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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]

Bipolar organic cathode materials (OCMs) implementing cation/anion storage mechanisms are promising for high‐energy aqueous Zn batteries (AZBs). However, conventional organic functional group active sites in OCMs usually fail to sufficiently unlock the high‐voltage/capacity merits. Herein, we initially report dynamically ion‐coordinated bipolar OCMs as cathodes with chalcogen active sites to solve this issue. Unlike conventional organic functional groups, chalcogens bonded with conjugated group undergo multielectron‐involved positive‐valence oxidation and negative‐valence reduction, affording higher redox potentials and reversible capacities. With phenyl diselenide (PhSe‐SePh, PDSe) as a proof of concept, it exhibits a conversion pathway from (PhSe)− to (PhSe‐SePh)0 and then to (PhSe)+ as unveiled by characterization and theoretical simulation, where the diselenide bonds are periodically broken and healed, dynamically coordinating with ions (Zn2+ and OTF−). When confined into ordered mesoporous carbon (CMK‐3), the dissolution of PDSe intermediates is greatly inhibited to obtain an ultralong lifespan without voltage/capacity compromise. The PDSe/CMK‐3 || Zn batteries display high reversibility capacity (621.4 mAh gPDSe−1), distinct discharge plateau (up to 1.4 V), high energy density (578.3 Wh kgPDSe−1), and ultralong lifespan (12 000 cycles) at 10 A g−1, far outperforming conventional bipolar OCMs. This work sheds new light on conversion‐type active site engineering for high‐voltage/capacity bipolar OCMs towards high‐energy AZBs. [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]

Zn powder is considered as a potential Zn metal anode for aqueous Zn‐ion batteries. However, restricted ion/electron transfer and volume effect‐caused electrical contact failure in conventional polymer binder composited Zn powder anodes deteriorate their electrochemical performance. Here, a high‐performance soft solid‐like viscoelastic Zn powder composite anode is proposed based on an oligomer gluing strategy. Benefiting from the viscoelastic properties, the soft‐solid Zn powder composite (ss‐ZnP) anode has significantly enhanced charge transfer, alleviated volume effect, and homogenized interfacial electric field, leading to fast plating/stripping kinetics and dendrite‐free deposition morphology. Furthermore, the assembled NH4V4O10‖ss‐ZnP full cell delivers higher capacity (510 mAh g−1 at 0.1A g−1, 300 mAh g−1 at 1A g−1) and longer lifespan up to 500 cycles at 1 A g−1, superior to conventional polymer binder composited Zn powder anode and other reported rheological Zn powder‐based anodes. Apart from the electrochemical merits, this soft matter‐based design also endows the ss‐ZnP electrode with free‐standing and malleable properties which greatly expand its practical application. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable Mg batteries (ARMBs) usually fail from severe anode passivation, alternatively, executing quasi‐underpotential Mg plating/stripping chemistry (UPMC) on a proper heterogeneous metal substrate is a crucial remedy. Herein, a stable UPMC on Zn substrate is initially achieved in new hydrated eutectic electrolytes (HEEs), delivering an ultralow UPMC overpotential and high energy/voltage plateau of ARMBs. The unique eutectic property remarkably expands the lower limit of electrochemical stability window (ESW) of HEEs and undermines the competition between hydrogen evolution/corrosion reactions and UPMC, enabling a reversible UPMC. The UPMC is carefully revealed by multiple characterizations, which shows a low overpotential of 50 mV at 0.1 mA cm−2 over 550 h. With sulfonic acid‐doped polyaniline (SPANI) cathodes, UPMC‐based full cells show high energy/power densities of 168.6 Wh kg−1/2.1 kWh kg−1 and voltage plateau of 1.3 V, far overwhelming conventional aqueous systems. [ABSTRACT FROM AUTHOR]

The anode‐cathode interplay is an important but rarely considered factor that initiates the degradation of aqueous zinc ion batteries (AZIBs). Herein, to address the limited cyclability issue of V‐based AZIBs, Al2(SO4)3 is proposed as decent electrolyte additive to manipulate OH−‐mediated cross‐communication between Zn anode and NaV3O8 ⋅ 1.5H2O (NVO) cathode. The hydrolysis of Al3+ creates a pH≈0.9 strong acidic environment, which unexpectedly prolongs the anode lifespan from 200 to 1000 h. Such impressive improvement is assigned to the alleviation of interfacial OH− accumulation by Al3+ adsorption and solid electrolyte interphase formation. Accordingly, the strongly acidified electrolyte, associated with the sedated crossover of anodic OH− toward NVO, remarkably mitigate its undesired dissolution and phase transition. The interrupted OH−‐mediated communication between the two electrodes endows Zn||NVO batteries with superb cycling stability, at both low and high scan rates. [ABSTRACT FROM AUTHOR]

