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1.
On‐chip microsupercapacitors (MSCs) have application in powering microelectronic devices. Most of previous MSCs are made from carbon materials, which have high power but low energy density. In this work, 3D interdigital Au/MnO2/Au stacked MSCs have been fabricated based on laser printed flexible templates. This vertical‐stacked electrode configuration can effectively increase the contact area between MnO2 active layer and Au conductive layer, and thus improve the electron transport and electrolyte ion diffusion, resulting in enhanced pseudocapacitive performance of MnO2. The stacked electrode can achieve an areal capacitance up to 11.9 mF cm?2. Flexible and all‐solid‐state MSCs are assembled based on the sandwich hybrid electrodes and PVA/LiClO4 gel electrolyte and show outstanding high‐rate capacity and mechanical flexibility. The laser printing technique in this work combined with the physical sputtering and electrodeposition allows fabrication of MSC array with random sizes and patterns, making them promising power sources for small‐scale flexible microelectronic energy storage systems (e.g., next‐generation smart phones).  相似文献   

2.
High‐performance wearable supercapactors (SCs) are gaining prominence as portable energy storage devices. To further enhance both energy and power density, the significant relationship between structure and performance inspires a delicate design of 3D patternable supercapacitors with a hierarchical architecture of porous conductive fibers composited with pseudocapacitive materials. In this work, the polypyrrole nanowires arrays decorated 3D graphite felt fiber assembly is initially fabricated as the conductive scaffold, followed by the distribution of the highly conductive and pseudocapacitive NiCoSe2 nanoparticles. Moreover, to realize the goal of standardized batch and pattern processing of the wearable SCs, laser engraving and silicone sealing techniques are employed, and SC devices with different patterns are successfully fabricated and encapsulated. Notably, the resulting SCs exhibit both stable electrochemical performance and effective waterproof properties, with the highest specific capacitance of 5.21 F cm?3 (113.36 F g?1) at the current density of 0.025 A cm?3 (0.5 F g?1), and the highest energy density of 1.09 mWh cm?3 (22.14 Wh kg?1) at a power density of 16.5 mW cm?3 (358.7 W kg?1).  相似文献   

3.
Compactness and versatility of fiber‐based micro‐supercapacitors (FMSCs) make them promising for emerging wearable electronic devices as energy storage solutions. But, increasing the energy storage capacity of microscale fiber electrodes, while retaining their high power density, remains a significant challenge. Here, this issue is addressed by incorporating ultrahigh mass loading of ruthenium oxide (RuO2) nanoparticles (up to 42.5 wt%) uniformly on nanocarbon‐based microfibers composed largely of holey reduced graphene oxide (HrGO) with a lower amount of single‐walled carbon nanotubes as nanospacers. This facile approach involes (1) space‐confined hydrothermal assembly of highly porous but 3D interconnected carbon structure, (2) impregnating wet carbon structures with aqueous Ru3+ ions, and (3) anchoring RuO2 nanoparticles on HrGO surfaces. Solid‐state FMSCs assembled using those fibers demonstrate a specific volumetric capacitance of 199 F cm?3 at 2 mV s?1. Fabricated FMSCs also deliver an ultrahigh energy density of 27.3 mWh cm?3, the highest among those reported for FMSCs to date. Furthermore, integrating 20 pieces of FMSCs with two commercial flexible solar cells as a self‐powering energy system, a light‐emitting diode panel can be lit up stably. The current work highlights the excellent potential of nano‐RuO2‐decorated HrGO composite fibers for constructing micro‐supercapacitors with high energy density for wearable electronic devices.  相似文献   

