共查询到20条相似文献,搜索用时 31 毫秒
1.
Sebastiano Bellani Elisa Petroni Antonio Esau Del Rio Castillo Nicola Curreli Beatriz Martín‐García Reinier Oropesa‐Nuez Mirko Prato Francesco Bonaccorso 《Advanced functional materials》2019,29(14)
The miniaturization of energy storage units is pivotal for the development of next‐generation portable electronic devices. Micro‐supercapacitors (MSCs) hold great potential to work as on‐chip micro‐power sources and energy storage units complementing batteries and energy harvester systems. Scalable production of supercapacitor materials with cost‐effective and high‐throughput processing methods is crucial for the widespread application of MSCs. Here, wet‐jet milling exfoliation of graphite is reported to scale up the production of graphene as a supercapacitor material. The formulation of aqueous/alcohol‐based graphene inks allows metal‐free, flexible MSCs to be screen‐printed. These MSCs exhibit areal capacitance (Careal) values up to 1.324 mF cm?2 (5.296 mF cm?2 for a single electrode), corresponding to an outstanding volumetric capacitance (Cvol) of 0.490 F cm?3 (1.961 F cm?3 for a single electrode). The screen‐printed MSCs can operate up to a power density above 20 mW cm?2 at an energy density of 0.064 µWh cm?2. The devices exhibit excellent cycling stability over charge–discharge cycling (10 000 cycles), bending cycling (100 cycles at a bending radius of 1 cm) and folding (up to angles of 180°). Moreover, ethylene vinyl acetate‐encapsulated MSCs retain their electrochemical properties after a home‐laundry cycle, providing waterproof and washable properties for prospective application in wearable electronics. 相似文献
2.
Multilayer‐Folded Graphene Ribbon Film with Ultrahigh Areal Capacitance and High Rate Performance for Compressible Supercapacitors 下载免费PDF全文
Lizhi Sheng Jin Chang Lili Jiang Zimu Jiang Zheng Liu Tong Wei Zhuangjun Fan 《Advanced functional materials》2018,28(21)
Limited by 2D geometric morphology and low bulk packing density, developing graphene‐based flexible/compressible supercapacitors with high specific capacitances (gravimetric/volumetric/areal), especially at high rates, is an outstanding challenge. Here, a strategy for the synthesis of free‐standing graphene ribbon films (GRFs) for high‐performance flexible and compressible supercapacitors through blade‐coating of interconnected graphene oxide ribbons and a subsequent thermal treatment process is reported. With an ultrahigh mass loading of 21 mg cm?2, large ion‐accessible surface area, efficient electron and ion transport pathways as well as high packing density, the compressed multilayer‐folded GRF films (F‐GRF) exhibit ultrahigh areal capacitance of 6.7 F cm?2 at 5 mA cm?2, high gravimetric/volumetric capacitances (318 F g?1, 293 F cm?3), and high rate performance (3.9 F cm?2 at 105 mA cm?2), as well as excellent cycling stability (109% of capacitance retention after 40 000 cycles). Furthermore, the assembled F‐GRF symmetric supercapacitor with compressible and flexible characteristics, can deliver an ultrahigh areal energy density of 0.52 mWh cm?2 in aqueous electrolyte, almost two times higher than the values obtained from symmetric supercapacitors with comparable dimensions. 相似文献
3.
Flexible Cellulose Paper‐based Asymmetrical Thin Film Supercapacitors with High‐Performance for Electrochemical Energy Storage 下载免费PDF全文
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
4.
Hierarchical Ni–Co Hydroxide Petals on Mechanically Robust Graphene Petal Foam for High‐Energy Asymmetric Supercapacitors 下载免费PDF全文
Guoping Xiong Pingge He Dini Wang Qiangqiang Zhang Tengfei Chen Timothy S. Fisher 《Advanced functional materials》2016,26(30):5460-5470
A hierarchical structure consisting of Ni–Co hydroxide nanopetals (NCHPs) grown on a thin free‐standing graphene petal foam (GPF) has been designed and fabricated by a two‐step process for pseudocapacitive electrode applications. The mechanical behavior of GPFs has been, for the first time to our knowledge, quantitatively measured from in situ scanning electron microscope characterization of the petal foams during in‐plane compression and bending processes. The Young's modulus of a typical GPF is 3.42 GPa, indicating its outstanding mechanical robustness as a nanotemplate. The GPF/NCHP electrodes exhibit volumetric capacitances as high as 765 F cm?3, equivalent to an areal capacitance of 15.3 F cm?2 and high rate capability. To assess practical functionality, two‐terminal asymmetric solid‐state supercapacitors with 3D GPF/NCHPs as positive electrodes are fabricated and shown to exhibit outstanding energy and power densities, with maximum average energy density of ≈10 mWh cm?3 and maximum power density of ≈3 W cm?3, high rate capability (a capacitance retention of ≈60% at 100 mA cm?2), and excellent long‐term cyclic stability (full capacitance retention over 15 000 cycles). 相似文献
5.
