Qianwei Huang

The reversibility of Zn anodes is severely compromised by dendritic growth and parasitic hydrogen evolution reactions. Directing Zn to undergo grain‐oriented stripping offers an effective approach to mitigating these issues. However, this strategy has rarely been explored, and the underlying mechanism remains unclear. Herein, we design a multifunctional hydrogel composed of aramid nanofiber‐polyvinyl alcohol (ANF‐PVA) and calcium lignosulfonate (LS) to dynamically regulate the anode interface. The ANF‐PVA hydrogel framework possesses excellent mechanical stability and a uniform porous structure that promotes a homogeneous electric field distribution. Concurrently, the incorporated LS preferentially adsorbs onto specific Zn crystal planes, which equilibrates the stripping energy barrier. Through the synergistic regulation between ANF‐PVA and LS, grain‐oriented dissolution is achieved. The in situ formed solid electrolyte interphase (SEI) can further guide uniform Zn deposition and effectively suppress side reactions. Consequently, Zn||Zn symmetric cells exhibit exceptional cycling stability under both ambient (5000 h at 2 mA cm ⁻² /1 mAh cm ⁻² ) and low‐temperature conditions (10 900 h at −40 °C). The Zn||I ₂ full cell achieves 78.2% capacity retention after 20 000 cycles at 5 A g ⁻¹ . Remarkably, pouch‐type cells also sustain 700 cycles. This work opens a new avenue for achieving highly reversible Zn anodes through grain‐oriented dissolution.

The reversibility of Zn anodes is severely compromised by dendritic growth and parasitic hydrogen evolution reactions. Directing Zn to undergo grain‐oriented stripping offers an effective approach to mitigating these issues. However, this strategy has rarely been explored, and the underlying mechanism remains unclear. Herein, we design a multifunctional hydrogel composed of aramid nanofiber‐polyvinyl alcohol (ANF‐PVA) and calcium lignosulfonate (LS) to dynamically regulate the anode interface. The ANF‐PVA hydrogel framework possesses excellent mechanical stability and a uniform porous structure that promotes a homogeneous electric field distribution. Concurrently, the incorporated LS preferentially adsorbs onto specific Zn crystal planes, which equilibrates the stripping energy barrier. Through the synergistic regulation between ANF‐PVA and LS, grain‐oriented dissolution is achieved. The in situ formed solid electrolyte interphase (SEI) can further guide uniform Zn deposition and effectively suppress side reactions. Consequently, Zn||Zn symmetric cells exhibit exceptional cycling stability under both ambient (5000 h at 2 mA cm ⁻² /1 mAh cm ⁻² ) and low‐temperature conditions (10 900 h at −40 °C). The Zn||I ₂ full cell achieves 78.2% capacity retention after 20 000 cycles at 5 A g ⁻¹ . Remarkably, pouch‐type cells also sustain 700 cycles. This work opens a new avenue for achieving highly reversible Zn anodes through grain‐oriented dissolution.

The development of highly active and stable cathodes in alkaline solutions is crucial for promoting the commercialization of anion exchange membrane (AEM) electrolyzers, yet it remains a significant challenge. Herein, we synthesized atomically dispersed CoP₄ moieties (CoP₄-SSC) immobilized on ultrathin carbon nanosheets via a phosphidation exfoliation strategy at medium temperature. The thermodynamic formation process of the Co-P moieties was elucidated using X-ray absorption spectroscopy (XAS) and theoretical calculations. Remarkably, the resulting CoP₄-SSC electrocatalyst exhibited outstanding activity for alkaline hydrogen evolution, with a low overpotential of 52 mV at 10 mA cm^-2 and a turnover frequency of up to 23.83 s^-1. Moreover, the AEM electrolyzer fabricated with CoP₄-SSC achieved a current density of 1 A cm^-2 under an applied voltage of only 1.94 V, showing negligible degradation after 500 h of continuous electrocatalysis. A series of operando characterizations and density functional theory calculations revealed that the atomically dispersed Co-P moieties formed a nanointerface of [P-*H···H₂O*-Co], which facilitates water dissociation during the Volmer-Heyrovsky pathway.

The chlor-alkali process plays an essential and irreplaceable role in the modern chemical industry due to the wide-ranging applications of chlorine gas. However, the large overpotential and low selectivity of current chlorine evolution reaction (CER) electrocatalysts result in significant energy consumption during chlorine production. Herein, we report a highly active oxygen-coordinated ruthenium single-atom catalyst for the electrosynthesis of chlorine in seawater-like solutions. As a result, the as-prepared single-atom catalyst with Ru-O₄moiety (Ru-O₄SAM) exhibits an overpotential of only ~30 mV to achieve a current density of 10 mA cm⁻²in an acidic medium (pH = 1) containing 1 M NaCl. Impressively, the flow cell equipped with Ru-O₄SAM electrode displays excellent stability and Cl₂selectivity over 1000 h continuous electrocatalysis at a high current density of 1000 mA cm⁻². Operando characterizations and computational analysis reveal that compared with the benchmark RuO₂electrode, chloride ions preferentially adsorb directly onto the surface of Ru atoms on Ru-O₄SAM, thereby leading to a reduction in Gibbs free-energy barrier and an improvement in Cl₂selectivity during CER. This finding not only offers fundamental insights into the mechanisms of electrocatalysis but also provides a promising avenue for the electrochemical synthesis of chlorine from seawater electrocatalysis.