4.
Additive manufacturing (AM) technologies appear as a paradigm for scalable manufacture of electrochemical energy storage (EES) devices, where complex 3D architectures are typically required but are hard to achieve using conventional techniques. The combination of these technologies and innovative material formulations that maximize surface area accessibility and ion transport within electrodes while minimizing space are of growing interest. Herein, aqueous inks composed of atomically thin (1–3 nm) 2D Ti3C2Tx with large lateral size of about 8 µm possessing ideal viscoelastic properties are formulated for extrusion‐based 3D printing of freestanding, high specific surface area architectures to determine the viability of manufacturing energy storage devices. The 3D‐printed device achieves a high areal capacitance of 2.1 F cm?2 at 1.7 mA cm?2 and a gravimetric capacitance of 242.5 F g?1 at 0.2 A g?1 with a retention of above 90% capacitance for 10 000 cycles. It also exhibits a high energy density of 0.0244 mWh cm?2 and a power density of 0.64 mW cm?2 at 4.3 mA cm?2. It is anticipated that the sustainable printing and design approach developed in this work can be applied to fabricate high‐performance bespoke multiscale and multidimensional architectures of functional and structural materials for integrated devices in various applications.  相似文献   

5.
2D carbon nanomaterials such as graphene and its derivatives, have gained tremendous research interests in energy storage because of their high capacitance and chemical stability. However, scalable synthesis of ultrathin carbon nanosheets with well‐defined pore architectures remains a great challenge. Herein, the first synthesis of 2D hierarchical porous carbon nanosheets (2D‐HPCs) with rich nitrogen dopants is reported, which is prepared with high scalability through a rapid polymerization of a nitrogen‐containing thermoset and a subsequent one‐step pyrolysis and activation into 2D porous nanosheets. 2D‐HPCs, which are typically 1.5 nm thick and 1–3 µm wide, show a high surface area (2406 m2 g?1) and with hierarchical micro‐, meso‐, and macropores. This 2D and hierarchical porous structure leads to robust flexibility and good energy‐storage capability, being 139 Wh kg?1 for a symmetric supercapacitor. Flexible supercapacitor devices fabricated by these 2D‐HPCs also present an ultrahigh volumetric energy density of 8.4 mWh cm?3 at a power density of 24.9 mW cm?3, which is retained at 80% even when the power density is increased by 20‐fold. The devices show very high electrochemical life (96% retention after 10000 charge/discharge cycles) and excellent mechanical flexibility.  相似文献   

6.
Compared to single metallic Ni or Co phosphides, bimetallic Ni–Co phosphides own ameliorative properties, such as high electrical conductivity, remarkable rate capability, upper specific capacity, and excellent cycle performance. Here, a simple one‐step solvothermal process is proposed for the synthesis of bouquet‐like cobalt‐doped nickel phosphite (Ni11(HPO3)8(OH)6), and the effect of the structure on the pseudocapacitive performance is investigated via a series of electrochemical measurements. It is found that when the cobalt content is low, the glycol/deionized water ratio is 1, and the reaction is under 200 °C for 20 h, the morphology of the sample is uniform and has the highest specific surface area. The cobalt‐doped Ni11(HPO3)8(OH)6 electrode presents a maximum specific capacitance of 714.8 F g?1. More significantly, aqueous and solid‐state flexible electrochemical energy storage devices are successfully assembled. The aqueous device shows a high energy density of 15.48 mWh cm?2 at the power density of 0.6 KW cm?2. The solid‐state device shows a high energy density of 14.72 mWh cm?2 at the power density of 0.6 KW cm?2. These excellent performances confirm that the cobalt‐doped Ni11(HPO3)8(OH)6 are promising materials for applications in electrochemical energy storage devices.  相似文献   

7.
Solution‐based techniques are considered as a promising strategy for scalable fabrication of flexible electronics owing to their low‐cost and high processing speed. The key to the success of these techniques is dominated by the ink formulation of active nanomaterials. This work successfully prepares a highly concentrated two dimensional (2D) crystal ink comprised of ultrathin nickel hydroxide (Ni(OH)2) nanosheets with an average lateral size of 34 nm. The maximum concentration of Ni(OH)2 nanosheets in water without adding any additives reaches as high as 50 mg mL?1, which can be printed on arbitrary substrates to form Ni(OH)2 thin films. As a proof‐of‐concept application, Ni(OH)2 nanosheet ink is coated on commercialized carbon fiber yarns to fabricate wearable energy storage devices. The thus‐fabricated hybrid supercapacitors exhibit excellent flexibility with a capacitance retention of 96% after 5000 bending–unbending cycles, and good weavability with a high volumetric capacitance of 36.3 F cm?3 at a current density of 0.4 A cm?3, and an energy density of 11.3 mWh cm?3 at a power density of 0.3 W cm?3. As a demonstration of practical application, a red light emitting diode can be lighted up by three hybrid devices connected in series.  相似文献   

