共查询到20条相似文献,搜索用时 31 毫秒
1.
Yusen Zhao Yousif Alsaid Bowen Yao Yucheng Zhang Bozhen Zhang Neel Bhuskute Shuwang Wu Ximin He 《Advanced functional materials》2020,30(10)
Oriented microstructures are widely found in various biological systems for multiple functions. Such anisotropic structures provide low tortuosity and sufficient surface area, desirable for the design of high‐performance energy storage devices. Despite significant efforts to develop supercapacitors with aligned morphology, challenges remain due to the predefined pore sizes, limited mechanical flexibility, and low mass loading. Herein, a wood‐inspired flexible all‐solid‐state hydrogel supercapacitor is demonstrated by morphologically tuning the aligned hydrogel matrix toward high electrode‐materials loading and high areal capacitance. The highly aligned matrix exhibits broad morphological tunability (47–12 µm), mechanical flexibility (0°–180° bending), and uniform polypyrrole loading up to 7 mm thick matrix. After being assembled into a solid‐state supercapacitor, the areal capacitance reaches 831 mF cm?2 for the 12 µm matrix, which is 259% times of the 47 µm matrix and 403% times of nonaligned matrix. The supercapacitor also exhibits a high energy density of 73.8 µWh cm?2, power density of 4960 µW cm?2, capacitance retention of 86.5% after 1000 cycles, and bending stability of 95% after 5000 cycles. The principle to structurally design the oriented matrices for high electrode material loading opens up the possibility for advanced energy storage applications. 相似文献
2.
Mingchao Wang Huanhuan Shi Panpan Zhang Zhongquan Liao Mao Wang Haixia Zhong Friedrich Schwotzer Ali Shaygan Nia Ehrenfried Zschech Shengqiang Zhou Stefan Kaskel Renhao Dong Xinliang Feng 《Advanced functional materials》2020,30(30)
2D conjugated metal‐organic frameworks (2D c‐MOFs) are emerging as a novel class of conductive redox‐active materials for electrochemical energy storage. However, developing 2D c‐MOFs as flexible thin‐film electrodes have been largely limited, due to the lack of capability of solution‐processing and integration into nanodevices arising from the rigid powder samples by solvothermal synthesis. Here, the synthesis of phthalocyanine‐based 2D c‐MOF (Ni2[CuPc(NH)8]) nanosheets through ball milling mechanical exfoliation method are reported. The nanosheets feature with average lateral size of ≈160 nm and mean thickness of ≈7 nm (≈10 layers), and exhibit high crystallinity and chemical stability as well as a p‐type semiconducting behavior with mobility of ≈1.5 cm2 V?1 s?1 at room temperature. Benefiting from the ultrathin feature, the nanosheets allow high utilization of active sites and facile solution‐processability. Thus, micro‐supercapacitor (MSC) devices are fabricated mixing Ni2[CuPc(NH)8] nanosheets with exfoliated graphene, which display outstanding cycling stability and a high areal capacitance up to 18.9 mF cm?2; the performance surpasses most of the reported conducting polymers‐based and 2D materials‐based MSCs. 相似文献
3.
Chuanfang Zhang Matthias P. Kremer Andrés Seral‐Ascaso Sang‐Hoon Park Niall McEvoy Babak Anasori Yury Gogotsi Valeria Nicolosi 《Advanced functional materials》2018,28(9)
The fast growth of portable smart electronics and internet of things have greatly stimulated the demand for miniaturized energy storage devices. Micro‐supercapacitors (MSCs), which can provide high power density and a long lifetime, are ideal stand‐alone power sources for smart microelectronics. However, relatively few MSCs exhibit both high areal and volumetric capacitance. Here rapid production of flexible MSCs is demonstrated through a scalable, low‐cost stamping strategy. Combining 3D‐printed stamps with arbitrary shapes and 2D titanium carbide or carbonitride inks (Ti3C2Tx and Ti3CNTx, respectively, known as MXenes), flexible all‐MXene MSCs with controlled architectures are produced. The interdigitated Ti3C2Tx MSC exhibits high areal capacitance: 61 mF cm?2 at 25 µA cm?2 and 50 mF cm?2 as the current density increases by 32 fold. The Ti3C2Tx MSCs also showcase capacitive charge storage properties, good cycling lifetime, high energy and power densities, etc. The production of such high‐performance Ti3C2Tx MSCs can be easily scaled up by designing pad or cylindrical stamps, followed by a cold rolling process. Collectively, the rapid, efficient production of flexible all‐MXene MSCs with state‐of‐the‐art performance opens new exciting opportunities for future applications in wearable and portable electronics. 相似文献
4.