Organic/inorganic hybrid artificial functional layer (AFL) designs of Zn anode have witnessed good progress in stabilizing the Zn anode. However, such processes remain uncapable of simultaneously providing durable protection and fast Zn2+ migration, especially in high‐rate scenarios. Herein, intrinsic hydrogen‐bond donor (HBD)‐lined organophosphate superionic nanochannels are initially engineered to address this challenge. Due to unique ordered nanochannels with a smaller diameter than that of hydrated Zn2+ ions and polyanions, hydroxymethyl Zn phosphates (Zn(O3PCH2OH, ZnOPC) are first considered for AFL design. The small size can provide an interception for polyanions. Density functional theory calculation indicates that ZnOPC nanochannels possess a 35% lower Zn2+ migration energy barrier than conventional Zn phosphate, highly consistent with tested results. Additionally, as HBDs, rich ‐CH2OH groups located at nanochannels impose a targeted hydrogen‐bonding interaction with water molecules. Consequently, at an ultrahigh current density up to 50 mA cm−2, the Zn@ZnOPC anode shows a 36% lower overpotential than that of the bare Zn anode. As‐assembled Zn @ ZnOPC//NaV3O8 · 1.5H2O full cells exhibit an ultralong lifespan of 20 000 cycles at 20 A g−1, with a low capacity‐decay of 0.016% per cycle. This work features a targeted hydrogen bonding‐enhanced desolvation effect occurring in organophosphate superionic nanochannels, which would enlighten to explore reliable fast‐charging aqueous batteries. [ABSTRACT FROM AUTHOR]

Underachieved capacity and low voltage plateau is ubiquitous in conventional aqueous magnesium ion full batteries. Such limitations originate from the electrochemistry and the low carrier‐hosting ((de)intercalation) potential of electrode materials. Herein, via a strategy of enhancing the electrochemistry through carrier‐hosting potential compensation, high‐energy Mg2+/Na+ hybrid batteries are achieved. A Mg1.5VCr(PO4)3 (MVCP) cathode is coupled with FeVO4 (FVO) anode in a new aqueous/organic hybrid electrolyte, giving reliable high‐voltage operation. This operation enables more sufficient (de)intercalation of hybrid carriers (Mg2+/Na+), thereby enhancing the reversible capacity remarkably (233.4 mA h g−1 at 0.5 A g−1, 92.7 Wh kg−1electrode, that is, ≥1.75‐fold higher than those in conventional aqueous electrolytes). The relatively high Na+‐hosting potential of the electrodes compensates for the low Mg2+‐hosting potential and widens/elevates the discharge plateau of the full battery up to 1.50 V. Mechanism study further reveals an unusual phase transformation of FVO to Fe2V3 and the low‐lattice‐strain pseudocapacitive (de)intercalation chemistry of MVCP. [ABSTRACT FROM AUTHOR]

Free-standing flexible sodium-ion battery anodes are fabricated by NH 3 treating coal tar pitch/polyacrylonitrile based electrospun nanofibers. The carbon nanofiber films (NCFs) consist of disordered carbon matrix with well distributed graphitic microdomains. The disordered carbon matrix with enlarged interlay distance greatly enhances Na + transfer kinetics. And the graphitic microdomains distributed throughout the entire matrix as a result of the addition of pitch form conductive network, which facilitates electron transfer. Micro/mesopores resulting from the NH 3 treatment combined with interconnected network structure facilitate the access of electrolyte to the electrode and Na + diffusion. Benefiting from these structural features, NCFs achieve a high reversible capacity of 341 mA h g −1 at 0.1 A g −1 in the half sodium-ion cells. Even after an ultralong cycling of 10 000 times, specific capacities of 235 and 217 mA h g −1 can still be retained at 1 and 2 A g −1 , respectively. Furthermore, the flexible sodium-ion full batteries which consist of NCFs anode and Na 3 V 2 (PO 4 ) 3 @C cathode show excellent rate performance and good cycling capability, with a stable discharge plateau of 3.3–2.2 V under different flexing angles. This novel high-performance carbon nanofiber film anode holds great potential in future flexible and wearable sodium-ion batteries. [ABSTRACT FROM AUTHOR]