8.
2D metal‐porphyrin frameworks (MPFs) are attractive for advanced energy storage devices. However, the inferior conductivity and low structural stability of MPFs seriously limit their application as flexible free‐standing electrodes with high performance. Here, for the first time, an interlayer hydrogen‐bonded MXene/MPFs film is proposed to overcome these disadvantages by intercalation of highly conductive MXene nanosheets into MPFs nanosheets via a vacuum‐assisted filtration technology. The alternant insertion of MXene and MPFs affords 3D interconnected “MPFs‐to‐MXene‐to‐MPFs” conductive networks to accelerate the ionic/electronic transport rates. Meanwhile, the interlayer hydrogen bonds (F···H? O and O···H? O) contribute a high chemical stability due to a favorable tolerance to volume change caused by phase separation and structural collapse during the charge/discharge process. The synergistic effect makes MXene/MPFs film deliver a capacitance of 326.1 F g?1 at 0.1 A g?1, 1.64 F cm?2 at 1 mA cm?2, 694.2 F cm?3 at 1 mA cm?3 and a durability of about 30 000 cycles. The flexible symmetric supercapacitor shows an areal capacitance of 408 mF cm?2, areal energy density of 20.4 µW h cm?2, and capacitance retention of 95.9% after 7000 cycles. This work paves an avenue for the further exploration of 2D MOFs in flexible energy storage devices.  相似文献   

9.
Flexible supercapacitors have shown enormous potential for portable electronic devices. Herein, hierarchical 3D all‐carbon electrode materials are prepared by assembling N‐doped graphene quantum dots (N‐GQDs) on carbonized MOF materials (cZIF‐8) interweaved with carbon nanotubes (CNTs) for flexible all‐solid‐state supercapacitors. In this ternary electrode, cZIF‐8 provides a large accessible surface area, CNTs act as the electrical conductive network, and N‐GQDs serve as highly pseudocapactive materials. Due to the synergistic effect and hierarchical assembly of these components, N‐GQD@cZIF‐8/CNT electrodes exhibit a high specific capacitance of 540 F g?1 at 0.5 A g?1 in a 1 m H2SO4 electrolyte and excellent cycle stability with 90.9% capacity retention over 8000 cycles. The assembled supercapacitor possesses an energy density of 18.75 Wh kg?1 with a power density of 108.7 W kg?1. Meanwhile, three supercapacitors connected in series can power light‐emitting diodes for 20 min. All‐solid‐state N‐GQD@cZIF‐8/CNT flexible supercapacitor exhibits an energy density of 14 Wh kg?1 with a power density of 89.3 W kg?1, while the capacitance retention after 5000 cycles reaches 82%. This work provides an effective way to construct novel electrode materials with high energy storage density as well as good cycling performance and power density for high‐performance energy storage devices via the rational design.  相似文献   

10.
Self‐powered charging systems in conjunction with renewable energy conversion and storage devices have attracted promising attention in recent years. In this work, a prolific approach to design a wind/solar‐powered rechargeable high‐energy density pouch‐type hybrid supercapacitor (HSC) is proposed. The pouch‐type HSC is fabricated by engineering nature‐inspired nanosliver (nano‐Ag) decorated Ni0.67Co0.33S forest‐like nanostructures on Ni foam (nano‐Ag@NCS FNs/Ni foam) as a battery‐type electrode and porous activated carbon as a capacitive‐type electrode. Initially, the core–shell‐like NCS FNs/Ni foam is prepared via a single‐step wet‐chemical method, followed by a light‐induced growth of nano‐Ag onto it for enhancing the conductivity of the composite. Utilizing the synergistic effects of forest‐like nano‐Ag@NCS FNs/Ni foam as a composite electrode, the fabricated device shows a maximum capacitance of 1104.14 mF cm?2 at a current density of 5 mA cm?2 and it stores superior energy and power densities of 0.36 mWh cm?2 and 27.22 mW cm?2, respectively along with good cycling stability, which are higher than most of previous reports. The high‐energy storage capability of HSCs is further connected to wind fans and solar cells to harvest renewable energy. The wind/solar charged HSCs can effectively operate various electronic devices for a long time, enlightening its potency for the development of sustainable energy systems.  相似文献   