Runsheng Gao Jie Tang Xiaoliang Yu Shiqi Lin Kun Zhang Lu‐Chang Qin 《Advanced functional materials》2020,30(27)
Silicon‐based materials have shown great potential and been widely studied in various fields. Unlike its unparalleled theoretical capacity as anodes for batteries, few investigations have been reported on silicon‐based materials for applications in supercapacitors. Here, an electrode composed of layered silicon‐based nanosheets, obtained through oxidation and exfoliation, for a supercapacitor operated up to 4 V is reported. These silicon‐based nanosheets show an areal specific capacitance of 4.43 mF cm?2 at 10 mV s?1 while still retaining a specific capacitance of 834 µF cm?2 even at an ultrahigh scan rate of 50 000 mV s?1. The volumetric energy and power density of the supercapacitor are 7.65 mWh cm?3 and 9312 mW cm?3, respectively, and the electrode can operate for 12000 cycles in a potential window of 4 V at 2 A g?1, while retaining 90.6% capacitance. These results indicate that the silicon‐based nanosheets can be a competitive candidate as the supercapacitor electrode material. 相似文献
5.
A flexible solid‐state asymmetric supercapacitor based on bendable film electrodes with 3D expressway‐like architecture of graphenes and “hard nano‐spacer” is fabricated via an extended filtration assisted method. In the designed structure of the positive electrode, graphene sheets are densely packed, and Ni(OH)2 nanoplates are intercalated in between the densely stacked graphenes. The 3D expressway‐like electrodes exhibit superior supercapacitive performance including high gravimetric capacitance (≈573 F g‐1), high volumetric capacitance (≈655 F cm‐3), excellent rate capability, and superior cycling stability. In addition, another hybrid film of graphene and carbon nanotubes (CNT) is fabricated as the negative electrodes for the designed asymmetric device. In the obtained graphene@CNT films, CNTs served as the hard spacer to prevent restacking of graphene sheets but also as a conductive and robust network to facilitate the electrons collection/transport in order to fulfill the demand of high‐rate performance of the asymmetric supercapacitor. Based on these two hybrid electrode films, a solid‐state flexible asymmetric supercapacitor device is assembled, which is able to deliver competitive volumetric capacitance of 58.5 F cm‐3 and good rate capacity. There is no obvious degradation of the supercapacitor performance when the device is in bending configuration, suggesting the excellent flexibility of the device. 相似文献
6.
