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Hydrogel electrolytes (HEs) hold great promise in tackling severe issues emerging in aqueous zinc‐ion batteries, but the prevalent salting‐out effect of kosmotropic salt causes low ionic conductivity and electrochemical instability. Herein, a subtle molecular bridging strategy is proposed to enhance the compatibility between PVA and ZnSO4 from the perspective of hydrogen‐bonding microenvironment re‐construction. By introducing urea containing both an H‐bond acceptor and donor, the broken H‐bonds between PVA and H2O, initiated by the SO42−‐driven H2O polarization, could be re‐united via intense intermolecular hydrogen bonds, thus leading to greatly increased carrying capacity of ZnSO4. The urea‐modified PVA‐ZnSO4 HEs featuring a high ionic conductivity up to 31.2 mS cm−1 successfully solves the sluggish ionic transport dilemma at the solid‐solid interface. Moreover, an organic solid‐electrolyte‐interphase can be derived from the in situ electro‐polymerization of urea to prohibit H2O‐involved side reactions, thereby prominently improving the reversibility of Zn chemistry. Consequently, Zn anodes witness an impressive lifespan extension from 50 h to 2200 h at 0.1 mA cm−2 while the Zn‐I2 full battery maintains a remarkable Coulombic efficiency (>99.7 %) even after 8000 cycles. The anti‐salting‐out strategy proposed in this work provides an insightful concept for addressing the phase separation issue of functional HEs. [ABSTRACT FROM AUTHOR]

Gradual disability of Zn anode and high negative/positive electrode (N/P) ratio usually depreciate calendar life and energy density of aqueous Zn batteries (AZBs). Herein, within original Zn2+‐free hydrated electrolytes, a steric hindrance/electric field shielding‐driven "hydrophobic ion barrier" is engineered towards ultradurable (002) plane‐exposed Zn stripping/plating to solve this issue. Guided by theoretical simulations, hydrophobic adiponitrile (ADN) is employed as a steric hindrance agent to ally with inert electric field shielding additive (Mn2+) for plane adsorption priority manipulation, thereby constructing the "hydrophobic ion barrier". This design robustly suppresses the (002) plane/dendrite growth, enabling ultradurable (002) plane‐exposed dendrite‐free Zn stripping/plating. Even being cycled in Zn‖Zn symmetric cell over 2150 h at 0.5 mA cm−2, the efficacy remains well‐kept. Additionally, Zn‖Zn symmetric cells can be also stably cycled over 918 h at 1 mA cm−2, verifying uncompromised Zn stripping/plating kinetics. As‐assembled anode‐less Zn‖VOPO4 ⋅ 2H2O full cells with a low N/P ratio (2 : 1) show a high energy density of 75.2 Wh kg−1full electrode after 842 cycles at 1 A g−1, far surpassing counterparts with thick Zn anode and low cathode loading mass, featuring excellent practicality. This study opens a new avenue by robust "hydrophobic ion barrier" design to develop long‐life anode‐less Zn batteries. [ABSTRACT FROM AUTHOR]

The durability of aqueous zinc-ion batteries (AZIBs) is still impeded due to issues such as dendrite growth, byproduct formation and hydrogen evolution reactions in Zn metal anodes. Herein, we proposed a polydentate ligand, triazole (Ta), as an effective electrolyte additive to prolong the anode stability by its selective adsorption preference and enhanced zinc ion coordination and proton buffering ability. Specifically, Ta induces the formation of an interfacial molecular dam that not only mitigates corrosion via the H2O-deficient electric double-layer (EDL) but also facilitates uniform Zn deposition through its large conjugated planes and zincophilic properties. As a result, a symmetrical cell with the Ta additive exhibits a highly reversible cycle life for 2200 h at 1 mA cm−2 with a capacity of 1 mA h cm−2. Notably, using the Ta/ZnSO4 electrolyte enables stable cycling for 400 h at a high depth-of-discharge (DOD) level of 85%, leading to improved performance in the Zn//α-MnO2 full cell with a lifetime of over 2000 cycles. [ABSTRACT FROM AUTHOR]

Different from "bottom–up" Zn plating/stripping, "top–down" Zn stripping/plating provides a new perspective to reinvent current aqueous Zn batteries (AZBs), yet related studies remain absent. Herein, a chelation‐induced solvation barrier remodeling strategy is initiated toward fast‐kinetics "top–down" Zn stripping/plating in original Zn2+‐free water‐lean organic electrolytes (WLOE) for durable Zn batteries. It is found that in WLOE, the initial Zn stripping kinetics of the Zn anode remarkably limits the "top–down" Zn stripping/plating. The intervention of multidentate chelant (2‐methoxyethylamine, MEA) in WLOE greatly lowers the solvation reorganization energy of in situ stripped Zn2+ from the Zn anode, enabling the fast‐kinetics "top–down" Zn stripping/plating. Spectral characterization and fitted overpotential‐reorganization energy correlation strongly confirm the underlying mechanism. As such, the Zn stripping/plating in the MEA‐mediated WLOE shows a 90‐fold‐enhanced current response, triple‐lowered overpotential, and 170‐fold‐prolonged cyclability (over 1700 h at 0.5 mA cm−2) of those in MEA‐free counterpart. The assembled Zn||LiFePO4 hybrid full cell in MEA‐regulated WLOE exhibits a distinct and high voltage plateau of 1.50 V and a low polarization voltage of 0.14 V, far surpassing those in conventional WLOE. This work opens a new avenue to break the kinetics bottleneck of Zn stripping/plating in WLOE for durable Zn batteries. [ABSTRACT FROM AUTHOR]