11.
Storing more energy in a limited device area is very challenging but crucial for the applications of flexible and wearable electronics. Metal vanadates have been regarded as a fascinating group of materials in many areas, especially in lithium‐ion storage. However, there has not been a versatile strategy to synthesize flexible metal vanadate hybrid nanostructures as binder‐free anodes for Li‐ion batteries so far. A convenient and versatile synthesis of MxVyOx+2.5y@carbon cloth (M = Mn, Co, Ni, Cu) composites is proposed here based on a two‐step hydrothermal route. As‐synthesized products demonstrate hierarchical proliferous structure, ranging from nanoparticles (0D), and nanobelts (1D) to a 3D interconnected network. The metal vanadate/carbon hybrid nanostructures exhibit excellent lithium storage capability, with a high areal specific capacity up to 5.9 mAh cm?2 (which equals to 1676.8 mAh g?1) at a current density of 200 mA g?1. Moreover, the nature of good flexibility, mixed valence states, and ultrahigh mass loading density (over 3.5 mg cm?2) all guarantee their great potential in compact energy storage for future wearable devices and other related applications.  相似文献   

12.
Electrochemical capacitor systems based on Al ions can offer the possibilities of low cost and high safety, together with a three‐electron redox‐mechanism‐based high capacity, and thus are expected to provide a feasible solution to meet ever‐increasing energy demands. Here, highly efficient Al‐ion intercalation into W18O49 nanowires (W18O49NWs) with wide lattice spacing and layered single‐crystal structure for electrochemical storage is demonstrated. Moreover, a freestanding composite film with a hierarchical porous structure is prepared through vacuum‐assisted filtration of a mixed dispersion containing W18O49NWs and single‐walled carbon nanotubes. The as‐prepared composite electrode exhibits extremely high areal capacitances of 1.11–2.92 F cm?2 and 459 F cm?3 at 2 mA cm?2, enhanced electrochemical stability in the Al3+ electrolyte, as well as excellent mechanical properties. An Al‐ion‐based, flexible, asymmetric electrochemical capacitor is assembled that displays a high volumetric energy density of 19.0 mWh cm?3 at a high power density of 295 mW cm?3. Finally, the Al‐ion‐based asymmetric supercapacitor is used as the power source for poly(3‐hexylthiophene)‐based electrochromic devices, demonstrating their promising capability in flexible electronic devices.  相似文献   

13.
Planar micro‐supercapacitors are attractive for system on chip technologies and surface mount devices due to their large areal capacitance and energy/power density compared to the traditional oxide‐based capacitors. In the present work, a novel material, niobium nanowires, in form of vertically aligned electrodes for application in high performance planar micro‐supercapacitors is introduced. Specific capacitance of up to 1 kF m?2 (100 mF cm?2) with peak energy and power density of 2 kJ m?2 (6.2 MJ m?3 or 1.7 mWh cm?3) and 150 kW m?2 (480 MW m?3 or 480 W cm?3), respectively, is achieved. This remarkable power density, originating from the extremely low equivalent series resistance value of 0.27 Ω (2.49 µΩ m2 or 24.9 mΩ cm2) and large specific capacitance, is among the highest for planar micro‐supercapacitors electrodes made of nanomaterials.  相似文献   

