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《Advanced Materials Interfaces》2017,4(16)
High voltage aqueous electrochemical energy storage devices have gained significant attention recently due to their high safety, low cost, and environmental friendliness. Through the addition of a solid‐electrolyte interphase, usage of a concentrated electrolyte or adjustment of the pH of their electrolytes, it is hopeful to endow these aqueous energy‐storage devices with a broadened voltage. Among all of them, aqueous lithium‐ion batteries have a longer lifespan and a promising future in energy storage systems. Herein, aqueous batteries will be introduced by demonstrating their voltage improvement approaches and progress is focused. 相似文献
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Nawishta Jabeen Ahmad Hussain Qiuying Xia Shuo Sun Junwu Zhu Hui Xia 《Advanced materials (Deerfield Beach, Fla.)》2017,29(32)
The voltage limit for aqueous asymmetric supercapacitors is usually 2 V, which impedes further improvement in energy density. Here, high Na content Birnessite Na0.5MnO2 nanosheet assembled nanowall arrays are in situ formed on carbon cloth via electrochemical oxidation. It is interesting to find that the electrode potential window for Na0.5MnO2 nanowall arrays can be extended to 0–1.3 V (vs Ag/AgCl) with significantly increased specific capacitance up to 366 F g?1. The extended potential window for the Na0.5MnO2 electrode provides the opportunity to further increase the cell voltage of aqueous asymmetric supercapacitors beyond 2 V. To construct the asymmetric supercapacitor, carbon‐coated Fe3O4 nanorod arrays are synthesized as the anode and can stably work in a negative potential window of ?1.3 to 0 V (vs Ag/AgCl). For the first time, a 2.6 V aqueous asymmetric supercapacitor is demonstrated by using Na0.5MnO2 nanowall arrays as the cathode and carbon‐coated Fe3O4 nanorod arrays as the anode. In particular, the 2.6 V Na0.5MnO2//Fe3O4@C asymmetric supercapacitor exhibits a large energy density of up to 81 Wh kg?1 as well as excellent rate capability and cycle performance, outperforming previously reported MnO2‐based supercapacitors. This work provides new opportunities for developing high‐voltage aqueous asymmetric supercapacitors with further increased energy density. 相似文献
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机械合金化Fe100—xNix系超细粉末的X射线衍射谱研究 总被引：6，自引：0，他引：6
用机械合金化方法制备了Ｆｅ１００－ｘＮｉｘ系超细粉末（其中ｘ＝７５,４５,３５,３２．５,３０）。对各样品进行了Ｘ－ｒａｙ衍射谱测量,用Ｓｃｈｅｒｒｅｒ方法测量了晶粒尺寸。用最小二乘法计算了随Ｎｉ含量ｘ的减少样品晶格常数的变化以及随Ｘ的减少样品的结构变化。发现当Ｘ＝７５．４５时,样品成为以Ｎｉ为溶剂Ｆｅ为溶质的面赠立方固溶体,随着Ｆｅ含量不断增加,Ｆｅ－Ｎｉ合金中除了Ｎｉ型面心立方结构外,还存在α 相似文献
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Yongting Qiu Mingzhen Hou Jingchang Gao Haili Zhai Haimin Liu Mengmeng Jin Xiang Liu Linfei Lai 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(45)
Cost‐effective synthesis of carbon nanospheres with a desirable mesoporous network for diversified energy storage applications remains a challenge. Herein, a direct templating strategy is developed to fabricate monodispersed N‐doped mesoporous carbon nanospheres (NMCSs) with an average particle size of 100 nm, a pore diameter of 4 nm, and a specific area of 1093 m2 g?1. Hexadecyl trimethyl ammonium bromide and tetraethyl orthosilicate not only play key roles in the evolution of mesopores but also guide the assembly of phenolic resins to generate carbon nanospheres. Benefiting from the high surface area and optimum mesopore structure, NMCSs deliver a large specific capacitance up to 433 F g?1 in 1 m H2SO4. The NMCS electrodes–based symmetric sandwich supercapacitor has an output voltage of 1.4 V in polyvinyl alcohol/H2SO4 gel electrolyte and delivers an energy density of 10.9 Wh kg?1 at a power density of 14014.5 W kg?1. Notably, NMCSs can be directly applied through the mask‐assisted casting technique by a doctor blade to fabricate micro‐supercapacitors. The micro‐supercapacitors exhibit excellent mechanical flexibility, long‐term stability, and reliable power output. 相似文献
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Lingfang Chen Jun Huang Rong Zeng Yushuai Xiong Junchao Wei Kai Yuan Yiwang Chen 《Advanced Materials Interfaces》2020,7(2)
