Metal fibers have been widely used in many industrial applications due to their unique advantages. In certain applications, such as catalyst supports or orthopedic implants, a rough surface or tiny outshoots on the su...Metal fibers have been widely used in many industrial applications due to their unique advantages. In certain applications, such as catalyst supports or orthopedic implants, a rough surface or tiny outshoots on the surface of metal fibers to increase surface area are needed. However, it has not been concerned about the surface morphologies of metal fiber in the current research of metal fiber manufacturing. In this paper, a special multi-tooth tool composed of a row of triangular tiny teeth is designed. The entire cutting layer of multi-tooth tool bifurcates into several thin cutting layers due to tiny teeth involved in cutting. As a result, several stainless steel fibers with periodic micro-fins are produced simultaneously. Morphology of periodic micro-fins is found to be diverse and can be classified into three categories: unilateral plane, unilateral tapering and bilateral. There are two forming mechanisms for the micro-fins. One is that periodic burrs remained on the free side of cutting layer of a tiny tooth create micro-fins of stainless steel fiber produced by the next neighboring tiny tooth; the other is that the connections between two fibers stuck together come to be micro-fins if the two fibers are finally detached. Influence of cutting conditions on formation of micro-fins is investigated. Experimental results show that cutting depth has no significant effect on micro-fin formation, high cutting speed is conducive to micro-fin formation, and feed should be between 0.12 mm/r and 0.2 mm/r to reliably obtain stainless steel fiber with micro-fins. This research presents a new pattern of stainless steel fiber characterized by periodic micro-fins formed on the edge of fiber and its manufacturing method.展开更多
在微电子和微机械的高压应用中,如微型机器人、软致动器、皮肤电子、微型传感器和集成电子电路等,迫切需要高输出电压的储能/补给装置。近年来,高电压微型超级电容器(High voltage micro-supercapacitors,HVMSCs)因其微小型、便携式、...在微电子和微机械的高压应用中,如微型机器人、软致动器、皮肤电子、微型传感器和集成电子电路等,迫切需要高输出电压的储能/补给装置。近年来,高电压微型超级电容器(High voltage micro-supercapacitors,HVMSCs)因其微小型、便携式、柔韧性、高循环寿命及高功率/能量密度等优势而频繁作为功率补给装置应用到微机电系统,可满足一定范围的电压输出和能量供给,并且HVMSCs在电路中可作为储能器件应用可使电子产品更有可能趋向于集成式、高密度以及小型化。现有研究表明,增大MSCs的工作电压窗口,可以显著提升MSCs的输出能量密度,进而能最大限度地扩展其应用场合。因此,如何从材料、结构以及制造方法方面着手,制备全固态HVMSCs成为研究热点。基于此,首先对MSCs的电荷存储机制及电化学性能特征进行概述,其次分析高电压MSCs的实现原理,接着详细归纳HVMSCs的制造方法,主要包括高电压电极材料的制备(碳基材料、过渡金属氧化物、导电聚合物以及复合电极材料)以及高电压封装结构的制造(激光加工、喷墨打印、3D打印、丝网印刷、卷对卷印刷以及掩膜涂层),并且总结HVMSCs在储能功率器件、柔性传感以及可穿戴设施等方面的应用。在综合探讨HVMSCs的研究现状的基础上,最后对其在可穿戴和便携式电子设备等高电压领域的研究趋势和发展前景进行相应的展望。展开更多
An easy-to-implement method by which to fabricate superhydrophobic surfaces inspired taro leaf was successfully applied on316 L stainless steel via combining nanosecond laser(NL)processing and spin-coating techniques....An easy-to-implement method by which to fabricate superhydrophobic surfaces inspired taro leaf was successfully applied on316 L stainless steel via combining nanosecond laser(NL)processing and spin-coating techniques.The laser-textured surface composed of microscale frameworks and central bumps was fabricated by NL processing based on properly designed biomimetic patterns,and a layer of nanoscale carbon black/polydimethylsiloxane(CB/PDMS)particles was covered on it by spin-coating.The effect of pattern parameters(i.e.,the inscribed circle radius of framework and the radius of central bump)on wettability of biomimetic surface was investigated.All as-prepared biomimetic surfaces with micro-nano hierarchical structures showed excellent superhydrophobicity with the water contact angle of~155°and contact angle hysteresis of~2°.By comparing the untreated surface,the wetting behavior and evaporation mode of the biomimetic surface occurred an obvious transformation.Meanwhile,experiments indicated that the biomimetic surface not only had liquid-repelling and self-cleaning functions,but also maintained remarkable mechanical robustness and superhydrophobic durability.The method is efficient for fabricating biomimetic superhydrophobic surfaces applied to liquid-repelling,evaporation-transforming and self-cleaning fields.展开更多
