, we report cold-pressed Ta-doped LLZO (Ta-LZ) particles integrated with ductile Li6PS5Cl (LPSC) via a Li+ conductive Li-containing Ta-Cl structure. This configuration creates a continuous Li+ conduction network by enhancing the Li+ exchange at the Ta-LZ/LPSC interface. The resulting Ta-LZ/LPSC SSE exhibits Li+ conductivity of 4.42 × 10-4 S cm-1 and a low activation energy of 0.31 eV. Li symmetric cells with Ta-LZ/LPSC SSE demonstrate excellent Li dendrite suppression ability, with an improved critical current density of 5.0 mA cm-2 and a prolonged cycle life exceeding 600 h at 1 mA cm-2. Our finding provides valuable insights into developing cold-pressed ceramic powder electrolytes for high-performance all-solid-state batteries., (© 2024 Wiley‐VCH GmbH.)

The further development of aqueous zinc (Zn)-ion batteries (AZIBs) is constrained by the high freezing points and the instability on Zn anodes. Current improvement strategies mainly focus on regulating hydrogen bond (HB) donors (H) of solvent water to disrupt HBs, while neglecting the environment of HB-acceptors (O). Herein, we propose a mechanism of chaotropic cation-regulated HB-acceptor via a "super hydrous solvated" structure. Chaotropic Ca 2+ can form a solvated structure via competitively binding O atoms in H 2 O, effectively breaking the HBs among H 2 O molecules, thereby reducing the glass transition temperature of hybrid 1 mol L -1 (M) ZnCl 2 +4 M CaCl 2 electrolyte (-113.2 °C). Meanwhile, the high hydratability of Ca 2+ contributes to the water-poor solvated structure of Zn 2+ , suppressing side reactions and uneven Zn deposition. Benefiting from the anti-freezing electrolyte and high reversible Zn anode, the Zn||Pyrene-4,5,9,10-tetraone (PTO) batteries deliver an ultrahigh capacity of 183.9 mAh g -1 at 1.0 A g -1 over 1600-time stable cycling at -60 °C. This work presents a cheap and efficient aqueous electrolyte to simultaneously improve low-temperature performances and Zn stability, broadening the design concepts for antifreeze electrolytes., (© 2024 Wiley-VCH GmbH.)

The stable cycling of Mg-metal anodes is limited by several problems, including sluggish electrochemical kinetics and passivation at the Mg surface. In this study, we present a high-entropy electrolyte composed of lithium triflate (LiOTf) and trimethyl phosphate (TMP) co-added to magnesium bis(trifluoromethane sulfonyl)imide (Mg(TFSI) 2 /1,2-dimethoxyethane (DME) to significantly improve the electrochemical performance of Mg-metal anodes. The as-formed high-entropy Mg 2+ -2DME-OTf - -Li + -DME-TMP solvation structure effectively reduced the Mg 2+ -DME interaction in comparison with that observed in traditional Mg(TFSI) 2 /DME electrolytes, thereby preventing the formation of insulating components on the Mg-metal anode and promoting its electrochemical kinetics and cycling stability. Comprehensive characterization revealed that the high-entropy solvation structure brought OTf - and TMP to the surface of the Mg-metal anode and promoted the formation of a Mg 3 (PO 4 ) 2 -rich interfacial layer, which is beneficial for enhancing Mg 2+ conductivity. Consequently, the Mg-metal anode achieved excellent reversibility with a high Coulombic efficiency of 98 % and low voltage hysteresis. This study provides new insights into the design of electrolytes for Mg-metal batteries., (© 2023 Wiley-VCH GmbH.)