Aqueous asymmetric supercapacitors (ASCs) are promising candidates for energy storage device because of their advanced merits of high power density, long cycling life, nontoxicity, and low cost. However, the energy density of the aqueous ASCs is still limited by the low operating voltage windows and the unmatchable capacitances of cathode and anode. Herein, pinecone‐like hollow Fe2O3/MnO2 nano‐heterostructures (Fe2O3/MnO2 NHs) cathode is developed with high potential window (0–1.2 V) and specific capacitance (297 F g−1 at 1 A g−1). Owing to the opposite operating voltage windows and similar capacitances value of the Fe2O3/MnO2 NHs as cathode and reduced graphene oxide/Fe2O3 (rGO/Fe2O3) aerogels as anode (−1.1 to 0 V, 274 F g−1 at 1 A g−1), the assembled Fe2O3/MnO2//rGO/Fe2O3 aqueous ASCs deliver a wide voltage window up to 2.4 V and a high energy density of 57.0 Wh kg−1. The as‐fabricated ASC also presents outstanding cycling stability (with 88.9% retention after 10 000 cycles at 10 A g−1) and well rate performance. Moreover, Fe2O3/MnO2//rGO/Fe2O3 all‐solid‐state ASC exhibits excellent voltage window (2.3 V), capacitance, and ratability. Thus, this study provides a novel approach for constructing high‐voltage aqueous ASC with high energy density. 相似文献
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Supercapacitors: A Hierarchical Carbon Derived from Sponge‐Templated Activation of Graphene Oxide for High‐Performance Supercapacitor Electrodes (Adv. Mater. 26/2016) 
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下载免费PDF全文 Jin Xu Ziqi Tan Wencong Zeng Guanxiong Chen Shuilin Wu Yuan Zhao Kun Ni Zhuchen Tao Mujtaba Ikram Hengxing Ji Yanwu Zhu 《Advanced materials (Deerfield Beach, Fla.)》2016,28(26):5331-5331
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《Advanced Materials Technologies》2017,2(3)
Stretchable energy storage devices are required to fit for stretchable electronic devices, forming a fully stretchable system for comfortable and body‐attachable electronic devices. Herein, highly stretchable micro‐supercapacitors are fabricated by designing wave‐shaped hybrid multiwalled carbon nanotubes/polyaniline electrodes. As‐fabricated stretchable devices exhibit a large areal capacitance of 44.13 mF cm−2 and offer a power density of 0.07 mW cm−2 at an area energy density of 0.004 mW h cm−2. Owing to the designed wavy electrode structure, the electrochemical performances of the stretchable micro‐supercapacitors are almost invariably under different stretching stations ranging from 5% to 40%. By fabricating stretchable micro‐supercapacitors arrays, a red light‐emitting diode can be easily lighted under different conditions including stretching, twisting, crimping, and winding. All these results confirm the outstanding stability and mechanical strength of stretchable micro‐supercapacitors, demonstrating its potential application in skin‐patchable electronics or portable/wearable devices. 相似文献
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Wei Guo Chang Yu Shaofeng Li Xuedan Song Huawei Huang Xiaotong Han Zhao Wang Zhibin Liu Jinhe Yu Xinyi Tan Jieshan Qiu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(28)
Defect engineering holds great promise for precise configuration of electrode materials for dramatically enhanced performance in the field of energy storage, but the high energy/large time cost and lack of control involved in this process represent a serious limit to its use. In response, a low‐energy‐cost and ultrafast universal converse voltage process is developed to effectively activate the capacitive performance of transition metal compounds integrated on carbon fiber paper, including Co‐, Ni‐, Mn‐, Fe‐, and Cr‐based hybrids. As a representative example, this process triggers a phase conversion from cobalt hydroxide to electric‐field‐activated CoOOH (EA‐CoOOH), leading to the formation of molecular structure with abundant defects, lattice disorders, and connecting holes, responsible for an enhanced performance within 10 min at room temperature. Moreover, the retained Co2+ in EA‐CoOOH results in increased activity, confirmed by density functional theory calculations. Consequently, these EA‐CoOOH hybrids deliver a capacitance value of 832 F g?1 at a current density of 1 A g?1 and exhibit a retention rate up to 78% (649 F g?1) at a super‐large current density of 200 A g?1. This technology paves a way for ultrafast configuration/modulation of defects on advanced materials toward application in the fields of energy and catalysis. 相似文献
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Weixing Song Jianxiong Zhu Baoheng Gan Shuyu Zhao Hui Wang Congju Li Jie Wang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(1)
The graphene with 3D porous network structure is directly laser‐induced on polyimide sheets at room temperature in ambient environment by an inexpensive and one‐step method, then transferred to silicon rubber substrate to obtain highly stretchable, transparent, and flexible electrode of the all‐solid‐state planar microsupercapacitors. The electrochemical capacitance properties of the graphene electrodes are further enhanced by nitrogen doping and with conductive poly(3,4‐ethylenedioxythiophene) coating. With excellent flexibility, stretchability, and capacitance properties, the planar microsupercapacitors present a great potential in fashionable and comfortable designs for wearable electronics. 相似文献