14.
Bromine‐based flow batteries are well suited for stationary energy storage due to attractive features of high energy density and low cost. However, the bromine‐based flow battery suffers from low power density and large materials consumption due to the relatively high polarization of the Br2/Br? couple on the electrodes. Herein, a self‐supporting 3D hierarchical composite electrode based on a TiN nanorod array is designed to improve the activity of the Br2/Br? couple and increase the power density of the bromine‐based flow battery. In this design, a carbon felt provides a composite electrode with a 3D electron conductive framework to guarantee high electronic conductivity, while the TiN nanorods possess excellent catalytic activity for the Br2/Br? electrochemical reaction to reduce the electrochemical polarization. Moreover, the 3D micro–nano hierarchical nanorod‐array alignment structure contributes to a high electrolyte penetration and a high ion‐transfer rate to reduce diffusion polarization. As a result, a zinc–bromine flow battery with the designed composite electrode can be operated at a current density of up to 160 mA cm?2, which is the highest current density ever reported. These results exhibit a promising strategy to fabricate electrodes for ultrahigh‐power‐density bromine‐based flow batteries and accelerate the development of bromine‐based flow batteries.  相似文献   

15.
Sodium‐ion batteries (SIBs) have gained tremendous interest for grid scale energy storage system and power energy batteries. However, the current researches of anode for SIBs still face the critical issues of low areal capacity, limited cycle life, and low initial coulombic efficiency for practical application perspective. To solve this issue, a kind of hierarchical 3D carbon‐networks/Fe7S8/graphene (CFG) is designed and synthesized as freestanding anode, which is constructed with Fe7S8 microparticles well‐welded on 3D‐crosslinked carbon‐networks and embedded in highly conductive graphene film, via a facile and scalable synthetic method. The as‐prepared freestanding electrode CFG represents high areal capacity (2.12 mAh cm?2 at 0.25 mA cm?2) and excellent cycle stability of 5000 cycles (0.0095% capacity decay per cycle). The assembled all‐flexible sodium‐ion battery delivers remarkable performance (high areal capacity of 1.42 mAh cm?2 at 0.3 mA cm?2 and superior energy density of 144 Wh kg?1), which are very close to the requirement of practical application. This work not only enlightens the material design and electrode engineering, but also provides a new kind of freestanding high energy density anode with great potential application prospective for SIBs.  相似文献   

16.
Rational designing of the composition and structure of electrode material is of great significance for achieving highly efficient energy storage and conversion in electrochemical energy devices. Herein, MoS2/NiS yolk–shell microspheres are successfully synthesized via a facile ionic liquid‐assisted one‐step hydrothermal method. With the favorable interface effect and hollow structure, the electrodes assembled with MoS2/NiS hybrid microspheres present remarkably enhanced electrochemical performance for both overall water splitting and asymmetric supercapacitors. In particular, to deliver a current density of 10 mA cm?2, the MoS2/NiS‐based electrolysis cell for overall water splitting only needs an output voltage of 1.64 V in the alkaline medium, lower than that of Pt/C–IrO2‐based electrolysis cells (1.70 V). As an electrode for supercapacitors, the MoS2/NiS hybrid microspheres exhibit a specific capacitance of 1493 F g?1 at current density of 0.2 A g?1, and remain 1165 F g?1 even at a large current density of 2 A g?1, implying outstanding charge storage capacity and excellent rate performance. The MoS2/NiS‐ and active carbon‐based asymmetric supercapacitor manifests a maximum energy density of 31 Wh kg?1 at a power density of 155.7 W kg?1, and remarkable cycling stability with a capacitance retention of approximately 100% after 10 000 cycles.  相似文献   

