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1.
Chemical architectures with an ordered porous backbone and high charge transfer are significant for fiber‐shaped supercapacitors (FSCs). However, owing to the sluggish ion kinetic diffusion and storage in compacted fibers, achieving high energy density remains a challenge. An innovative magnetothermal microfluidic method is now proposed to design hierarchical carbon polyhedrons/holey graphene (CP/HG) core–shell microfibers. Owing to highly magnetothermal etching and microfluidic reactions, the CP/HG fibers maintain an open inner‐linked ionic pathway, large specific surface area, and moderate nitrogen active site, facilitating more rapid ionic dynamic transportation and accommodation. The CP/HG FSCs show an ultrahigh energy density (335.8 μWh cm?2) and large areal capacitance (2760 mF cm?2). A self‐powered endurance application with the integration of chip‐based FSCs is designed to profoundly drive the durable motions of an electric car and walking robot.  相似文献   

2.
Fiber-shaped supercapacitors (FSCs) have become one of the significantly strategical flexible energy-storage materials towards future wearable textile electronics and metaverse technologies. Here, we develop the high-performance FSCs based on multiscale dot-wire-sheet heterostructure microfiber of nitrogen-doped carbon dots-Ti3C2Tx/silk nanofibers (NCDs-Ti3C2Tx/SNFs) hybrids via microfluidic fabrication. Due to the enlarged interlayer spacing, plentiful porous channels, accelerated H+ ion transport dynamics, large electrical conductivity and excellent mechanical strength/flexibility, the NCDs-Ti3C2Tx/SNFs possesses high volumetric capacitance (2218.7 F cm−3) and reversible charge–discharge stability in 1 M H2SO4 electrolyte. Furthermore, the solid-state FSCs present high energy density (57.9 mWh cm−3), good capacitance (1157 F cm−3), long-life cycles (82.3 % capacitance retention after 40000 cycles), which realize the actual energy-supply applications (powering lamp, watch and toy car).  相似文献   

3.
A 2D boron nanosheet that exhibits high theoretical capacitance, around four times that of graphene, is a significant supercapacitor electrode. However, its bulk structure with low interlaminar conduction and porosity restricts the charge transfer, ion diffusion, and energy density. Herein, we develop a new 2D hetero-nanosheet made of anisotropic boron–carbon nanosheets (ABCNs) by B−C chemical bonds via gas-phase exfoliation and condensation bottom-up strategy. The ABCNs are constructed into high flexible supercapacitor electrode by microfluidic electrospinning. The ABCN electrode greatly promotes smooth migration and excessive storage of electrolyte ions due to large interlayer conductivity, ionic pathways, and accessible surfaces. The flexible supercapacitor delivers ultrahigh volumetric energy density of 167.05 mWh cm−3 and capacitance of 534.5 F cm−3. A wearable energy-sensor system is designed to stably monitor physiological signals.  相似文献   

4.
Although graphene fiber-based supercapacitors are promising for wearable electronic devices, the low energy density of electrodes and poor cold resistance of aqueous electrolytes limit their wide application in cold environments. Herein, porous nitrogen/sulfur dual-doped graphene fibers (NS-GFs) are synthesized by hydrothermal self-assembly followed by thermal annealing, exhibiting an excellent capacitive performance of 401 F cm−3 at 400 mA cm−3 because of the synergistic effect of heteroatom dual-doping. The assembled symmetric all-solid-state supercapacitor with polyvinyl alcohol/H2SO4/graphene oxide gel electrolyte exhibits a high capacitance of 221 F cm−3 and a high energy density of 7.7 mWh cm−3 at 80 mA cm−3. Interestingly, solar–thermal energy conversion of the electrolyte with 0.1 wt % graphene oxide extends the operating temperature range of the supercapacitor to 0 °C. Furthermore, the photocatalysis effect of the dual-doped heteroatoms increases the capacitance of NS-GFs. At an ambient temperature of 0 °C, the capacitance increases from 0 to 182 F cm−3 under 1 sun irradiation because of the excellent solar light absorption and efficient solar–thermal energy conversion of graphene oxide, preventing the aqueous electrolyte from freezing. The flexible supercapacitor exhibits a long cycle life, good bending resistance, reliable scalability, and ability to power visual electronics, showing great potential for outdoor electronics in cold environments.  相似文献   