Carbon‐Stabilized High‐Capacity Ferroferric Oxide Nanorod Array for Flexible Solid‐State Alkaline Battery–Supercapacitor Hybrid Device with High Environmental Suitability
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Ruizhi Li Yimeng Wang Cheng Zhou Chong Wang Xin Ba Yuanyuan Li Xintang Huang Jinping Liu 《Advanced functional materials》2015,25(33):5384-5394
Iron oxides are promising to be utilized in rechargeable alkaline battery with high capacity upon complete redox reaction (Fe3+ Fe0). However, their practical application has been hampered by the poor structural stability during cycling, presenting a challenge that is particularly huge when binder‐free electrode is employed. This paper proposes a “carbon shell‐protection” solution and reports on a ferroferric oxide–carbon (Fe3O4–C) binder‐free nanorod array anode exhibiting much improved cyclic stability (from only hundreds of times to >5000 times), excellent rate performance, and a high capacity of ≈7776.36 C cm?3 (≈0.4278 C cm?2; 247.5 mAh g?1, 71.4% of the theoretical value) in alkaline electrolyte. Furthermore, by pairing with a capacitive carbon nanotubes (CNTs) film cathode, a unique flexible solid‐state rechargeable alkaline battery‐supercapacitor hybrid device (≈360 μm thickness) is assembled. It delivers high energy and power densities (1.56 mWh cm?3; 0.48 W cm?3/≈4.8 s charging), surpassing many recently reported flexible supercapacitors. The highest energy density value even approaches that of Li thin‐film batteries and is about several times that of the commercial 5.5 V/100 mF supercapacitor. In particular, the hybrid device still maintains good electrochemical attributes in cases of substantially bending, high mechanical pressure, and elevated temperature (up to 80 °C), demonstrating high environmental suitability. 相似文献
7.
Micro‐supercapacitors (MSCs), albeit powerful, are unable to broaden their potential applications primarily because they are not as flexible and morphable as electronics. To address this problem, a universal strategy to fabricate substrate‐free, ultrathin, shapeless planar‐MSCs with high‐performance tenability under serious deformation is put forward. These represent a new class of “all‐inside‐one” film supercapacitors, achieved by encapsulating two‐dimensional interdigital microelectrodes within chemically cross‐linked polyvinyl‐alcohol‐based hydrogel electrolyte containing graphene oxide (GO). GO nanosheets significantly improve ionic conductivity, enhance the capacitance, and boost robustness of hydrogel electrolyte. Consequently, the entire MSC, while being only 37 µm thick, can be crumpled and its shape can self‐adjust through fluid channel ten times smaller than its original size without any damage, demonstrating shapelessness. Using MXene as active material, high single‐cell areal capacitance of 40.8 mF cm?2 is achieved from microelectrodes as thin as 5 µm. Furthermore, to demonstrate wide applicability of this protocol, screen‐printed graphene‐based highly integrated MSCs connecting nine cells in series are fabricated to stably output a high voltage of 7.2 V while crumpling them from 0.11 to 0.01 cm?3, manifesting superior performance uniformity. This protocol allows the coexistence of high performance with incredible flexibility that may greatly diversify MSCs' applications. 相似文献
8.
Flexible Cellulose Paper‐based Asymmetrical Thin Film Supercapacitors with High‐Performance for Electrochemical Energy Storage
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Jin‐Xian Feng Sheng‐Hua Ye An‐Liang Wang Xue‐Feng Lu Ye‐Xiang Tong Gao‐Ren Li 《Advanced functional materials》2014,24(45):7093-7101
Cellulose paper (CP)‐based asymmetrical thin film supercapacitors (ATFSCs) have been considered to be a novel platform for inexpensive and portable devices as the CP is low‐cost, lightweight, and can be rolled or folded into 3D configurations. However, the low energy density and poor cycle stability are serious bottlenecks for the development of CP‐based ATFSCs. Here, sandwich‐structured graphite/Ni/Co2NiO4‐CP is developed as positive electrode and the graphite/Ni/AC‐CP as negative electrode for flexible and high‐performance ATFSCs. The fabricated graphite/Ni/Co2NiO4‐CP positive electrode shows a superior areal capacitance (734 mF/cm2 at 5 mV/s) and excellent cycling performance with ≈97.6% Csp retention after 15 000 cycles. The fabricated graphite/Ni/AC‐CP negative electrode also exhibits large areal capacitance (180 mF/cm2 at 5 mV/s) and excellent cycling performance with ≈98% Csp retention after 15 000 cycles. The assembled ATFSCs based on the sandwich‐structured graphite/Ni/Co2NiO4‐CP as positive electrode and graphite/Ni/AC‐CP as negative electrode exhibit large volumetric Csp (7.6 F/cm3 at 5 mV/s), high volumetric energy density (2.48 mWh/cm3, 80 Wh/kg), high volumetric power density (0.79 W/cm3, 25.6 kW/kg) and excellent cycle stability (less 4% Csp loss after 20 000 cycles). This study shows an important breakthrough in the design and fabrication of high‐performance and flexible CP‐based electrodes and ATFSCs. 相似文献
9.