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Chueh Liu Changling Li Kazi Ahmed Zafer Mutlu Ilkeun Lee Francisco Zaera Cengiz S. Ozkan Mihrimah Ozkan 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(15)
Light‐weight graphite foam decorated with carbon nanotubes (dia. 20–50 nm) is utilized as an effective electrode without binders, conductive additives, or metallic current collectors for supercapacitors in aqueous electrolyte. Facile nitric acid treatment renders wide operating potentials, high specific capacitances and energy densities, and long lifespan over 10 000 cycles manifested as 164.5 and 111.8 F g?1, 22.85 and 12.58 Wh kg?1, 74.6% and 95.6% capacitance retention for 2 and 1.8 V, respectively. Overcharge protection is demonstrated by repetitive cycling between 2 and 2.5 V for 2000 cycles without catastrophic structural demolition or severe capacity fading. Graphite foam without metallic strut possessing low density (≈0.4–0.45 g cm?3) further reduces the total weight of the electrode. The thorough investigation of the specific capacitances and coulombic efficiencies versus potential windows and current densities provides insights into the selection of operation conditions for future practical devices. 相似文献
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Supercapacitors (SCs) have experienced a significant increase in research activity and commercialization during the past few decades. As the primary and most important electrode active material for commercial SCs, porous carbon is produced at an industrial‐scale through traditional carbonization‐activation strategies. Nevertheless, commercial porous carbon materials have some disadvantages such as high production cost, corrosion of equipment, and emission of toxic gases and byproduct pollutants during production. In recent years, huge efforts have been made to develop novel synthesis strategies for porous carbon materials. This review focuses on the pore formation mechanisms in traditional carbonization‐activation methods, emerging activation methods, template methods, self‐template methods, and novel emerging methods for the synthesis of porous carbons for SCs. Strategies developed so far for the synthesis of porous carbon materials are summarized. The mechanisms and recent advances for each strategy are reviewed. Furthermore, future directions and synthesis strategies for porous carbons are proposed. 相似文献
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Results are provided for international comparisons of a standard voltage transformer performed in Ukraine and Germany. Algorithms
are given for the equivalence of national standards taking account of expanded uncertainty.
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Translated from Izmeritel’naya Tekhnika, No. 11. pp. 57–58, November, 2007. 相似文献
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Wen Li Fengning Guo Haifeng Ling Hui Liu Mingdong Yi Peng Zhang Wenjun Wang Linghai Xie Wei Huang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(2)
In this paper, the development of organic field‐effect transistor (OFET) memory device based on isolated and ordered nanostructures (NSs) arrays of wide‐bandgap (WBG) small‐molecule organic semiconductor material [2‐(9‐(4‐(octyloxy)phenyl)‐9H‐fluoren‐2‐yl)thiophene]3 (WG3) is reported. The WG3 NSs are prepared from phase separation by spin‐coating blend solutions of WG3/trimethylolpropane (TMP), and then introduced as charge storage elements for nonvolatile OFET memory devices. Compared to the OFET memory device with smooth WG3 film, the device based on WG3 NSs arrays exhibits significant improvements in memory performance including larger memory window (≈45 V), faster switching speed (≈1 s), stable retention capability (>104 s), and reliable switching properties. A quantitative study of the WG3 NSs morphology reveals that enhanced memory performance is attributed to the improved charge trapping/charge‐exciton annihilation efficiency induced by increased contact area between the WG3 NSs and pentacene layer. This versatile solution‐processing approach to preparing WG3 NSs arrays as charge trapping sites allows for fabrication of high‐performance nonvolatile OFET memory devices, which could be applicable to a wide range of WBG organic semiconductor materials. 相似文献