Cuiping Han

The separator critically dictates liquid‐phase mass transport in aqueous zinc‐ion batteries (AZIBs), while it is poorly regulated in conventional commercial separators due to inappropriate pore structure and heterogeneous surface charge. Herein, we engineer a multifunctional separator (PTT‐GF‐D) that integrates ordered nanoporous channels with highly negatively charged surface to synchronously regulate ion flux and interfacial electric fields. This design effectively optimizes liquid‐phase mass transport, thereby promoting homogeneous multi‐site nucleation, accelerating Zn ²⁺ desolvation, and mitigating Zn ²⁺ concentration polarization. Consequently, the symmetric cells achieve exceptional reversibility, stably operating for 3300 h under 1 mA cm ⁻² , 1 mAh cm ⁻² and maintaining robust stability over 1000 h even under harsh conditions of 10 mA cm ⁻² , 10 mAh cm ⁻² . The as‐fabricated Zn||MnO ₂ full cell delivers a specific capacity of 130 mAh g ⁻¹ at 1 A g ⁻¹ , preserving 96.2% of its initial capacity after 1000 cycles. A large‐sized pouch cell is also demonstrated, which can operate at 5 mA cm ⁻² for 100 cycles without noticeable decay. This study establishes the critical synergy of pore architecture and surface charge engineering in separators to control liquid‐phase mass transport, offering a promising strategy for developing high‐performance and practical AZIBs.

Aqueous zinc‐ion batteries (AZIBs) are constrained by unstable Zn metal interfaces, where nonuniform Zn ²⁺ transport induces concentration polarization and accelerates parasitic reactions. Here we show that Zn ²⁺ flux can instead be regulated by aqueous–aqueous interfaces. A fully aqueous “water‐in‐water” (W/W) biphasic electrolyte, comprising dextran (Dex)‐rich phase droplets (∼10 µm) suspended in a polyethylene glycol (PEG)‐rich aqueous phase, creates phase boundaries that continuously buffer local Zn ²⁺ accumulation and redistribute ions during plating and stripping. As a result, Zn||Zn cells cycle stably for 1100 h at 10 mA cm ⁻² and 10 mAh cm ⁻² , and Ah‐level Zn||NaV ₃ O ₈ pouch cells sustain long‐term operation. This work demonstrates an aqueous electrolyte architecture in which interfacial electrostatics, rather than solvent chemistry, governs Zn ²⁺ transport.

Dendrite formation on Zn metal anodes remains a major obstacle to the practical deployment of aqueous Zn-ion batteries. The plating-induced stress in Zn anodes and its effect on Zn-deposition morphologies have not been fully elucidated. Herein, we establish a direct correlation between plating-induced stress and dendrite initiation. We reveal that localized tensile/compressive-stress heterogeneity modulates the chemical potential of deposited Zn, generating spatial chemical-potential gradients and nonuniform deposition kinetics at the Zn/electrolyte interface. Such stress-induced chemical-potential differences promote preferential Zn growth at protruded regions and accelerate interfacial instability, whereas stress homogenization suppresses localized deposition and mitigates dendrite evolution. Based on this, we introduced a stress-relieving additive that selectively adsorbs on Zn (100) facets and guides a (100) textured Zn anode. This flattens the Zn deposition and establishes a homogeneous compressive-stress distribution with reduced local chemical-potential differences, effectively suppressing stress-driven dendrite formation. Consequently, the Zn anode has a high cycling life of 3500 h in the symmetric Zn||Zn cell. The Zn||I2 full cell shows remarkable long-term stability exceeding 10,000 cycles at 2 A g–1. This work unveils the intrinsic interplay between stress evolution and dendritic morphology, providing a viable interfacial stress-regulation strategy for dendrite-free metal anodes.

Hydrogels are widely used as quasi‐solid‐state electrolytes (QSEs) in batteries due to their favorable mechanical properties. However, a critical fundamental phenomenon has remained largely overlooked: the electro‐chemo‐mechanical evolution of the hydrogel under an electric field. A real‐time electric‐field‐induced deformation in a polyacrylamide (PAM) hydrogel electrolyte is observed, mainly driven by the Zn ^… O and Zn ^… N adhesion between PAM and Zn under an electric field. This irreversible deformation can induce interfacial separation at the cathode‐hydrogel interface, reducing battery life. To solve this problem, a double‐layer electrolyte (DLE) is constructed to couple the PAM with a sodium polyacrylate (PANa) hydrogel. The PANa layer undergoes expansive deformation aligned with the electric field, effectively counteracting the contraction of the PAM hydrogel and actively maintaining interfacial contact during cycling. In addition, the redox electrolyte in PANa provides an additional energy density and forms a zinc ferricyanide (ZnHCF) coating on the Zn anode that improves the Zn deposition kinetics. As a result, the zinc‐sodium hybrid battery (ZSHB) assembled using DLE exhibits an initial discharge capacity of 117 mAh g ⁻¹ at 0.2 A g ⁻¹ , approximately 20% higher than that of the PAM cell, and retains 81.6% of its capacity after 1000 cycles.