5.
Advanced methods, allowing the controllable synthesis of ordered structural nanomaterials with favourable charges transfer and storage, are highly important to achieve ideal supercapacitors with high energy density. Herein, we report a microliter droplet‐based method to synthesize hierarchical‐structured metal–organic framework/graphene/carbon nanotubes hybrids. The confined ultra‐small‐volume reaction, give well‐defined hybrids with a large specific‐surface‐area (1206 m2 g?1), abundant ionic‐channels (narrow pore of 0.86 nm), and nitrogen active‐sites (10.63 %), resulting in high pore‐size utilization (97.9 %) and redox‐activity (32.3 %). We also propose a scalable microfluidic‐blow‐spinning method to consecutively generate nanofibre‐based flexible supercapacitor electrodes with striking flexibility and mechanical strength. The supercapacitors display large volumetric energy density (147.5 mWh cm?3), high specific capacitance (472 F cm?3) and stably deformable energy‐supply.  相似文献   

6.
To endow all-solid-state asymmetric supercapacitors with high energy density, cycling stability, and flexibility, we design a binder-free supercapacitor electrode by in situ growth of well-distributed broccoli-like Ni0.75Mn0.25O/C solid solution arrays on a flexible and three-dimensional Ni current collector (3D-Ni). The electrode consists of a bottom layer of compressed but still porous Ni foam with excellent flexibility and high electrical conductivity, an intermediate layer of interconnected Ni nanoparticles providing a large specific surface area for loading of active substances, and a top layer of vertically aligned mesoporous nanosheets of a Ni0.75Mn0.25O/C solid solution. The resultant 3D-Ni/Ni0.75Mn0.25O/C cathode exhibits a specific capacitance of 1657.6 mF cm−2 at 1 mA cm−2 and shows no degradation of the capacitance after 10 000 cycles at 3 mA cm−2. The assembled 3D-Ni/Ni0.75Mn0.25O/C//activated carbon asymmetric supercapacitor has a high specific capacitance of 797.7 mF cm−2 at 2 mA cm−2 and an excellent cycling stability with 85.3 % of capacitance retention after 10 000 cycles at a current density of 3 mA cm−2. The energy density and power density of the asymmetric supercapacitor are up to 6.6 mW h cm−3 and 40.8 mW cm−3, respectively, indicating a fairly promising future of the flexible 3D-Ni/Ni0.75Mn0.25O/C electrode for efficient energy storage applications.  相似文献   

7.
Fiber supercapacitors are promising energy storage devices for potential application in wearable and miniaturized portable electronics, which currently suffer from difficulties in achieving high capacitance and energy density synchronously owing to the limited specific surface area of the electrode materials and material incompatibility between the two electrodes. Herein, a strategy is developed for the manufacture of coaxial asymmetric fiber supercapacitors by wrapping a core of PVA-KOH gel electrolyte-coated Ni(OH)2@NiCo2O4/CNT fibers with MoS2@Fe2O3/CNT paper. The as-prepared coaxial fiber asymmetric supercapacitors exhibit a specific capacitance of 373 mF cm−2 (at a current density of 2 mA cm−2) and energy density of 0.13 mW h cm−2 (at a power density of 3.2 mW cm−2), and also show good rate capability, long cycle life, and excellent flexibility. This work provides the possibility for the practical application of fiber supercapacitors in wearable and portable energy storage equipment.  相似文献   

8.
《化学:亚洲杂志》2017,12(5):543-551
Vertically aligned Ni(OH)2 nanosheets were grown on carbon paper (CP) current collectors through a simple and cost‐effective hydrothermal approach. The as‐grown nanosheets are porous and highly crystallized. If used as a monolithic electrode for electrochemical water oxidation in alkaline solution, the carbon paper supported Ni(OH)2 nanosheets [CP@Ni(OH)2] exhibit high electrocatalytic activity and excellent long‐term stability. The electrode can attain an anodic current density of 20 mA cm−2 at a low overpotential of 338 mV, comparable to that of state‐of‐the‐art RuO2 nanocatalysts supported on CP (CP/RuO2) with the same catalyst loading. Significantly, CP@Ni(OH)2 shows much better long‐term stability than CP/RuO2 upon continuous galvanostatic electrolysis, particularly at a high industry‐relevant current density such as 100 mA cm−2. CP@Ni(OH)2 can sustain water oxidation at 100 mA cm−2 for 50 h without any degradation, whereas the performance of CP/RuO2 is much poorer and deteriorates gradually over time. CP@Ni(OH)2 electrodes hold substantial promise for use as low‐costing water oxidation anodes in electrolyzers.  相似文献   

