Utilization of solar energy is of great interest for a sustainable society, and its conversion into electricity in a compact battery is challenging. Herein, a zinc–air battery with the polymer semiconductor polytrithiophene (pTTh) as the cathode is reported for direct conversion of photoenergy into electric energy. Upon irradiation, photoelectrons are generated in the conduction band (CB) of pTTh and then injected into the π2p* orbitals of O2 for its reduction to HO2?, which is disproportionated to OH? and drives the oxidation of Zn to ZnO at the anode. The discharge voltage was significantly increased to 1.78 V without decay during discharge–charge cycles over 64 h, which corresponds to an energy density increase of 29.0 % as compared to 1.38 V for a zinc–air battery with state‐of‐the‐art Pt/C. The zinc–air battery with an intrinsically different reaction scheme for simultaneous conversion of chemical and photoenergy into electric energy opens a new pathway for utilization of solar energy. 相似文献
A novel capacitor with high dielectric constant (ε) has been developed by blending poly(vinylidene fluoride) (PVDF) with polyamide (PA11). The blends show high dielectric constants (εblend = 40), which give better frequency stability (1 MHz), and excellent mechanical properties. Based on certain volume fractions, the measured dielectric constants (ε blend ) were found to exceed those of the corresponding polymers, in contrasted to conventional composites, where εpolymerA < εcomposite < εpolymerB. SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial polymer‐polymer interactions. DSC and XRD demonstrate that blending PA11 with PVDF affects the crystalline behavior of each component. However, the PA11/PVDF blends exhibit a slightly high dielectric loss (tanδ ≈ 0.17), which is a great disadvantage to a capacitor. Adding a copolymer of styrene and maleic anhydride decreased the dielectric loss (tanδ ≈ 0.057) and increased the dielectric constant (εblend = 60). Our findings suggest that the high‐ε polymeric blends created represent a novel type of material that is flexible and easy to process, of relatively high dielectric constant, of high breakdown strength and, moreover, is suited to applications in flexible electronics.
The TiO2/BiOI heterostructured nanofibers were prepared by electrospinning–solvothermal two-step process. The BiOI nanosheets, which owned a thickness of tens of nanometers and an average side length of about 300 nm, were intensive and crossed arranging on the TiO2 nanofibers whose diameter was about 400–550 nm and length was about 15–45 μm. The absorption edge of TiO2/BiOI heterostructured nanofibers was extended to more than 600 nm in visible-light region and the TiO2/BiOI exhibited enhanced visible-light photocatalytic performance and excellent recyclability compared to the individual TiO2 nanofibers and the BiOI microflowers in the photodecomposition of methylene blue, which was ascribed to nanoscale size heterostructure, narrow energy band, peculiar band gap structures, and porous surface structure. 相似文献
The LiNi0.8Co0.1Mn0.1O2 with LiAlO2 coating was obtained by hydrolysis–hydrothermal method. The morphology of the composite was characterized by SEM, TEM, and EDS. The results showed that the LiAlO2 layer was almost completely covered on the surface of particle, and the thickness of coating was about 8–12 nm. The LiAlO2 coating suppressed side reaction between composite and electrolyte; thus, the electrochemical performance of the LiAlO2-coated LiNi0.8Co0.1Mn0.1O2 was improved at 40 °C. The LiAlO2-coated sample delivered a high discharge capacity of 181.2 mAh g?1 (1 C) with 93.5% capacity retention after 100 cycles at room temperature and 87.4% capacity retention after 100 cycles at 40 °C. LiAlO2-coated material exhibited an excellent cycling stability and thermal stability compared with the pristine material. These works will contribute to the battery structure optimization and design. 相似文献
(Ni0.8Mn0.1Co0.1)(OH)2 and Co(OH)2 secondly treated by LiNi0.8Mn0.1Co0.1O2 have been prepared via co-precipitation and high-temperature solid-state reaction. The residual lithium contents, XRD Rietveld refinement, XPS, TG-DSC, and electrochemical measurements are carried out. After secondly treating process, residual lithium contents decrease drastically, and occupancy of Ni in 3a site is much lower and Li/Ni disorder decreases. The discharge capacity is 193.1, 189.7, and 182 mAh g?1 at 0.1 C rate, respectively, for LiNi0.8Mn0.1Co0.1O2-AP, -NT, and -CT electrodes between 3.0 and 4.2 V in pouch cell. The capacity retention has been greatly improved during gradual capacity fading of cycling at 1 C rate. The noticeably improved thermal stability of the samples after being treated can also be observed. 相似文献
Kinetic control over structures and functions of complex assembly systems has aroused widespread interest. Understanding the complex pathway and transient intermediates is helpful to decipher how multiple components evolve into complex assemblies. However, for supramolecular polymerizations, thorough and quantitative kinetic analysis is often overlooked. Challenges remain in collecting the information of structure and content of transient intermediates in situ with high temporal and spatial resolution. Here, the unsolved evolution mechanism of a classical self-sorting supramolecular copolymerization system was addressed by employing multidimensional NMR techniques coupled with a microfluidic technique. Unexpected complex pathways were revealed and quantitatively analyzed. A counterintuitive pathway involving polymerization through the ‘error-correction’ of non-polymerizable transient intermediates was identified. Moreover, a ‘non-classical’ step-growth polymerization process controlled by the self-sorting mechanism was unraveled based on the kinetic study. Realizing the existence of transient intermediates during self-sorting can encourage the exploitation of this strategy to construct kinetic steady state assembly systems. Moreover, the strategy of coupling a microfluidic technique with various characterization techniques can provide a kinetic analysis toolkit for versatile assembly systems. The combined approach of coupling thermodynamic and kinetic analyses is indispensable for understanding the assembly mechanisms, the rules of emergence, and the engineering of complex assembly systems.Polymerization through the ‘error-correction’ of non-polymerizable transient intermediates was identified in a classical self-sorting supramolecular copolymerization system by employing NMR coupled with a microfluidic technique.相似文献
Organic electrode materials suffer from low electronic conductivity and poor structure stability. Herein, a metal–organic polymer, Ni-coordinated tetramino-benzoquinone (Ni-TABQ), is synthesized via d–π hybridization. The polymer chains are stitched by hydrogen bonds to feature as a robust two-dimensional (2D) layered structure. It offers both electron conduction and Na+ diffusion pathways along the directions of the polymer chains and the hydrogen bonds. With both the conjugated benzoid carbonyls and imines as the redox centers for the insertion and extraction of Na+, the Ni-TABQ delivers high capacities of about 469.5 mAh g−1 at 100 mA g−1 and 345.4 mAh g−1 at 8 A g−1. The large capacities are sustained for 100 cycles with almost 100 % coulombic efficiencies. The exceptional electrochemical performance is attributed to the unique 2D electron conduction and Na+ diffusion pathways enabled by the robust Ni–N and hydrogen bonds. 相似文献