Mild aqueous Zn batteries (AZBs) generally suffer a low‐voltage/energy dilemma, which compromises their competitiveness for large‐scale energy storage. Pushing Zn anode potential downshift is an admissible yet underappreciated approach for high‐voltage/energy AZBs. Herein, with a mild hybrid electrolyte containing in situ‐derived diluted strongly‐coordinated Zn2+‐cosolvent pairs, a considerable Zn anode potential downshift is initially achieved for high‐voltage Zn‐based hybrid batteries. The chosen butylpyridine cosolvent not only strongly coordinates Zn2+ ions but also acts as a hydrogen‐bond end‐capping agent to inhibit hydrogen evolution reaction (HER). The electrolyte environment with hetero‐solvation‐diluted strongly‐coordinated Zn2+‐cosolvent pairs remarkably lowers Zn2+ activity, responsible for the Zn electrode potential downshift (−0.330 V vs Zn), confirming to modified Nernst law (ΔE = RTnF$\frac{{RT}}{{nF}}$ln[a(Zn2 +)/a(coordinated solvent)]). With the diluted Zn2+‐containing hybrid electrolyte, the Zn//Zn symmetric cell in the hybrid electrolyte shows a long lifespan over 1270 h at a stripping/plating capacity of 0.4 mA h cm−2. Compared with in common hybrid electrolytes, the as‐assembled Zn‐MnO2 hybrid battery delivers a ca. 0.278 V enhanced voltage plateau (1.57 V) and a long‐term cyclability of over 736 cycles. This work opens a new avenue toward Zn anode potential downshift for high‐voltage AZBs, which can extend to other mild metal batteries. [ABSTRACT FROM AUTHOR]

Aqueous Zn metal batteries hold significant promise for large‐scale energy storage owing to their high safety and low cost. Nevertheless, severe corrosion and uncontrollable dendrite growth hinder the cyclic stability of Zn metal anodes. Herein, a porphyrin‐Zn(II) (ZnTBPP) based multifunctional artificial layer to stabilize Zn anodes by suppression of hydrogen evolution reactions is designed. This hydrophobic interfacial layer repels active water molecules and facilitates the electron transfer from Zn interface to the ZnTBPP layer, thereby increasing the inherent hydrogen evolution potential of Zn anodes. Differential charge density maps reveal that the electron cloud density of the charge transfer layer within the ZnTBPP layer is delocalized due to the electron‐withdrawing effect of Br‐containing functional groups in the ZnTBPP ligands, depleting the interfacial electrons of Zn metal anodes. As a result, H* exhibits a higher Gibbs free energy (∆GH*) of 0.75 eV on Zn with a ZnTBPP coating layer in contrast to bare Zn (0.55 eV), effectively suppressing H2 production. Specifically, the H2 evolution rate of ZnTBPP@Zn (4.06 µmol h−1 cm−2) is ≈2.2 times lower than that of bare Zn. The ZnTBPP@Zn//NaV3O8·1.5H2O full cells exhibit an ultra‐long cycling life of 10 000 cycles at 10 A g−1. [ABSTRACT FROM AUTHOR]

Among six‐electron Te conversion for energetic aqueous Zn batteries, the main capacity contributor, Te0/Te4+ redox usually causes substantial battery capacity/life discount due to its sluggish kinetics/poor reversibility. Herein, for the first time, an offense‐defense‐balanced strategy to simultaneously address the deficiencies is reported. Beyond previous proton‐ or reductant‐regulated solutions, this strategy efficaciously reconciles the pending capacity‐lifespan conflict. As a proof of concept, additive‐level nucleophilic chlorine ions (Cl−) and reductive glucose (Glu) in electrolytes are synergistically employed as "offensiver" and "defender" for Te0/Te4+ conversion, respectively. The Cl−/Glu co‐additive well inherits the nucleophilic motivation effect of Cl− on Te0/Te4+ conversion, and eliminates the formation of Cl−‐induced diffluent metastable phase (γ‐TeO2), enabling a deep and highly reversible Te0/Te4+ redox. Compared with co‐additive‐free electrolytes, the activation energy for Te conversion is lowered (61.4 vs. 52.8 kJ mol−1), and the shuttle of active materials is effectively inhibited. Consequently, Zn‖Te batteries deliver a volumetric capacity of approximately theoretical value (2409 mAh cm−3) at 0.2 A g−1, and a 15∼30‐fold longer lifespan than those in conventional electrolytes (over 5000 cycles with a decay of only 0.15‰ per cycle at 4 A g−1). This work opens a new avenue to develop other chalcogen conversion‐based aqueous Zn batteries. [ABSTRACT FROM AUTHOR]