Ultralight and Binder‐Free All‐Solid‐State Flexible Supercapacitors for Powering Wearable Strain Sensors 下载免费PDF全文
Weigu Li Chang Liu Marshall C. Tekell Jing Ning Jianhe Guo Jincheng Zhang Donglei Fan 《Advanced functional materials》2017,27(39)
Flexible energy storage devices play a pivotal role in realizing the full potential of flexible electronics. This work presents high‐performance, all‐solid‐state, flexible supercapacitors by employing an innovative multilevel porous graphite foam (MPG). MPGs exhibit superior properties, such as large specific surface area, high electric conductivity, low mass density, high loading efficiency of pseudocapacitive materials, and controlled corrugations for accommodating mechanical strains. When loaded with pseudocapacitive manganese oxide (Mn3O4), the MPG/Mn3O4 (MPGM) composites achieve a specific capacitance of 538 F g?1 (1 mV s?1) and 260 F g?1 (1 mV s?1) based on the mass of pure Mn3O4 and entire electrode composite, respectively. Both are among the best of Mn3O4‐based supercapacitors. The MPGM is mechanically robust and can go through 1000 mechanical bending cycles with only 1.5% change in electric resistance. When integrated as all‐solid‐state symmetric supercapacitors, they offer a full cell specific capacitance as high as 53 F g?1 based on the entire electrode and retain 80% of capacitance after 1000 continuous mechanical bending cycles. Furthermore, the all‐solid‐state flexible supercapacitors are incorporated with strain sensors into self‐powered flexible devices for detection of both coarse and fine motions on human skins, i.e., those from finger bending and heart beating. 相似文献
6.
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
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.
Sputtered Titanium Carbide Thick Film for High Areal Energy on Chip Carbon‐Based Micro‐Supercapacitors 下载免费PDF全文
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
9.
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
10.
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
11.
Carbon‐Stabilized High‐Capacity Ferroferric Oxide Nanorod Array for Flexible Solid‐State Alkaline Battery–Supercapacitor Hybrid Device with High Environmental Suitability 下载免费PDF全文
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
12.
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
13.
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
14.
Flexible and Wire‐Shaped Micro‐Supercapacitor Based on Ni(OH)2‐Nanowire and Ordered Mesoporous Carbon Electrodes 下载免费PDF全文
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
15.
Yue Dong Su Zhang Xian Du Song Hong Shengna Zhao Yaxin Chen Xiaohong Chen Huaihe Song 《Advanced functional materials》2019,29(24)
Improving the capacitance of carbon materials for supercapacitors without sacrificing their rate performance, especially volumetric capacitance at high mass loadings, is a big challenge because of the limited assessable surface area and sluggish electrochemical kinetics of the pseudocapacitive reactions. Here, it is demonstrated that “self‐doping” defects in carbon materials can contribute to additional capacitance with an electrical double‐layer behavior, thus promoting a significant increase in the specific capacitance. As an exemplification, a novel defect‐enriched graphene block with a low specific surface area of 29.7 m2 g?1 and high packing density of 0.917 g cm?3 performs high gravimetric, volumetric, and areal capacitances of 235 F g?1, 215 F cm?3, and 3.95 F cm?2 (mass loading of 22 mg cm?2) at 1 A g?1, respectively, as well as outstanding rate performance. The resulting specific areal capacitance reaches an ultrahigh value of 7.91 F m?2 including a “self‐doping” defect contribution of 4.81 F m?2, which is dramatically higher than the theoretical capacitance of graphene (0.21 F m?2) and most of the reported carbon‐based materials. Therefore, the defect engineering route broadens the avenue to further improve the capacitive performance of carbon materials, especially for compact energy storage under limited surface areas. 相似文献
16.
