摘要：Aqueous Zn-iodine(Zn-I_(2))batteries have attracted extensive research interest as an emerging redox conversion energy storage system due to the low cost and high ***,the shuttling effects of polyiodides arising from incomplete redox conversion and inhomogeneous Zn plating on the Zn anode surface always hinder the commercial application of Zn-I_(2)*** this work,a two-birds-with-one-stone strategy is reported for long-life Zn-I_(2)*** on the strategy,the sulfonate-functionalized carbon fiber not only acts as the excellent iodine limiter to inhibit iodine species shuttling,but also as the uniform Zn plating guidance layer on the Zn anode surface to prevent the inhomogeneous deposition of Zn^(2+).Consequently,a superior cycling stability(a capacity of 124 mAh g^(-1)after 10,000 cycles at 5 A g^(-1))is *** calculations illustrate that sulfonate groups successfully induce charge redistribution on the carbon substrate,thereby strengthening the electronic interactions of the iodine species with the carbon *** charge-enriched sulfonate groups can guide the uniform deposition of Zn^(2+)through a strong Coulombic effect with Zn^(2+).This work gives a new perspective on the integrated design of cathodes and anodes for rechargeable batteries.

摘要：聚环氧乙烷(PEO)聚合物电解质有望应用于全固态锂金属电池.然而,目前还没有提出有效的方法制备全固态PEO电解质,以克服其在室温下无法使用的局限性.在本研究中,我们基于聚合物C-H键功能化策略,通过在聚合物链上直接共价连接具有锂配位活性的丁二腈官能团,设计出了一种高离子导电性PEO电解质.该官能团有效增强了PEO链的无序性和流动性,同时也作为链间快速离子传导的活性位点,从而实现了离子周围自由体积和迁移行为的双重优化.得益于官能团对离子输运的精准调节,新型电解质表现出更强的离子传导性(离子电导率提升100倍)、更高的转移数(tLi+=0.51)和更宽的电化学窗口(>0.47 V).特别是功能化的PEO300k电解质具有超高室温离子电导率(25℃时为1.01×10^(-4)S cm^(-1))并且能够在室温下稳定工作,该研究为开发具有实际应用价值的聚合物电解质提供了新的途径.

摘要：大功率多电平逆变器近年来在实际工业生产中得到越来越广泛的应用。多电平逆变器由于结构复杂,采用元器件较多,因此在设计和实验中,实现各个工作状态下运行参数的同步监测和分析较为困难。本文针对大功率三电平逆变器,实现开关动态特性的在线测试,在此基础上,进一步研究三电平逆变器在开关状态变化时理论与实际负载运行工况下电路拓扑的转换变化规律。通过全电路电气参数和元器件状态的实时监测,发现在三电平逆变器非正常运行状态下开关转换时额外电应力,同时,深入研究在实际工况运行条件非正常状态下该额外电应力出现的机理和原因,为三电平逆变器的故障诊断提供了参考,对于设计高可靠性的多电平逆变器系统有一定的理论和现实意义。

摘要：A kind of closed-loop Hall effect sensor is designed and fabricated by considering several factors such as iron core material, Hall device, as well as selected integrated circuit. Through studying the effect of the iron material and structures of current sensor, a kind of optimal Hall effect current sensor is found. The experimental results show that the presented closed-loop Hall effect current sensor achieves 1 mA/A sensitivity. And its lineafity and accuracy are 0.1% and 0.35% FS, respectively, at cur- rents ranging from 0 to 50 A.

摘要：Cu-based catalysts are the most promising candidates for electrochemical CO_(2)reduction(CO_(2)RR)to multi-carbon(C_(2))*** the C-C coupling process,the rate-determining step for C_(2)product generation,is an important strategy to improve the production and selectivity of the C_(2)*** this study,we determined that the local electric field can promote the C-C coupling reaction and enhance CO_(2)electroreduction to C_(2)***,finite-element simulations indicated that the high curvature of the Cu nanoneedles results in a large local electric field on their *** functional theory(DFT)calculations proved that a large electric field can promote C-C *** by this prediction,we prepared a series of Cu catalysts with different *** Cu nanoneedles(NNs)exhibited the largest number of curvatures,followed by the Cu nanorods(NRs),and Cu nanoparticles(NPs).The Cu NNs contained the highest concentration of adsorbed K+,which resulted in the highest local electric field on the *** adsorption sensor tests indicated that the Cu NNs exhibited the strongest CO adsorption ability,and in-situ Fourier-transform infrared spectroscopy(FTIR)showed the strongest*COCO and*CO signals for the Cu *** experimental results demonstrate that high-curvature nanoneedles can induce a large local electric field,thus promoting C-C *** a result,the Cu NNs show a maximum FEC_(2)of 44%for CO_(2)RR at a low potential(-0.6 V ***),which is approximately 2.2 times that of the Cu *** work provides an effective strategy for enhancing the production of multi-carbon products during CO_(2)RR.

摘要：An orthogonal experiment scheme was designed to investigate the effects of the Cu content,compaction pressure,and sintering temperature on the microstructures and mechanical and thermal properties of(30−50)wt.%Cu/Invar bi-metal matrix composites fabricated via spark plasma sintering(SPS).The results indicated that as the Cu content increased from 30 to 50 wt.%,a continuous Cu network gradually appeared,and the density,thermal conductivity(TC)and coefficient of thermal expansion of the composites noticeably increased,but the tensile strength *** increase in the sintering temperature promoted the Cu/Invar interface diffusion,leading to a reduction in the TC but an enhancement in the tensile strength of the *** compaction pressure comprehensively affected the thermal properties of the *** 50wt.%Cu/Invar composite sintered at 700℃ and 60 MPa had the highest TC(90.7 W/(m·K)),which was significantly higher than the TCs obtained for most of the previously reported Cu/Invar composites.

摘要：钾离子电池(PIBs)面临的一个关键问题是设计具有先进结构的负极材料,以实现快速电荷传输以提高钾的存储性能.采用碳二亚胺铁(FeNCN)作为阳极,由于其含有一定数量的共价键且在分子水平上具有稳定的结构,使得储钾系统能够实现优异的电化学性能.FeNCN阳极具有高导电性,带隙接近0 eV,并且由于其共价键结构具有良好的结构稳定性.此外,无定形反应产物也为离子扩散提供了多种途径.因此,FeNCN阳极表现出高可逆比容量(在50 mA g^(-1)电流密度下具有600 mA h g^(-1)比容量),显著的倍率性能和长寿命循环(电流密度为500 mA g^(-1)时拥有400 mA h g^(-1)比容量且超过300次循环).通过理论模拟、X射线原位衍射分析和X射线光电子能谱分析揭示了Fe^(2+)和K^(+)之间的转化反应机理.此外,将FeNCN负极与苝-3,4,9,10-四羧酸二酐正极材料匹配,组装成的全电池在198.6 Wkg^(-1)的功率密度下实现了184.7 W h kg^(-1)的超高能量密度,明显高于以往所有铁基负极的PIBs或钾离子混合电容器.