The severe shuttle effect problem of soluble polysulfides greatly hinders the development of long-life lithium-sulfur(Li-S)batteries,which can be improved by separator modification.This study develops a bilayer separa...The severe shuttle effect problem of soluble polysulfides greatly hinders the development of long-life lithium-sulfur(Li-S)batteries,which can be improved by separator modification.This study develops a bilayer separator based on an effective surface and structure dual modification strategy.This bilayer separator(named as TCNFs/SPNFs)is constructed by the integration of a carbon-based nanofiber layer(surface modification layer)with a polymer-based nanofiber layer(structure modification layer)through a facile electrospinning process.The excellent electrolyte wettability of the nanofibers accelerates lithium-ion migration,while the good electronic conductivity of the carbon layer facilitates fast electron conduction.The TiO_(2)and SiO_(2)nanoparticles embedded in the separator provide abundant active sites for immobilizing the polysulfides.Owing to these synergistic effects,this multi-functional separator helps inhibit the shuttling problem and thus enhances the active sulfur utilization.The as-prepared battery with the TCNFs/SPNFs separator delivers significantly enhanced the electrochemical performances,producing a low capacity decay rate of 0.061%per cycle at 1 C over 1000 cycles and an admirable rate capacity of 886.7 mAh g^(-1)at 2 C.Even with a high sulfur loading of 4.8 mg cm^(-2),a remarkable areal capacity of 6.0 mAh cm^(-2)is attained.This work is believed to provide a promising strategy to develop novel separators for high-performance Li-S batteries.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51375176)Guangdong Provincial Natural Science Foundation of China(Grant No.2014A030313264)Fundamental Research Funds for the Central Universities,SCUT,China(Grant No.2013ZZ017)
文摘Metal fibers have been widely used in many industrial applications due to their unique advantages. In certain applications, such as catalyst supports or orthopedic implants, a rough surface or tiny outshoots on the surface of metal fibers to increase surface area are needed. However, it has not been concerned about the surface morphologies of metal fiber in the current research of metal fiber manufacturing. In this paper, a special multi-tooth tool composed of a row of triangular tiny teeth is designed. The entire cutting layer of multi-tooth tool bifurcates into several thin cutting layers due to tiny teeth involved in cutting. As a result, several stainless steel fibers with periodic micro-fins are produced simultaneously. Morphology of periodic micro-fins is found to be diverse and can be classified into three categories: unilateral plane, unilateral tapering and bilateral. There are two forming mechanisms for the micro-fins. One is that periodic burrs remained on the free side of cutting layer of a tiny tooth create micro-fins of stainless steel fiber produced by the next neighboring tiny tooth; the other is that the connections between two fibers stuck together come to be micro-fins if the two fibers are finally detached. Influence of cutting conditions on formation of micro-fins is investigated. Experimental results show that cutting depth has no significant effect on micro-fin formation, high cutting speed is conducive to micro-fin formation, and feed should be between 0.12 mm/r and 0.2 mm/r to reliably obtain stainless steel fiber with micro-fins. This research presents a new pattern of stainless steel fiber characterized by periodic micro-fins formed on the edge of fiber and its manufacturing method.