9.
《化学:亚洲杂志》2017,12(15):1920-1926
An “in situ sacrifice” process was devised in this work as a room‐temperature, all‐solution processed electrochemical method to synthesize nanostructured NiOx and FeOx directly on current collectors. After electrodepositing NiZn/FeZn bimetallic textures on a copper net, the zinc component is etched and the remnant nickel/iron are evolved into NiOx and FeOx by the “in situ sacrifice” activation we propose. As‐prepared electrodes exhibit high areal capacities of 0.47 mA h cm−2 and 0.32 mA h cm−2, respectively. By integrating NiOx as the cathode, FeOx as the anode, and poly(vinyl alcohol) (PVA)‐KOH gel as the separator/solid‐state electrolyte, the assembled quasi‐solid‐state flexible battery delivers a volumetric capacity of 6.91 mA h cm−3 at 5 mA cm−2, along with a maximum energy density of 7.40 mWh cm−3 under a power density of 0.27 W cm−3 and a maximum tested power density of 3.13 W cm−3 with a 2.17 mW h cm−3 energy density retention. Our room‐temperature synthesis, which only consumes minute electricity, makes it a promising approach for large‐scale production. We also emphasize the in situ sacrifice zinc etching process used in this work as a general strategy for metal‐based nanostructure growth for high‐performance battery materials.  相似文献   

10.
Although solid-state batteries (SSBs) are high potential in achieving better safety and higher energy density, current solid-state electrolytes (SSEs) cannot fully satisfy the complicated requirements of SSBs. Herein, a covalent organic framework (COF) with multi-cationic molecular chains (COF-MCMC) was developed as an efficient SSE. The MCMCs chemically anchored on COF channels were generated by nano-confined copolymerization of cationic ionic liquid monomers, which can function as Li+ selective gates. The coulombic interaction between MCMCs and anions leads to easier dissociation of Li+ from coordinated states, and thus Li+ transport is accelerated. While the movement of anions is restrained due to the charge interaction, resulting in a high Li+ conductivity of 4.9×10−4 S cm−1 and Li+ transference number of 0.71 at 30 °C. The SSBs with COF-MCMC demonstrate an excellent specific energy density of 403.4 Wh kg−1 with high cathode loading and limited Li metal source.  相似文献   

11.
To avoid an enormous energy crisis in the not-too-distant future, it be emergent to establish high-performance energy storage devices such as supercapacitors. For this purpose, a three-dimensional (3D) heterostructure of Co3O4 and Co3S4 on nickel foam (NF) that is covered by reduced graphene oxide (rGO) has been prepared by following a facile multistep method. At first, rGO nanosheets are deposited on NF under mild hydrothermal conditions to increase the surface area. Subsequently, nanowalls of cobalt oxide are electro-deposited on rGO/Ni foam by applying cyclic-voltammetry (CV) under optimized conditions. Finally, for the synthesis of Co3O4@Co3S4 nanocomposite, the nanostructure of Co3S4 was fabricated from Co3O4 nanowalls on rGO/NF by following an ordinary hydrothermal process through the sulfurization for the electrochemical application. The samples are characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The obtained sample delivers a high capacitance of 13.34 F cm−2 (5651.24 F g−1) at a current density of 6 mA cm−2 compared to the Co3O4/rGO/NF electrode with a capacitance of 3.06 F cm−2 (1230.77 F g−1) at the same current density. The proposed electrode illustrates the superior electrochemical performance such as excellent specific energy density of 85.68 W h Kg−1, specific power density of 6048.03 W kg−1 and a superior cycling performance (86% after 1000 charge/discharge cycles at a scan rate of 5 mV s−1). Finally, by using Co3O4 @Co3S4/rGO/NF and the activated carbon-based electrode as positive and negative electrodes, respectively, an asymmetric supercapacitor (ASC) device was assembled. The fabricated ASC provides an appropriate specific capacitance of 79.15 mF cm−2 at the applied current density of 1 mA cm−2, and delivered an energy density of 0.143 Wh kg−1 at the power density of 5.42 W kg−1.  相似文献   