Flexible Asymmetric Supercapacitor Based on Structure‐Optimized Mn3O4/Reduced Graphene Oxide Nanohybrid Paper with High Energy and Power Density 下载免费PDF全文
Yating Hu Cao Guan Guangxue Feng Qingqing Ke Xiaolei Huang John Wang 《Advanced functional materials》2015,25(47):7291-7299
A highly flexible Mn3O4/reduced graphene oxide (rGO) nanohybrid paper with high electrical conductivity and high mass loading of Mn3O4 nanofibers (0.71 g cm?3) is developed via a facile gel formation and electrochemical reduction process, which is low‐cost, environmental friendly, and easy to scale up. Confined Mn3O4 nanofibers are well dispersed within the rGO sheets, which demonstrate to be a promising cathode material for flexible asymmetric supercapacitors (ASCs). When coupled with an electrochemically reduced rGO paper as the anode, a flexible ASC device, based on the Mn3O4/rGO nanohybrid paper as the cathode, is assembled; and it demonstrates remarkable electrochemical performance: a high volumetric capacitance of 54.6 F cm?3 (546.05 mF cm?2), and remarkable volumetric energy and power density (0.0055 Wh cm?3 and 10.95 W cm?3) being achieved with excellent cycling ability. The nanohybrid paper shows great improvement for flexible energy devices in terms of electrochemical properties. 相似文献
17.
High‐Performance Wearable Micro‐Supercapacitors Based on Microfluidic‐Directed Nitrogen‐Doped Graphene Fiber Electrodes 下载免费PDF全文
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
18.
A Low‐Cost,Self‐Standing NiCo2O4@CNT/CNT Multilayer Electrode for Flexible Asymmetric Solid‐State Supercapacitors 下载免费PDF全文
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
19.
Denisa Hulicova‐Jurcakova Masaya Kodama Soshi Shiraishi Hiroaki Hatori Zong Hua Zhu Gao Qing Lu 《Advanced functional materials》2009,19(11):1800-1809
Nitrogen‐enriched nonporous carbon materials derived from melamine–mica composites are subjected to ammonia treatment to further increase the nitrogen content. For samples preoxidized prior to the ammonia treatment, the nitrogen content is doubled and is mainly incorporated in pyrrol‐like groups. The materials are tested as electrodes for supercapacitors, and in acidic or basic electrolytes, the gravimetric capacitance of treated samples is three times higher than that of untreated samples. This represents a tenfold increase of the capacitance per surface area (3300 µF cm?2) in basic electrolyte. Due to the small volume of the carbon materials, high volumetric capacitances are achieved in various electrolytic systems: 280 F cm?3 in KOH, 152 F cm?3 in H2SO4, and 92 F cm?3 in tetraethylammonium tetrafluoroborate/propylene carbonate. 相似文献
20.
Peng Chang Hui Mei Yu Zhao Weizhao Huang Shixiang Zhou Laifei Cheng 《Advanced functional materials》2019,29(34)
Developing advanced three‐dimensional (3D) structural supercapacitors with both high capacity and good mechanical strength remains challenging. Herein, a novel road is reported for fabricating 3D structural strengthening supercapacitors with adjustable capacitance based on urchin‐like Cu(OH)2 lattice electrodes by bridging 3D printing technology with a facile electroless plating and electro‐oxidation method. As revealed by the results, the 3D‐printed octet‐truss lattice electrode features a high volumetric capacitance of 8.46 F cm?3 at 5 mA cm?3 and superior retention capacity of 68% at 1 A cm?3. The assembled symmetric supercapacitor with a 70.2% capacitance retention after 5000 cycles possesses a 12.8 Wh kg?1 energy density at a power density of 2110.2 W kg?1. Additionally, the resulting 3D structural strengthening electrodes can achieve both high compressive strength and toughness of 30 MPa and 264.7 kJ m?3, respectively, demonstrating high mechanical strength and excellent antideformation capacity. With the proposed strategy, the electrochemical and mechanical properties of these novel 3D structural strengthened supercapacitors can be easily tuned by a simple spatial framework design, fulfilling the increasing demand of highly customized power sources in the space‐constrained microelectronics and astronautic electronics industries. 相似文献