Flexible All‐Solid‐State Supercapacitors of High Areal Capacitance Enabled by Porous Graphite Foams with Diverging Microtubes
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Weigu Li Marshall C. Tekell Chang Liu Jacob A. Hethcock Donglei Fan 《Advanced functional materials》2018,28(29)
The practical applications of wearable electronics rely on the successful development of flexible and integrable energy devices with small footprints. This work reports a completely new type of graphite foam made of strategically created superstructures with covalently attached diverging microtubes, and their applications as electrode supports for binder‐free and additive‐free flexible supercapacitors. Because of the enhanced volumetric surface areas compared to conventional graphite foams, a high loading of pseudocapacitive materials (Mn3O4, 3.91 mg cm?2, 78 wt%) is achieved. The supercapacitors provide areal capacitances as high as 820 mF cm?2 at 1 mV s?1, while still maintaining high rate capability and 88% retention of capacitance after 3000 continuous charging and discharging cycles. When assembled as all‐solid‐state flexible symmetric supercapacitors, they offer one of the highest full‐cell capacitances (191 mF cm?2) among similar manganese oxide/graphene foams, and retain 80% capacitance after 1000 mechanical cycles. The potential of such flexible supercapacitors is also manifested by directly powering electric nanomotors that can trace along letters “U” and T,” which is the first demonstration of flexible supercapacitors for wireless/portable nanomanipulation systems. This work could inspire a new paradigm in designing and creating 3D porous micro/nanosuperstructures for an array of self‐powered electronic and nanomechanical applications. 相似文献
10.
Manikandan Ramu Justin Raj Chellan Nagaraju Goli Puigdollers Joaquim Voz Cristobal Byung Chul Kim 《Advanced functional materials》2020,30(6)
The developments of rationally designed binder‐free metal chalcogenides decorated flexible electrodes are of paramount importance for advanced energy storage devices. Herein, binder‐free patronite (VS4) flower‐like nanostructures are facilely fabricated on a carbon cloth (CC) using a facile hydrothermal method for high‐performance supercapacitors. The growth density and morphology of VS4 nanostructures on CC are also controlled by varying the concentrations of vanadium and sulfur sources along with the complexing agent in the growth solution. The optimal electrode with an appropriate growth concentration (VS4‐CC@VS‐3) demonstrates a considerable pseudocapacitance performance in the ionic liquid (IL) electrolyte (1‐ethyl‐3‐methylimidazolium trifluoromethanesulfonate), with a high operating potential of 2 V. Utilizing VS4‐CC@VS‐3 as both positive and negative electrodes, the IL‐based symmetric supercapacitor is assembled, which demonstrates a high areal capacitance of 536 mF cm?2 (206 F g?1) and excellent cycling durability (93%) with superior energy and power densities of 74.4 µWh cm?2 (28.6 Wh kg?1) and 10154 µW cm?2 (9340 W kg?1), respectively. As for the high energy storage performance, the device stably energizes various portable electronic applications for a long time, which make the fabricated composite material open up news for the fabrication of fabrics supported binder‐free chalcogenides for high‐performance energy storage devices. 相似文献
11.
