Yuping Li

Traditional carbon-based materials suffer from fragility, low mechanical strength, and electrical conductivity when they are used as a gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs), resulting in low power density. In this study, a flexible carbon nanofiber membrane (CFM) was studied for use as a GDL, prepared by polyacrylonitrile (PAN) electrospinning with the incorporation of carboxylated multiwalled carbon nanotubes (MWCNTs), polyethylenimine (PEI) impregnation, glutaraldehyde (GA) cross-linking, and thermal treatment. The concentrations of MWCNTs in the electrospinning solution and PEI in the impregnation solution were investigated. Interestingly, the mechanical strength and electrical conductivity of CFM showed a triangle trend with the MWCNTs or PEI concentration. The optimal sample (CNT1.5/PEI7/GA-CFM) demonstrated good flexibility, with an in-plane resistivity of 18.60 mΩ cm, a tensile strength of 7.94 MPa, and a bending strength of 20.65 MPa. The peak power density and maximum current density were respectively 1169 mW cm^-2 and 2720 mA cm^-2, exceeding those of commercial Toray and Cetech GDLs under identical testing conditions. These results illustrate the potential of high-performance electrospun CFMs for GDL applications.

The development of high capacity and stable cathodes is the key to the successful commercialization of aqueous zinc-ion batteries. However, significant solvation penalties limit the choice of available positive electrodes. Herein, hydrated intercalation is proposed to promote reversible (de)intercalation within host materials by rationally designing a matching electrode. In contrast to previously reported works, the as-prepared electrode ([email protected]) can achieve fast and reversible intercalation of hydrated zinc ions in the interlayer gap, leading to a high capacity of 517 mAh g^–1 at 0.1 A g^–1 and excellent electrode stability for long-term cycling. Besides, as a consequence of the flexibility of the [email protected] electrode, a quasi-solid-state battery was achieved with equally advantageous electrochemical behavior under various bending states. The proposed hydrated cation direct insertion/extraction sets up an efficient way of developing high-performance positive electrodes for aqueous batteries.

A multi-objective optimal scheduling strategy for regional integrated power and heat energy system (RIPHES) considering adjustable heat load (AHL) is proposed in this paper. Firstly, based on the introduction of the basic architecture and characteristics of RIPHES, the component unit models of RIPHES are established. Secondly, the electric energy balance constraint and heat energy balance constraint of RIPHES are set. Then the multi-objective function based on multi-scene optimization operation requirement is established, including energy conservation target, absorption target and emission reduction target. Finally, an integrated multi-objective optimization scheduling model for RIPHES is established, and the effectiveness and feasibility of the model and strategy are verified by example simulation and analysis. The proposed model and strategy can effectively save primary fossil energy, promote new energy consumption and reduce carbon emissions, which can provide theoretical support for the modelling and optimization of key technologies in integrated energy systems.

Nutrients carried in upstream rivers to lakes are the main cause of eutrophication. Building near-natural estuarine wetlands between rivers and lakes is an effective way to remove pollutants and restore the ecology of estuarine areas. However, for the existing estuarine wetland ecological restoration projects, there is a lack of corresponding evaluation methods and index systems to make a comprehensive assessment of their restoration effects. By summarizing a large amount of literature and doing field research, an index system was constructed by combining the characteristics of the near-natural estuarine wetlands themselves. It covered environmental benefits, technical management and maintenance, and socio-economic functions, and contained 3 systems, 7 criteria, and 16 indicators. The analytical hierarchy process (AHP) was used to determine the weights of each indicator. The top 5 indicators in order of importance were habitat diversity, total phosphorus (TP), coverage of aquatic plants, ammonia nitrogen (NH₃-N), and adaptation to the surrounding landscape. The above evaluation system was used for the comprehensive evaluation of the water purification project in the Fuhe estuarine wetland, Hebei Province, as an example. The results showed that the comprehensive score of the Fuhe estuarine wetland at this stage was 4.1492, and the evaluation grade was excellent. The effect of water purification and ecological restoration was good, and the selected technology was suitable and stable in operation. It had a greater positive impact on the surrounding economy and society and can be promoted and applied. The research results were important for clarifying the advantages and defects of the project and developing efficient and advanced restoration technologies.

Non-carbon materials in capacitive deionization (CDI) can help to enhance the capacity of removed ions. Here, we report for the first time the removal of chloride ions (Cl⁻) with a bismuth (Bi) anode when coupled with an activated carbon (AC) cathode in CDI. The effects of carbon black in the Bi electrode, applied voltage, electrode mass loading and initial concentration on Cl⁻ removal are investigated. Moreover, its cycle performance is also tested. Results show that addition of carbon black to a Bi electrode (Bi@CB) significantly improves Cl⁻ removal. The declining trend of Cl⁻ concentration and appearance of peaks assigned to products of bismuth oxychloride (BiOCl) in XRD patterns confirm Cl⁻ storage by the Bi electrode, which is enhanced with an increase in voltage. When coupled with AC in a fixed mass, increasing the Bi mass does not contribute to more Cl⁻ removal. Although the cycle performance is not excellent (the attenuation rate is 74% after 10 cycles), its chloride removal capacity is ∼2–3 times the value of AC (e.g. 0.95 vs. 0.32 mmol g_Bi ⁻¹ at 1.2 V in 500 mg L⁻¹ NaCl solution). Besides, the Bi–AC electrode pair in CDI is more suitable to remove Cl⁻ from a solution with a Cl⁻ concentration of below 600 mg L⁻¹.

We report in this study a scalable and controllable approach for fabricating robust and high-performance superhydrophobic membranes for membrane distillation (MD). This novel approach combines electro-co-spinning/spraying (ES2) with chemical vapor welding, and enables the formation of robust superhydrophobic (r-SH) membranes that are mechanically strong, highly porous, and robustly superhydrophobic. Compared with superhydrophobic membranes obtained using surface deposition of fluorinated nanoparticles, the r-SH membranes have more robust wetting properties and higher vapor permeability in MD. MD scaling experiments with NaCl and gypsum show that the r-SH membrane is highly effective in mitigating mineral scaling. Finally, we also discuss the mechanism of scaling resistance enabled by superhydrophobic membranes with a highlight on the roles of the surface-bound air layer in reducing the crystal-membrane contact area, nucleation propensity, and ion-membrane contact time.