Domain walls (DWs) in ferroelectric materials are interfaces that separate domains with different polarizations. Charged domain walls (CDWs) and neutral domain walls are commonly classified depending on the charge state at the DWs. CDWs are particularly attractive as they are configurable elements, which can enhance field susceptibility and enable functionalities such as conductance control. However, it is difficult to achieve CDWs in practice. Here, we demonstrate that applying mechanical stress is a robust and reproducible approach to generate CDWs. By mechanical compression, CDWs with a head/tail-to-body configuration were introduced in ultrathin BaTiO₃, which was revealed by in-situ transmission electron microscopy. Finite element analysis shows strong strain fluctuation in ultrathin BaTiO₃ under compressive mechanical stress. Molecular dynamics simulations suggest that the strain fluctuation is a critical factor in forming CDWs. This study provides insight into ferroelectric DWs and opens a pathway to creating CDWs in ferroelectric materials.

The current approach to achieving superior energy storage density in dielectrics is to increase their breakdown strength, which often incurs heat generation and unexpected insulation failures, greatly deteriorating the stability and lifetime of devices. Here, a strategy is proposed for enhancing recoverable energy storage density (W_r) while maintaining a high energy storage efficiency (η) in glassy ferroelectrics by creating super tetragonal (super‐T) nanostructures around morphotropic phase boundary (MPB) rather than exploiting the intensely strong electric fields. Accordingly, a giant W_r of ≈86 J cm⁻³ concomitant with a high η of ≈81% is acquired under a moderate electric field (1.7 MV cm⁻¹) in thin films having MPB composition, namely, 0.94(Bi, Na)TiO₃‐0.06BaTiO₃ (BNBT), where the local super‐T polar clusters (tetragonality ≈1.25) are stabilized by interphase strain. To the knowledge of the authors, the W_r of the engineered BNBT thin films represents a new record among all the oxide perovskites under a similar strength of electric field to date. The phase field simulation results ascertain that the improved W_r is attributed to the local strain heterogeneity and the large spontaneous polarization primarily is originated from the super‐T polar clusters. The findings in this work present a genuine opportunity to develop ultrahigh‐energy‐density thin‐film capacitors for low‐electric‐field‐driven nano/microelectronics.

Metals with nanocrystalline grains have ultrahigh strengths approaching two gigapascals. However, such extreme grain-boundary strengthening results in the loss of almost all tensile ductility, even when the metal has a face-centred-cubic structure—the most ductile of all crystal structures^1,2,3. Here we demonstrate that nanocrystalline nickel–cobalt solid solutions, although still a face-centred-cubic single phase, show tensile strengths of about 2.3 gigapascals with a respectable ductility of about 16 per cent elongation to failure. This unusual combination of tensile strength and ductility is achieved by compositional undulation in a highly concentrated solid solution. The undulation renders the stacking fault energy and the lattice strains spatially varying over length scales in the range of one to ten nanometres, such that the motion of dislocations is thus significantly affected. The motion of dislocations becomes sluggish, promoting their interaction, interlocking and accumulation, despite the severely limited space inside the nanocrystalline grains. As a result, the flow stress is increased, and the dislocation storage is promoted at the same time, which increases the strain hardening and hence the ductility. Meanwhile, the segment detrapping along the dislocation line entails a small activation volume and hence an increased strain-rate sensitivity, which also stabilizes the tensile flow. As such, an undulating landscape resisting dislocation propagation provides a strengthening mechanism that preserves tensile ductility at high flow stresses.

Ferroelectric nanoplates are attractive for applications in nanoelectronic devices. Defect engineering has been an effective way to control and manipulate ferroelectric properties in nanoscale devices. Defects can act as pinning centers for ferroelectric domain wall motion, altering the switching properties and domain dynamics of ferroelectrics. However, there is a lack of detailed investigation on the interactions between defects and domain walls in ferroelectric nanoplates due to the limitation of previous characterization techniques, which impedes the development of defect engineering in ferroelectric nanodevices. In this study, we applied in situ biasing transmission electron microscopy to explore how dislocation loops, which were judiciously introduced into barium titanate nanoplates via electron beam irradiation, affect the motion of ferroelectric domain walls. The results show that the motion was dramatically suppressed by these localized defects, because of the local strain fields induced by the defects. The pinning effect can be further enhanced by multiple domain walls embedded with defect arrays. These results indicate the possibility of manipulating domain switching in ferroelectric nanoplates via the electron beam.

Ferroelectricity is engineered by dimension in nanoscale single-crystal ferroelectrics.