Development of Graphene Oxide/Polyaniline Inks for High Performance Flexible Microsupercapacitors via Extrusion Printing
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Yuqing Liu Binbin Zhang Qun Xu Yuyang Hou Shayan Seyedin Si Qin Gordon G. Wallace Stephen Beirne Joselito M. Razal Jun Chen 《Advanced functional materials》2018,28(21)
Extrusion printing of interdigitated electrodes for flexible microsupercapacitors (fMSCs) offers an attractive route to the fabrication of flexible devices where cost, scalability, and processability of ink formulations are critical. In this work, highly concentrated, viscous, and water‐dispersible inks are developed based on graphene oxide (GO)/polyaniline (PANi) composite for extrusion printing. The optimized GO/PANi‐based all‐solid‐state symmetric fMSCs obtained by extrusion printing interdigitated microelectrodes can deliver outstanding areal capacitance of 153.6 mF cm?2 and volumetric capacitance of 19.2 F cm?3 at 5 mV s?1. It is shown that by fabricating asymmetric fMSCs using the GO/PANi as positive electrode and a graphene‐based negative electrode, the voltage window can be widened from 0.8 to 1.2 V and improvements can be achieved in energy density (from 3.36 to 4.83 mWh cm?3), power density (from 9.82 to 25.3 W cm?3), and cycling stability (from 75% to 100% capacitance retention over 5000 cycles) compared with the symmetric counterpart. The simple ink preparation and facile device fabrication protocols reported here make the scalable fabrication of extrusion printed fMSCs a promising technology. 相似文献
12.
Flexible and Wire‐Shaped Micro‐Supercapacitor Based on Ni(OH)2‐Nanowire and Ordered Mesoporous Carbon Electrodes
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Xiaoli Dong Ziyang Guo Yanfang Song Mengyan Hou Jianqiang Wang Yonggang Wang Yongyao Xia 《Advanced functional materials》2014,24(22):3405-3412
Portable and multifunctional electronic devices are developing in the trend of being small, flexible, roll‐up, and even wearable, which asks us to develop flexible and micro‐sized energy conversion/storage devices. Here, the high performance of a flexible, wire‐shaped, and solid‐state micro‐supercapacitor, which is prepared by twisting a Ni(OH)2‐nanowire fiber‐electrode and an ordered mesoporous carbon fiber‐electrode together with a polymer electrolyte, is demonstrated. This micro‐supercapacitor displays a high specific capacitance of 6.67 mF cm–1 (or 35.67 mF cm–2) and a high specific energy density of 0.01 mWh cm–2 (or 2.16 mWh cm–3), which are about 10–100 times higher than previous reports. Furthermore, its capacitance retention is 70% over 10 000 cycles, indicating perfect cyclic ability. Two wire‐shaped micro‐supercapacitors (0.6 mm in diameter, ≈3 cm in length) in series can successfully operate a red light‐emitting‐diode, indicating promising practical application. Furthermore, synchrotron radiation X‐ray computed microtomography technology is employed to investigate inner structure of the micro‐device, confirming its solid‐state characteristic. This micro‐supercapacitor may bring new design opportunities of device configuration for energy‐storage devices in the future wearable electronic area. 相似文献
13.
Kaiyue Jiang Igor A. Baburin Peng Han Chongqing Yang Xiaobin Fu Yefeng Yao Jiantong Li Enrique Cnovas Gotthard Seifert Jiesheng Chen Mischa Bonn Xinliang Feng Xiaodong Zhuang 《Advanced functional materials》2020,30(7)
2D soft nanomaterials are an emerging research field due to their versatile chemical structures, easily tunable properties, and broad application potential. In this study, a benzene‐bridged polypyrrole film with a large area, up to a few square centimeters, is synthesized through an interfacial polymerization approach. As‐prepared semiconductive films exhibit a bandgap of ≈2 eV and a carrier mobility of ≈1.5 cm2 V?1 s?1, inferred from time‐resolved terahertz spectroscopy. The samples are employed to fabricate in‐plane micro‐supercapacitors (MSCs) by laser scribing and exhibit an ultrahigh areal capacitance of 0.95 mF cm?2, using 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([EMIM][BF4]) as an electrolyte. Importantly, the maximum energy and power densities of the developed MSCs reach values up to 50.7 mWh cm?3 and 9.6 kW cm?3, respectively; the performance surpassing most of the 2D material‐based MSCs is reported to date. 相似文献
14.