In aqueous battery systems, proton co‐storage commonly accompanies the insertion of charge carriers, yet its influence on interfacial electrochemistry remains poorly understood. Here, a covalent polymer (PCD) is reported as an anode material for aqueous calcium‐ion batteries, operating through a Ca ²⁺ /H ⁺ storage mechanism associated with redox‐active C═N moieties. Proton adsorption dynamically modifies the interfacial microenvironment and induces the reversible formation of a Ca(OH) ₂ surface phase. Rather than impairing performance, this proton‐mediated interfacial Ca(OH) ₂ effectively suppresses hydrogen evolution, enabling stable operation at extended negative potentials. As a result, the PCD anode delivers high capacity, rapid charge–discharge response, and exceptional cycling stability. A 43 mAh pouch cell retains 80.4% of its capacity over 1900 cycles (>1000 h), representing a significant step forward in aqueous Ca ²⁺ storage. These findings reveal that proton‐induced interfacial phases can be harnessed to regulate parasitic reactions, offering a new paradigm for the design of stable aqueous battery electrodes.

Developing large‐scale, dendrite‐free zinc (Zn) anodes is pivotal for the practical deployment of aqueous Zn‐metal batteries (AZMBs), yet maintaining interfacial stability under high‐areal‐capacity conditions remains challenging. Here, we report an adaptive artificial solid‐electrolyte interphase (ASEI) based on a single‐ion‐conducting fluorine‐rich double network (SFDN) that enables in situ dynamic reconstruction of the Zn/electrolyte interphase. The SFDN, comprising an Al(OR) ₄ ⁻ ‐based (R = −CH ₂ −(CF ₂ ) ₇ −CH ₂ −) dynamic crosslinked network integrated within PVDF‐HFP matrix, delivers a high Zn ²⁺ transference number (0.78) and hydrophobic/zincophilic properties. During cycling, residual monomers within the SFDN fulfill a dual‐functional role: coordinating with Zn ²⁺ to establish a dynamic Zn(OR) ₂ ⁻ ‐based network while undergoing sacrificial decomposition to form a robust ZnF ₂ ‐rich inner SEI. This evolution yields a multilayered architecture that effectively suppresses water‐induced side reactions, homogenizes Zn ²⁺ flux, and provides self‐healing. Consequently, the SFDN@Zn anode achieves an extraordinary lifespan of over 4,000 h at 10 mA cm ^{− 2} /10 mAh cm ^{− 2} , and a high average Coulombic Efficiency of 99.9% at 5 mA cm ^{− 2} . Furthermore, a ∼900 mAh Zn||I ₂ pouch cell achieves a high energy density of 196 Wh kg ^{− 1} with 97.8% capacity retention over 300 cycles. This work presents a dynamic self‐adaptive interphase engineering, offering fundamental insights into Zn‐anode stabilization, and extending to other metal‐based battery systems.

Organic electrode materials (OEMs) offer tunable molecular structures and sustainability. To meet the requirements for applications, a high mass‐loading electrode is essential. However, as the mass loading of an electrode increases and the electrode thickens, the electrochemical kinetics significantly deteriorate. Here, we propose an intramolecular hydrogen‐bond strategy that disrupts this seesaw effect, enabling high areal capacity even at high mass‐loadings. Poly(2,3,7,8‐tetraaminophenazine‐1,4,6,9‐tetraone) (PTAPT) was synthesized as a representative material. During discharge, protons as charge carriers diffuse into the material. We use these protons to combine with active sites (C═O/C═N) of PTAPT. This interaction generates secondary intramolecular hydrogen bonds within PTAPT and concurrently forms consecutive proton transport channels. The proton diffusion energy barrier is substantially reduced, facilitating rapid proton conduction along these pathways via the Grotthuss mechanism. Consequently, a proton‐dominated charge transport mechanism occurs in PTAPT, significantly enhancing ion‐transport kinetics in thick electrodes. Furthermore, the extended proton conduction channels increase the degree of structural conjugation, endowing PTAPT with excellent electronic conductivity. A single‐layer pouch cell delivers a maximum discharge capacity of 249 mAh and a significant areal capacity of 5 mAh cm ⁻² . This work provides a novel strategy to improve the area capacity of OEMs, representing a key step toward their practical application.

High energy density and long cycle life are critical for practical aqueous zinc‐iodine batteries (AZIBs). However, the development of high‐mass‐loading iodine cathodes faces bottlenecks, such as structural instability, severe polyiodide shuttling, and sluggish charge transfer kinetics. Herein, a robust biopolymer network (XGP) binder is developed, featuring a 3D network structure with dense hydrogen bonding that provides strong adhesion and good mechanical strength for high‐mass‐loading active carbon (AC)@I ₂ cathodes. Using a scalable slurry‐drawing method, the obtained thick AC@I ₂ electrodes exhibit a porous architecture with high porosity (47.6%), facilitating rapid Zn ^{2 +} diffusion (up to 10 ⁻⁹ cm ² s ⁻¹ ) and fast electrochemical kinetics. Furthermore, diverse oxygen functional groups in the XGP binder provide strong chemical anchoring sites, effectively suppressing polyiodide shuttling. Consequently, XGP‐based cathodes with an ultrahigh iodine loading (82 mg cm ⁻² , ∼960 µm) achieve an areal capacity of 15.3 mAh cm ⁻² . Zn‐I ₂ pouch cells deliver a capacity of 1744 mAh over 600 cycles, yielding a remarkable energy density of 55.0 Wh L ⁻¹ at the cell level. This work solves key challenges in thick iodine electrodes through integrated design of the biopolymer binder and electrode engineering, paving the way for practical AZIBs.