17.
Wearable in‐plane Zn‐based microbatteries are considered as promising micropower sources for wearable electronics due to their high capacity, low cost, high safety, and easy integration. However, their applications are severely impeded by inadequate energy density arising from unsatisfactory capacity of cathode and poor cycling stability caused by degradation of electrode materials and Zn dendrite. Additionally, the short‐circuit induced safety issue caused by Zn dendrite is still a roadblock for Zn‐based microbatteries. Herein, a textile‐based Co?Zn microbattery with ultrahigh energy density and excellent cycling stability is demonstrated. Benefiting from the fast electron transport of three‐dimensional (3D) porous Ni‐coated textile and synergistic effect from the hierarchical Co(OH)2@NiCo layered double hydroxide (LDH) core?shell electrode, the fabricated Co?Zn microbattery with high flexibility delivers superior energy/power densities of 0.17 mWh cm?2/14.4 mW cm?2, outperforming most reported micro energy storage devices. Besides, the trench‐type configuration as well as the 3D porous Zn@carbon clothes can avoid the short‐circuit‐induced safety issues, resulting in excellent cycling stability (71% after 800 cycles). The unique core?shell structure and novel configuration provide a brand‐new design strategy for high‐performance wearable in‐plane microdevices.  相似文献   

18.
Although there has been tremendous progress in exploring new configurations of zinc‐ion hybrid supercapacitors (Zn‐HSCs) recently, the much lower energy density, especially the much lower areal energy density compared with that of the rechargeable battery, is still the bottleneck, which is impeding their wide applications in wearable devices. Herein, the pre‐intercalation of Zn2+ which gives rise to a highly stable tunnel structure of ZnxMnO2 in nanowire form that are grown on flexible carbon cloth with a disruptively large mass loading of 12 mg cm?2 is reported. More interestingly, the ZnxMnO2 nanowires of tunnel structure enable an ultrahigh areal energy density and power density, when they are employed as the cathode in Zn‐HSCs. The achieved areal capacitance of up to 1745.8 mF cm?2 at 2 mA cm?2, and the remarkable areal energy density of 969.9 µWh cm?2 are comparable favorably with those of Zn‐ion batteries. When integrated into a quasi‐solid‐state device, they also endow outstanding mechanical flexibility. The truly battery‐level Zn‐HSCs are timely in filling up of the battery‐supercapacitor gap, and promise applications in the new generation flexible and wearable devices.  相似文献   

19.
Fabrication of high‐energy‐density and high‐power‐density packaged long‐cycle‐life rechargeable microbatteries remains a considerable challenge. Here, high‐performance microbatteries with high active volume fraction, thick, 3D‐structured electrodes (V2O5 cathode and Li metal anode) are realized through a combination of imprint lithography, self‐assembly, and electrodeposition. To assist the critical challenge of hermetic packaging, the microbattery is infilled with a gel electrolyte. The packaged cell exhibits high areal energy and power densities of 1.24 J cm?2 and 75.5 mW cm?2, respectively, and can be cycled 550 times in argon or 200 times in air with 75% capacity retention of the initial discharge capacity. An unpackaged cell, using a liquid electrolyte, provides a power density of 218 mW cm?2. As far as it is known, the microbatteries have the highest peak power density among all reported microbatteries.  相似文献   

20.
Supercapacitors have received increasing interest as energy storage devices due to their rapid charge–discharge rates, high power densities, and high durability. In this work, novel conjugated microporous polymer (CMP) networks are presented for supercapacitor energy storage, namely 3D polyaminoanthraquinone (PAQ) networks synthesized via Buchwald–Hartwig coupling between 2,6‐diaminoanthraquinone and aryl bromides. PAQs exhibit surface areas up to 600 m2 g?1, good dispersibility in polar solvents, and can be processed to flexible electrodes. The PAQs exhibit a three‐electrode specific capacitance of 576 F g?1 in 0.5 m H2SO4 at a current of 1 A g?1 retaining 80–85% capacitances and nearly 100% Coulombic efficiencies (95–98%) upon 6000 cycles at a current density of 2 A g?1. Asymmetric two‐electrode supercapacitors assembled by PAQs show a capacitance of 168 F g?1 of total electrode materials, an energy density of 60 Wh kg?1 at a power density of 1300 W kg?1, and a wide working potential window (0–1.6 V). The asymmetric supercapacitors show Coulombic efficiencies up to 97% and can retain 95.5% of initial capacitance undergo 2000 cycles. This work thus presents novel promising CMP networks for charge energy storage.  相似文献   

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