12.
The development of alternative electrocatalysts exhibiting high activity in the oxygen reduction reaction (ORR) is vital for the deployment of large-scale clean energy devices, such as fuel cells and zinc–air batteries. N-doped carbon materials offer a promising platform for the design and synthesis of electrocatalysts due to their high ORR activity, high surface area, and tunable porosity. In this study, materials in which MnO nanoparticles are entrapped in N-doped mesoporous carbon (MnO/NC) were developed as electrocatalysts for the ORR, and their performances were evaluated in zinc–air batteries. The obtained carbon materials had large surface area and high electrocatalytic activity toward the ORR. The carbon compounds were fabricated by using NaCl as template in a one-pot process, which significantly simplifies the procedure for preparing mesoporous carbon materials and in turn reduces the total cost. A primary zinc–air battery based on this material exhibits an open-circuit voltage of 1.49 V, which is higher than that of conventional zinc–air batteries with Pt/C (Pt/C cell) as ORR catalyst (1.41 V). The assembled zinc–air battery delivered a peak power density of 168 mW cm−2 at a current density of about 200 mA cm−2, which is higher than that of an equivalent Pt/C cell (151 mW cm−2 at a current density of ca. 200 mA cm−2). The electrocatalytic data revealed that MnO/NC is a promising nonprecious-metal ORR catalyst for practical applications in metal–air batteries.  相似文献   

13.
Hybrid materials have obtained well-deserved attention for energy storage devices, because they show high capacitances and high energy densities induced by the synergistic effect between complementary components. Polyoxometalate-based metal–organic frameworks (POMOFs) possess the abundant redox-active sites and ordered structures of polyoxometalates (POMs) and metal–organic frameworks (MOFs), respectively. Here, an asymmetric supercapacitor (ASC) NENU-5/PPy/60//FeMo/C was fabricated in which both its electrodes are prepared from POMOF precursors. A typical POMOF material, NENU-5, was first connected with polypyrrole (PPy) through electrodeposition to form the cathode material NENU-5/PPy. Another representative POMOFs material, PMo12@MIL-100, was carbonized to obtain the anode material FeMo/C. Cathode NENU-5/PPy exhibited an extraordinary capacitance of 508.62 F g−1 (areal capacitance: 2034.51 mF cm−2). In addition, anode FeMo/C shows excellent cyclic stability attributed to its unique structure. Finally, benefiting from the outstanding capacitances and structural merits of the anode and cathode, assembled asymmetric supercapacitor NENU-5/PPy/60//FeMo/C achieves an energy density of 1.12 mWh cm−3 at a power density output of 27.78 mW cm−3, as well as a notable life of 10 000 cycles with an capacity retention of 80.62 %. Thus, the unique ASC is strongly competitive in high capacitance, long cycle life, and high energy-required energy storage devices.  相似文献   

14.
Syngas (CO/H2) is a feedstock for the production of a variety of valuable chemicals and liquid fuels, and CO2 electrochemical reduction to syngas is very promising. However, the production of syngas with high efficiency is difficult. Herein, we show that defective indium selenide synthesized by an electrosynthesis method on carbon paper (γ-In2Se3/CP) is an extremely efficient electrocatalyst for this reaction. CO and H2 were the only products and the CO/H2 ratio could be tuned in a wide range by changing the applied potential or the composition of the electrolyte. In particular, using nanoflower-like γ-In2Se3/CP (F-γ-In2Se3/CP) as the electrode, the current density could be as high as 90.1 mA cm−2 at a CO/H2 ratio of 1:1. In addition, the Faradaic efficiency of CO could reach 96.5 % with a current density of 55.3 mA cm−2 at a very low overpotential of 220 mV. The outstanding electrocatalytic performance of F-γ-In2Se3/CP can be attributed to its defect-rich 3D structure and good contact with the CP substrate.  相似文献   

15.
Recently, hydrovoltaic technology emerged as a novel renewable energy harvesting method, which dramatically extends the capability to harvest water energy. However, the urgent issue restricting its device performance is poor carrier transport properties of the solid surface if large charged interface is considered simultaneously. Herein, a hydrovoltaic device based on silicon nanowire arrays (SiNWs), which provide large charged surface/volume ratio and excellent carrier transport properties, yields sustained electricity by a carrier concentration gradient induced by evaporation-induced water flow inside nanochannels. The device can yield direct current with a short-circuit current density of over 55 μA cm−2, which is three orders larger than a previously reported analogous device (approximately 40 nA cm−2). Moreover, it exhibits a constant output power density of over 6 μW cm−2 and an open-circuit voltage of up to 400 mV. Our finding may pave a way for developing energy-harvesting devices from ubiquitous evaporation-driven internal water flow in nature with semiconductor material of silicon.  相似文献   