Oxygen‐Deficient Bismuth Oxide/Graphene of Ultrahigh Capacitance as Advanced Flexible Anode for Asymmetric Supercapacitors
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Rong Liu Lina Ma Gudan Niu Xiaolong Li Enyuan Li Yang Bai Guohui Yuan 《Advanced functional materials》2017,27(29)
Oxygen‐deficient bismuth oxide (r‐Bi2O3)/graphene (GN) is designed, fabricated, and demonstrated via a facile solvothermal and subsequent solution reduction method. The ultrafine network bacterial cellulose (BC) as substrate for r‐Bi2O3/GN exhibits high flexibility, remarkable tensile strength (55.1 MPa), and large mass loading of 9.8 mg cm?2. The flexible r‐Bi2O3/GN/BC anode delivers appreciable areal capacitance (6675 mF cm?2 at 1 mA cm?2) coupled with good rate capability (3750 mF cm?2 at 50 mA cm?2). In addition, oxygen vacancies have great influence on the capacitive performance of Bi2O3, delivering significantly improved capacitive values than the untreated Bi2O3 flexible electrode, and ultrahigh gravimetric capacitance of 1137 F g?1 (based on the mass of r‐Bi2O3) can be obtained, achieving 83% of the theoretical value (1370 F g?1). Flexible asymmetric supercapacitor is fabricated with r‐Bi2O3/GN/BC and Co3O4/GN/BC paper as the negative and positive electrodes, respectively. The operation voltage is expanded to 1.6 V, revealing a maximum areal energy density of 0.449 mWh cm?2 (7.74 mWh cm?3) and an areal power density of 40 mW cm?2 (690 mW cm?3). Therefore, this flexible anode with excellent electrochemical performance and high mechanical properties shows great potential in the field of flexible energy storage devices. 相似文献
15.
High‐Performance Wearable Micro‐Supercapacitors Based on Microfluidic‐Directed Nitrogen‐Doped Graphene Fiber Electrodes
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Guan Wu Pengfeng Tan Xingjiang Wu Lu Peng Hengyang Cheng Cai‐Feng Wang Wei Chen Ziyi Yu Su Chen 《Advanced functional materials》2017,27(36)
Fiber‐shaped micro‐supercapacitors (micro‐SCs) have attracted enormous interest in wearable electronics due to high flexibility and weavability. However, they usually present a low energy density because of inhomogeneity and less pores. Here, we demonstrate a microfluidic‐directed strategy to synthesize homogeneous nitrogen‐doped porous graphene fibers. The porous fibers‐based micro‐SCs utilize solid‐state phosphoric acid/polyvinyl alcohol (H3PO4/PVA) and 1‐ethyl‐3‐methylimidazolium tetrafluoroborate/poly(vinylidenefluoride‐co‐hexafluoropropylene) (EMIBF4/PVDF‐HFP) electrolytes, which show significant improvements in electrochemical performances. Ultralarge capacitance (1132 mF cm?2), high cycling‐stability, and long‐term bending‐durability are achieved based on H3PO4/PVA. Additionally, high energy densities of 95.7–46.9 µWh cm?2 at power densities of 1.5–15 W cm?2 are obtained in EMIBF4/PVDF‐HFP. The key to higher performances stems from microfluidic‐controlled fibers with a uniformly porous network, large specific surface area (388.6 m2 g?1), optimal pyridinic nitrogen (2.44%), and high electric conductivity (30785 S m?1) for faster ion diffusion and flooding accommodation. By taking advantage of these remarkable merits, this study integrates micro‐SCs into flexible and fabric substrates to power audio–visual electronics. The main aim is to clarify the important role of microfluidic techniques toward the architecture of electrodes and promote development of wearable electronics. 相似文献
16.
