Flexible battery with a smart electrochromic function of changing color in the electrochemical process reveals great application potentials in the field of intelligent electronics. However, Ni//Zn ...battery with an electricity visual alerting function has seldom been reported by now. Herein, we designed a flexible Ni//Zn battery, assembled by the NiCo bimetallic hydroxide/Ni/indium tin oxide (NiCo BH/Ni/ITO) flexible electrode with an electrochromic feature. By optimizing the thickness of the middle Ni layer, the NiCo BH/Ni/ ITO electrode shows a coloration efficiency of 59.89 cm
2
C
−1
and a capacity of 7.15 µA h cm
−2
at a current density of 0.1 mA cm
−2
. Correspondingly, the flexible electrochromic Ni//Zn battery shows a high energy density of 12.69 µW h cm
−2
at a power density of 160 µW cm
−2
, outperforming those of transparent flexible supercapacitors and electrochromic batteries reported in literatures. Moreover, the flexible electrochromic Ni//Zn battery displays reversible color change during charging and discharging processes, rendering it a novel function to monitor the battery residual electricity by visual inspection.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
As an important part of artificial intelligence, electronic skin has received more and more attention recently. However, two serious issues, slow self-healing and lack of direction recognition, have ...limited the burgeoning of electronic skin largely. Herein, for the first time we report a dual network flexible hydrogel, which was synthesized
via
cross-linking polyvinyl alcohol (PVA) and polyethylenimine (PEI) with 4-formylbenzoboric acid (Bn) to form a polymer network and then incorporating MXene into the polymer network. Due to the synergy of multiple reversible dynamic covalent bonds and supramolecular interactions, the PVA/Bn/PEI/MXene (PBPM) hydrogel exhibits direction-aware and ultrafast self-healing abilities (self-healing time ∼0.06 s) as well as rapid response performance (signal response time ∼0.12 s). Furthermore, an electronic skin strain sensor assembled by using the PBPM hydrogel can not only efficiently detect the movements in different parts of the prosthetic person body but also specifically identify the directions of the movements including head-down/up and wrist-down/up. The flexible PBPM hydrogel in this work has shown great potential in the applications of artificial skin, soft robots, health monitoring and human-machine exchange interfaces.
A dual network flexible electronic skin hydrogel with direction-recognition and ultrafast self-healing ability was prepared and applied for strain sensors.
Layered double hydroxides (LDHs) have shown remarkable potentials in supercapacitors for their highly-redox capacitance. However, the poor contact with substrate, slow charge transfer and ion ...diffusion, and low electrical conductivity limit their capacitor performance. In this work, a flexible free-standing supercapacitor was designed, with in-situ grown hollow-structured NiCo layered double hydroxide (H–NiCo LDH) as the active material based on a partial Ni ion substitution of Co ion in ZIF-67, and flexible carbon material as the substrate. Systematical investigation has been conducted in terms of nanostructures of the active material NiCo LDH (hollow or laminar structure) and flexible carbon substrates (acidified carbon cloth or acidified carbon fibers). A hollow-structured NiCo LDH@acidified carbon cloth (H–NiCo LDH@ACC) sample showed a promising capacity of 1377 mC/cm2 (3060 mF/cm2) at 1 mA/cm2, a low charge transfer resistance of 0.15 Ω, a capacity retention of 70% and a coulombic efficiency retention of 99% upon 10,000 cycles at 80 mA/cm2. PDMS-sealed solid-state H–NiCo LDH@ACC//AC devices were fabricated with an energy density of 0.0708 mWh/cm2 at a power density of 0.7 mW/cm2, with no obvious capacity decrease upon bending angles from 0° to 180°. SEM, EDS, XPS, and XRD analyses indicated the H–NiCo LDH has been in-situ grown on flexible carbon substrates. Hollow-structured LDH accelerated charge transfer and ion diffusion compared with a laminar-structured LDH. Acidified carbon cloth (ACC) showed better electrical conductivity compared with the biomass-derived acidified carbon fibers. Thus, a H–NiCo LDH@ACC is proposed as a promising candidate of a flexible supercapacitor.