16.
The design of complex heterostructured electrode materials that deliver superior electrochemical performances to their individual counterparts has stimulated intensive research on configuring supercapacitors with high energy and power densities. Herein we fabricate hierarchical tectorum‐like α‐Fe2O3/polypyrrole (PPy) nanoarrays (T‐Fe2O3/PPy NAs). The 3D, and interconnected T‐Fe2O3/PPy NAs are successfully grown on conductive carbon cloth through an easy self‐sacrificing template and in situ vapor‐phase polymerization route under mild conditions. The electrode made of the T‐Fe2O3/PPy NAs exhibits a high areal capacitance of 382.4 mF cm−2 at a current density of 0.5 mA cm−2 and excellent reversibility. The solid‐state asymmetric supercapacitor consisting of T‐Fe2O3/PPy NAs and MnO2 electrodes achieves a high energy density of 0.22 mWh cm−3 at a power density of 165.6 mW cm−3.  相似文献   

17.
Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high-performance CAs on a large scale in a simple and sustainable manner. We report an eco-friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework-8 (ZIF-8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF-8/AG-derived nitrogen-doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm−3, a high specific surface area of 516 m2 g−1, and a large pore volume of 0.58 cm−3 g−1. The resulting CAs exhibit significant potential for application in the adsorption of organic pollutants.  相似文献   

18.
Conducting polymer hydrogels that are capable of contacting with electrolytes at the molecular level, represent an important electrode material. However, the fabrication of self-standing hydrogels merely composed of conducting polymers is still challenging owing to the absence of reliable methods. Herein, a novel and facile macromolecular interaction assisted route is reported to fabricate self-standing hydrogels consisting of polyaniline (PANi: providing high electrochemical activity) and poly(3,4-ethylenedioxythiophene) (PEDOT: enabling high electronic conductivity). Owing to the synergistic effect between them, the self-standing hydrogels possess good mechanical properties and electronic/electrochemical performances, making them an excellent potential electrode for solid-state energy storage devices. A proof-of-concept all-hydrogel-state supercapacitor is fabricated, which exhibits a high areal capacitance of 808.2 mF cm−2, and a high energy density of 0.63 mWh cm−3 at high power density of 28.42 mW cm−3, superior to many recently reported conducting polymer hydrogels based supercapacitors. This study demonstrates a novel promising strategy to fabricate self-standing conducting polymer hydrogels.  相似文献   

19.
In this paper, we present the study of preparation and ionic conductance for an intercalated hybrid of kaolinite with potassium dihydrogen. The intercalation efficiency is high up to ca. 90%. The intercalated hybrid has been characterized by powder X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. The ionic conductivity (σ) of the hybrid material is strongly dependent on the moisture in the environment, with σ = 8.4 × 10−10 S cm−1 at 293 K and gradually increases to 7.16 × 10−9 S cm−1 under N2 atmosphere (anhydrous environment) at 353 K as well as an activation energy of Ea = 0.618 e V, whereas σ = 2.19 × 10−4 S cm−1 at 100% relative humidity and 293 K with Ea = 0.44 eV. The mechanism that the moisture affects the ionic conductance of the intercalated hybrid is further discussed.  相似文献   

20.
High proton conducting electrolytes with mechanical moldability are a key material for energy devices. We propose an approach for creating a coordination polymer (CP) glass from a protic ionic liquid for a solid-state anhydrous proton conductor. A protic ionic liquid (dema)(H2PO4), with components which also act as bridging ligands, was applied to construct a CP glass (dema)0.35[Zn(H2PO4)2.35(H3PO4)0.65]. The structural analysis revealed that large Zn–H2PO4/H3PO4 coordination networks formed in the CP glass. The network formation results in enhancement of the properties of proton conductivity and viscoelasticity. High anhydrous proton conductivity (σ = 13.3 mS cm−1 at 120 °C) and a high transport number of the proton (0.94) were achieved by the coordination networks. A fuel cell with this CP glass membrane exhibits a high open-circuit voltage and power density (0.15 W cm−2) under dry conditions at 120 °C due to the conducting properties and mechanical properties of the CP glass.

A proton-conducting coordination polymer glass derived from a protic ionic liquid works as a moldable solid electrolyte and the anhydrous fuel cell showed IV performance of 0.15 W cm−2 at 120 °C.  相似文献   

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