A novel method for fabricating micro‐patterned interdigitated electrodes based on reduced graphene oxide (rGO) and carbon nanotube (CNT) composites for ultra‐high power handling micro‐supercapacitor application is reported. The binder‐free microelectrodes were developed by combining electrostatic spray deposition (ESD) and photolithography lift‐off methods. Without typically used thermal or chemical reduction, GO sheets are readily reduced to rGO during the ESD deposition. Electrochemical measurements show that the in‐plane interdigital design of the microelectrodes is effective in increasing accessibility of electrolyte ions in‐between stacked rGO sheets through an electro‐activation process. Addition of CNTs results in reduced restacking of rGO sheets and improved energy and power density. Cyclic voltammetry (CV) measurements show that the specific capacitance of the micro‐supercapacitor based on rGO–CNT composites is 6.1 mF cm?2 at 0.01 V s?1. At a very high scan rate of 50 V s?1, a specific capacitance of 2.8 mF cm?2 (stack capacitance of 3.1 F cm?3) is recorded, which is an unprecedented performance for supercapacitors. The addition of CNT, electrolyte‐accessible and binder‐free microelectrodes, as well as an interdigitated in‐plane design result in a high‐frequency response of the micro‐supercapacitors with resistive‐capacitive time constants as low as 4.8 ms. These characteristics suggest that interdigitated rGO–CNT composite electrodes are promising for on‐chip energy storage application with high power demands. 相似文献
17.
A Low‐Cost,Self‐Standing NiCo2O4@CNT/CNT Multilayer Electrode for Flexible Asymmetric Solid‐State Supercapacitors
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Peng Wu Shuang Cheng Minghai Yao Lufeng Yang Yuanyuan Zhu Peipei Liu Ou Xing Jun Zhou Mengkun Wang Haowei Luo Meilin Liu 《Advanced functional materials》2017,27(34)
The demand for a new generation of flexible, portable, and high‐capacity power sources increases rapidly with the development of advanced wearable electronic devices. Here we report a simple process for large‐scale fabrication of self‐standing composite film electrodes composed of NiCo2O4@carbon nanotube (CNT) for supercapacitors. Among all composite electrodes prepared, the one fired in air displays the best electrochemical behavior, achieving a specific capacitance of 1,590 F g?1 at 0.5 A g?1 while maintaining excellent stability. The NiCo2O4@CNT/CNT film electrodes are fabricated via stacking NiCo2O4@CNT and CNT alternately through vacuum filtration. Lightweight, flexible, and self‐standing film electrodes (≈24.3 µm thick) exhibit high volumetric capacitance of 873 F cm?3 (with an areal mass of 2.5 mg cm?2) at 0.5 A g?1. An all‐solid‐state asymmetric supercapacitor consists of a composite film electrode and a treated carbon cloth electrode has not only high energy density (≈27.6 Wh kg?1) at 0.55 kW kg?1 (including the weight of the two electrodes) but also excellent cycling stability (retaining ≈95% of the initial capacitance after 5000 cycles), demonstrating the potential for practical application in wearable devices. 相似文献
18.
Flexible Ti3C2Tx@Al electrodes with Ultrahigh Areal Capacitance: In Situ Regulation of Interlayer Conductivity and Spacing
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Miao Guo Chengbin Liu Zezhong Zhang Jian Zhou Yanhong Tang Shenglian Luo 《Advanced functional materials》2018,28(37)
Although Ti3C2 MXene has shown great potential in energy storage field, poor conductivity and restacking between MXene flakes seriously hinders the maximization of its capacitance. Herein, a new strategy to solve the problems is developed. Gallery Al atoms in Ti3AlC2 are partially removed by simple hydrothermal etching to get Ti3C2Tx reserving appropriate Al interlayers (Ti3C2Tx@Al). Ti3C2Tx@Al keeps stable layered structure rather than isolated Ti3C2Tx flakes, which avoids flake restacking. The removal of partial Al frees up space for easy electrolyte infiltration while the reserved Al as “electron bridges” ensures high interlayer conductivity. As a result, the areal capacitance reaches up to 1087 mF cm?2 at 1 mA cm?2 and over 95% capacitance is maintained after 6000 cycles. The all‐solid‐state supercapacitor (ASSS) based on Ti3C2Tx@Al delivers a high capacitance of 242.3 mF cm?2 at 1 mV s?1 and exhibits stable performance at different bending states. Two ASSSs in tandem can light up a light‐emitting diode under the planar or wrapping around an arm. The established strategy provides a new avenue to improve capacitance performances of MXenes. 相似文献
19.
