Although the proton exchange membrane fuel cell (PEMFC) has made great progress in recent decades, its commercialization has been hindered by a number of factors, among which is the total dependence on Pt‐based catalysts. Alkaline polymer electrolyte fuel cells (APEFCs) have been increasingly recognized as a solution to overcome the dependence on noble metal catalysts. In principle, APEFCs combine the advantages of and alkaline fuel cell (AFC) and a PEMFC: there is no need for noble metal catalysts and they are free of carbonate precipitates that would break the waterproofing in the AFC cathode. However, the performance of most alkaline polyelectrolytes can still not fulfill the requirement of fuel cell operations. In the present work, detailed information about the synthesis and physicochemical properties of the quaternary ammonia polysulfone (QAPS), a high‐performance alkaline polymer electrolyte that has been successfully applied in the authors' previous work to demonstrate an APEFC completely free from noble metal catalysts (S. Lu, J. Pan, A. Huang, L. Zhuang, J. Lu, Proc. Natl. Acad. Sci. USA 2008, 105, 20611), is reported. Monitored by NMR analysis, the synthetic process of QAPS is seen to be simple and efficient. The chemical and thermal stability, as well as the mechanical strength of the synthetic QAPS membrane, are outstanding in comparison to commercial anion‐exchange membranes. The ionic conductivity of QAPS at room temperature is measured to be on the order of 10−2 S cm−1. Such good mechanical and conducting performances can be attributed to the superior microstructure of the polyelectrolyte, which features interconnected ionic channels in tens of nanometers diameter, as revealed by HRTEM observations. The electrochemical behavior at the Pt/QAPS interface reveals the strong alkaline nature of this polyelectrolyte, and the preliminary fuel cell test verifies the feasibility of QAPS for fuel cell applications.

A metallic nanoparticle-decorated ceramic anode was prepared by in situ reduction of the perovskite Sr2FeMo0.65Ni0.35O6-δ (SFMNi) in H2 at 850 °C. The reduction converts the pure perovksite phase into mixed phases containing the Ruddlesden-Popper structure Sr3FeMoO7-δ, perovskite Sr(FeMo)O3-δ, and the FeNi3 bimetallic alloy nanoparticle catalyst. The electrochemical performance of the SFMNi ceramic anode is greatly enhanced by the in situ exsolved Fe-Ni alloy nanoparticle catalysts that are homogeneously distributed on the ceramic backbone surface. The maximum power densities of the La0.8Sr0.2Ga0.8Mg0.2O3-δ electrolyte supported a single cell with SFMNi as the anode reached 590, 793, and 960 mW cm(-2) in wet H2 at 750, 800, and 850 °C, respectively. The Sr2FeMo0.65Ni0.35O6-δ anode also shows excellent structural stability and good coking resistance in wet CH4. The prepared SFMNi material is a promising high-performance anode for solid oxide fuel cells.

In this work, we investigated in detail the structural characteristics of mixtures of choline chloride and urea with different urea contents by performing molecular dynamic (MD) simulations, and offer possible explanations for the low melting point of the eutectic mixture of choline chloride and urea with a ratio of 1:2. The insertion of urea molecules was found to change the density distribution of cations and anions around the given cations significantly, disrupting the long-range ordered structure of choline chloride. Moreover, with increasing urea concentration, the hydrogen bond interactions between choline cations and Cl − anions decreased, while those among urea molecules obviously increased. From the hydrogen bond lifetimes, it was found that a ratio of 1:2 between choline chloride and urea is necessary for a reasonable strength of hydrogen bond interaction to maintain the low melting point of the mixture of choline chloride with urea. In addition, it was also deduced from the interaction energies that a urea content of 67.7 % may make the interactions of cation-anion, cation-urea and anion-urea modest, and thus results in the lower melting point of the eutectic mixture of choline chloride and urea. The present results may offer assistance to some extent for understanding the physicochemical properties of the eutectic mixture of choline chloride and urea, and give valuable information for the further development and application of deep eutectic solvents.

Potassium-ion hybrid capacitors (PIHCs) shrewdly combine a battery-type anode and a capacitor-type cathode, exhibiting an energy density close to that of potassium ion batteries and a comparable power density of supercapacitors. However, the rosy scenario is compromised by the sluggish kinetics in the PIHCs device. Herein, the kinetics enhanced nitrogen-doped hierarchical porous hollow carbon spheres (NHCS) are synthesized and successfully applied to PIHCs. As for the K half-cell, NHCS anchored with sodium alginate delivers excellent electrochemical performance. Further evaluation shows that the binder can significantly affect the potassium storage performance of NHCS by adjusting the coatability and ionic conductivity of the NHCS anode. Moreover, kinetic analysis and density functional theory calculations reveal the origin of the superior electrochemical properties of NHCS. As expected, an advanced PIHC device is assembled with a NHCS anode and an activated NHCS cathode, demonstrating an exceptionally high energy/power density (114.2 Wh kg −1 and 8203 W kg −1 ), along with a long-life capability. The successful construction of high-performance PIHCs in this work opens a new avenue for the development and application of PIHCs in the future.

The effect of LiF 2 BC 2 O 4 (LiDFOB) electrolyte additive on the capacity and impedance characteristics of cells with Li 1.2 Ni 0.15 Mn 0.55 Co 0.1 O 2 -based positive, graphite-based negative and LiPF 6 -based electrolyte is evaluated using a combination of electrochemical cycling and surface analysis techniques. The impedance rise in these cells occurs primarily at the positive electrode whereas the capacity loss results from lithium trapping at the negative electrode. The LiDFOB serves as a bifunctional additive and reduces both cell capacity loss and impedance rise by reacting at both electrodes; probable reaction mechanisms have been highlighted in this article. X-ray photoelectron spectroscopy (XPS) data show that the LiDFOB additive forms a thicker passivation layer that inhibits electrolyte oxidation and reduces dissolution of Mn, Ni, Co ions from the positive electrode. Secondary ion mass spectroscopy (SIMS) data show that a thinner but more robust SEI forms at the negative electrode, which helps maintain cell capacity. The synergistic effects of LiDFOB at both electrodes results in a marked improvement in cell electrochemical performance.