文摘在微电子和微机械的高压应用中,如微型机器人、软致动器、皮肤电子、微型传感器和集成电子电路等,迫切需要高输出电压的储能/补给装置。近年来,高电压微型超级电容器(High voltage micro-supercapacitors,HVMSCs)因其微小型、便携式、柔韧性、高循环寿命及高功率/能量密度等优势而频繁作为功率补给装置应用到微机电系统,可满足一定范围的电压输出和能量供给,并且HVMSCs在电路中可作为储能器件应用可使电子产品更有可能趋向于集成式、高密度以及小型化。现有研究表明,增大MSCs的工作电压窗口,可以显著提升MSCs的输出能量密度,进而能最大限度地扩展其应用场合。因此,如何从材料、结构以及制造方法方面着手,制备全固态HVMSCs成为研究热点。基于此,首先对MSCs的电荷存储机制及电化学性能特征进行概述,其次分析高电压MSCs的实现原理,接着详细归纳HVMSCs的制造方法,主要包括高电压电极材料的制备(碳基材料、过渡金属氧化物、导电聚合物以及复合电极材料)以及高电压封装结构的制造(激光加工、喷墨打印、3D打印、丝网印刷、卷对卷印刷以及掩膜涂层),并且总结HVMSCs在储能功率器件、柔性传感以及可穿戴设施等方面的应用。在综合探讨HVMSCs的研究现状的基础上,最后对其在可穿戴和便携式电子设备等高电压领域的研究趋势和发展前景进行相应的展望。
基金the National Key Research and Development Program of China(Grant No.2019YFE0126300)the National Natural Science Foundation of China(Grant No.51775197)the Natural Science Foundation of Guangdong Province(Grant No.2019A1515011530)。
文摘An easy-to-implement method by which to fabricate superhydrophobic surfaces inspired taro leaf was successfully applied on316 L stainless steel via combining nanosecond laser(NL)processing and spin-coating techniques.The laser-textured surface composed of microscale frameworks and central bumps was fabricated by NL processing based on properly designed biomimetic patterns,and a layer of nanoscale carbon black/polydimethylsiloxane(CB/PDMS)particles was covered on it by spin-coating.The effect of pattern parameters(i.e.,the inscribed circle radius of framework and the radius of central bump)on wettability of biomimetic surface was investigated.All as-prepared biomimetic surfaces with micro-nano hierarchical structures showed excellent superhydrophobicity with the water contact angle of~155°and contact angle hysteresis of~2°.By comparing the untreated surface,the wetting behavior and evaporation mode of the biomimetic surface occurred an obvious transformation.Meanwhile,experiments indicated that the biomimetic surface not only had liquid-repelling and self-cleaning functions,but also maintained remarkable mechanical robustness and superhydrophobic durability.The method is efficient for fabricating biomimetic superhydrophobic surfaces applied to liquid-repelling,evaporation-transforming and self-cleaning fields.
基金supported by the National Natural Science Foundation of China(Grant Nos.51975218 and U22A20193)the Natural Science Foundation of Guangdong Province(Grant No.2021A1515010642)+3 种基金Guangdong-Hong Kong Joint Innovation Project of Guangdong Province(Grant No.2021A0505110002)Guangdong-Foshan Joint Foundation(Grant No.2021B1515120031)the Innovation Group Project of Foshan(Grant No.2120001010816)the S&T Innovation Projects of Zhuhai City(Grant No.ZH01110405180034PWC)。
文摘The severe shuttle effect problem of soluble polysulfides greatly hinders the development of long-life lithium-sulfur(Li-S)batteries,which can be improved by separator modification.This study develops a bilayer separator based on an effective surface and structure dual modification strategy.This bilayer separator(named as TCNFs/SPNFs)is constructed by the integration of a carbon-based nanofiber layer(surface modification layer)with a polymer-based nanofiber layer(structure modification layer)through a facile electrospinning process.The excellent electrolyte wettability of the nanofibers accelerates lithium-ion migration,while the good electronic conductivity of the carbon layer facilitates fast electron conduction.The TiO_(2)and SiO_(2)nanoparticles embedded in the separator provide abundant active sites for immobilizing the polysulfides.Owing to these synergistic effects,this multi-functional separator helps inhibit the shuttling problem and thus enhances the active sulfur utilization.The as-prepared battery with the TCNFs/SPNFs separator delivers significantly enhanced the electrochemical performances,producing a low capacity decay rate of 0.061%per cycle at 1 C over 1000 cycles and an admirable rate capacity of 886.7 mAh g^(-1)at 2 C.Even with a high sulfur loading of 4.8 mg cm^(-2),a remarkable areal capacity of 6.0 mAh cm^(-2)is attained.This work is believed to provide a promising strategy to develop novel separators for high-performance Li-S batteries.