Flexible Solid‐State Supercapacitors with Enhanced Performance from Hierarchically Graphene Nanocomposite Electrodes and Ionic Liquid Incorporated Gel Polymer Electrolyte
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Lanxiang Feng Kai Wang Xiong Zhang Xianzhong Sun Chen Li Xingbo Ge Yanwei Ma 《Advanced functional materials》2018,28(4)
High energy density, durability, and flexibility of supercapacitors are required urgently for the next generation of wearable and portable electronic devices. Herein, a novel strategy is introduced to boost the energy density of flexible soild‐state supercapacitors via rational design of hierarchically graphene nanocomposite (GNC) electrode material and employing an ionic liquid gel polymer electrolyte. The hierarchical graphene nanocomposite consisting of graphene and polyaniline‐derived carbon is synthesized as an electrode material via a scalable process. The meso/microporous graphene nanocomposites exhibit a high specific capacitance of 176 F g?1 at 0.5 A g?1 in the ionic liquid 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIBF4) with a wide voltage window of 3.5 V, good rate capability of 80.7% in the range of 0.5–10 A g?1 and excellent stability over 10 000 cycles, which is attributed to the superior conductivity (7246 S m?1), and quite large specific surface area (2416 m2 g?1) as well as hierarchical meso/micropores distribution of the electrode materials. Furthermore, flexible solid‐state supercapacitor devices based on the GNC electrodes and gel polymer electrolyte film are assembled, which offer high specific capacitance of 180 F g?1 at 1 A g?1, large energy density of 75 Wh Kg?1, and remarkable flexible performance under consecutive bending conditions. 相似文献
20.
Sputtered Titanium Carbide Thick Film for High Areal Energy on Chip Carbon‐Based Micro‐Supercapacitors
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Manon Létiche Kevin Brousse Arnaud Demortière Peihua Huang Barbara Daffos Sébastien Pinaud Marc Respaud Bruno Chaudret Pascal Roussel Lionel Buchaillot Pierre Louis Taberna Patrice Simon Christophe Lethien 《Advanced functional materials》2017,27(20)
The areal energy density of on‐chip micro‐supercapacitors should be improved in order to obtain autonomous smart miniaturized sensors. To reach this goal, high surface capacitance electrode (>100 mF cm?2) has to be produced while keeping low the footprint area. For carbide‐derived carbon (CDC) micro‐supercapacitors, the properties of the metal carbide precursor have to be fine‐tuned to fabricate thick electrodes. The ad‐atoms diffusion process and atomic peening effect occurring during the titanium carbide sputtering process are shown to be the key parameters to produce low stress, highly conductive, and thick TiC films. The sputtered TiC at 10?3 mbar exhibits a high stress level, limiting the thickness of the TiC‐CDC electrode to 1.5 µm with an areal capacitance that is less than 55 mF cm?2 in aqueous electrolyte. The pressure increase up to 10?2 mbar induces a clear reduction of the stress level while the layer thickness increases without any degradation of the TiC electronic conductivity. The volumetric capacitance of the TiC‐CDC electrodes is equal to 350 F cm?3 regardless of the level of pressure. High values of areal capacitance (>100 mF cm?2) are achieved, whereas the TiC layer is relatively thick, which paves the way toward high‐performance micro‐supercapacitors. 相似文献