Yaping Zhang

Anion exchange membrane (AEM) with high ion conductivity and effective interfacial regulation is crucial for electrocatalytic CO ₂ reduction (ECR). Herein, we design a fluorinated polybenzimidazole (6FPBI) grafted with both piperidinium and trimethylammonium cations to fabricate a high‐performance AEM. Benefiting from ether‐free fluorinated backbone and dual cation group, 6FPBI‐TP membrane exhibits IEC of 3.63 mmol g ^{− 1} , suppressed water uptake of 50.44%, and suppressed swelling ratio (9.26%), alongside a tensile strength of 19.14 MPa. The 6FPBI‐TP membrane exhibits a competitive OH ⁻ conductivity of 142.75 mS cm ^{− 1} at 80°C and an elevated selectivity of 67%. Its moderately hydrophobic, positively charged surface optimizes the three‐phase catalytic microenvironment, mitigating water flooding and suppressing the hydrogen evolution side reaction. In membrane electrode assembly, 6FPBI‐TP membrane delivers FE _CO of 94.4% at 150 mA cm ^{− 2} , exceeding OPBI‐TP membrane (89.1%). 6FPBI‐TP membrane maintains stable electrolysis over 100 h, while OPBI‐TP membrane fails after only 25 h. Molecular dynamics simulations reveal a dominant vehicular OH ⁻ transport pathway and enhanced alkaline stability derived from ether‐free fluorinated backbone. This dual cationic strategy not only constructs well‐defined ion transport channels but also modulates the interfacial microenvironment, thereby affording a straightforward route to AEM with high stability and high selectivity for ECR.

Biomass-derived hard carbon (BHC) with low-voltage plateau (LP) is a promising anode material for sodium ion batteries. However, conventional high-temperature carbonization is energy-intensive and inadequate rate capability, while low-temperature-derived BHC demonstrates insufficient LP contribution and low initial Coulombic efficiency (ICE), which hinder BHC practical applications. Herein, we developed a synergistic strategy of pyrolysis gas slow-release and heteroatom doping to tailor the architecture of BHCs. A nitrogen/sulfur dual-doped hard carbon (NS-HC) with ultralow specific surface area and centralized ultra-micropores (<0.7 nm) was synthesized at 750°C. This ultra-microporous architecture restricts electrolyte accessibility while enabling rapid Na+ diffusion and storage within the LP region. The experimental results and theoretical calculations indicate that heteroatom (N/S) doping not only enhances surface Na+ adsorption but also further improves the diffusion kinetics of the LP region by expanding the interlayer spacing. Consequently, the optimized NS-HC exhibits 80% ICE, reversible capacity of 304.3 mAh g−1 at 0.05 A g−1 (dominant LP contribution). Furthermore, the assembled full cell achieves high energy density of 212 Wh kg−1, and an "adsorption-intercalation/pore-filling" mechanism is revealed. This work provides a novel idea for the design and preparation of low-cost, high-performance BHC anode materials, and also offers a feasible pathway for the energy utilization of biomass.

The rapid development of flexible organic light‐emitting diode displays has intensified the demand for polyimide (PI) films with enhanced thermal and mechanical properties. In this study, a dibenzimidazole diamine monomer is synthesized, and a series of PI films are fabricated with the molar ratio of diamine monomer adjusted to optimize film performance. The optimized PI‐1 film exhibits a low coefficient of thermal expansion (5.0 ppm K⁻¹), high glass transition temperature (452 °C) and 5% weight loss temperature (550 °C), improved tensile strength (168 MPa) and a modulus of elasticity (5.2 GPa) that meet the requirements for flexible display applications. The findings of this study provide valuable guidance for fabricating advanced PI films based on monomer composition and rational molecular structural design.