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•Hollow-structured NiCo layered double hydroxide (LDH) was in-situ grown on flexible carbon substrate for supercapacitor.•Hollow-structured LDH accelerated charge transfer and ion diffusion compared with a laminar-structured LDH.•Acidified carbon cloth showed better electrical conductivity compared with the acidified carbon fibers as substrate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In order to enhance the sodium ion storage performance of biomass-derived carbon anode materials, a surface functionalization strategy was employed through a simple acid etching method on porous ...carbon. The resulting functionalized carbon exhibits a hierarchically porous structure, expanded interlayer spacing, and oxygen-containing functional groups. The redox reactions occurring at the surface between Na ions and carbonyl groups provide additional sites for sodium ion storage, thereby improving cycling capacity and rate capability. Theoretical calculations and electrochemical tests further demonstrate that the functionalized carbon can increase the surface-controlled sodium storage capacity by modifying the transport and adsorption processes of sodium ions. After 200 cycles at a current density of 100 mA g−1, the carbon anode, which was surface-functionalized with an etching time of 6 h, achieve a high reversible capacity of 273 mA h g−1. Furthermore, it displays improved rate performance with a capacity of 194 mA h g−1 at a high current density of 2 A g−1 for sodium-ion batteries. This study introduces an effective and general strategy for the cost-effective and large-scale synthesis of carbon anode materials for sodium-ion batteries.
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•A surface functionalized strategy was carried out for porous carbon by acid etching.•Good Na+ storage capacity is obtained due to porous structure and surface action.•Surface reactions between Na+ and carbonyl groups enhance cycling and rate capacity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Flexibility and lightweight are promising research topics for space science and technology, which benefit to reduce load, reduce volume, and integrate device. However, most photoelectronic devices on ...spacecraft are rigid devices now, because the space environment consists of irradiations and thermal cycling, with higher requirements for flexible photoelectronic materials and devices. The main bottlenecks include: the synthesis of space-durable packaging materials, the fabrication and packaging of flexible photoelectronic devices, and the effective investigation method for irradiation mechanism analysis. In view of these problems, this review presents the synthesis of bulk-phase silicon-reinforced yellow and transparent polyimides with space durability, the optical modulation of bulk-phase silicon-reinforced polyimide to ultra-black film and flexible color filters, the electrical modulation of bulk-phase silicon-reinforced polyimide into flexible transparent electrode, the integration of the bulk-phase silicon-reinforced transparent polyimide and flexible triple-junction GaAs thin-film solar cell, and the exploration of general investigation methods for irradiation mechanism based on the penetration depth and damage modes including atomic oxygen, ultraviolet, electron, proton, and thermal cycling. The material synthesis, device fabrication, and mechanism analysis method focus on the core scientific problems of space-durable flexible lightweight photoelectronic materials and devices, leading the development direction of flexible and lightweight space science and technology.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Covalent organic frameworks (COFs) with customizable geometry and redox centers are an ideal candidate for supercapacitors and hybrid capacitive deionization (HCDI). However, their poor intrinsic ...conductivity and micropore-dominated pore structures severely impair their electrochemical performance, and the synthesis process using organic solvents brings serious environmental and cost issues. Herein, a 2D redox-active pyrazine-based COF (BAHC-COF) was anchored on the surface of graphene in a solvent-free strategy for heterointerface regulation. The as-prepared BAHC-COF/graphene (BAHCGO) nanohybrid materials possess high-speed charge transport offered by the graphene carrier and accelerated electrolyte ion migration within the BAHC-COF, allowing ions to effectively occupy ion storage sites inside BAHC. As a result, the BAHCGO//activated carbon asymmetric supercapacitor achieves a high energy output of 61.2 W h kg
and a satisfactory long-term cycling life. More importantly, BAHCGO-based HCDI possesses a high salt adsorption capacity (SAC) of 67.5 mg g
and excellent long-term desalination/regeneration stability. This work accelerates the application of COF-based materials in the fields of energy storage and water treatment.
A hollow tubular NiCo LDH@AgNW with improved conductivity and enhanced redox kinetics for high power density Ni//Zn battery.
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Flexible aqueous Ni//Zn batteries have attracted much ...attention as promising candidates for energy storage in the field of flexible electronics. However, the Ni-based cathodes still face the challenges of poor conductivity, confined charge/mass transfer, and non-flexibility. In this work, we designed a hollow tubular structure consisting of a conductive silver nanowire (AgNW) wrapped by active NiCo layered double hydroxide (LDH), for enhancing the electrical conductivity, improving the charge/mass transfer kinetics, and facilitating the ion penetration. By optimizing the contents of Ni, Co and AgNW, the Ni4Co LDH@Ag1.5NW composite shows a maximum specific capacity of 115.83 mAh g−1 at 0.1 A g−1 measured in a two-electrode system. Highlightingly, the flexible aqueous Ni//Zn battery assembled by Ni4Co LDH@Ag1.5NW interwoven with multi-walled carbon nanotube cathode and Zn foil anode realizes a high power density of 160 μW cm−2 at the energy density of 23.14 μWh cm−2, which is superior compared with those of oxide/hydroxide based devices and even higher than those of many carbon-based supercapacitors, showing its promising potentials for flexible energy storage applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Nickel-based metal-organic frameworks (Ni-MOFs) have attracted increasing attention in non-enzymatic glucose sensing. However, the insufficient active Ni cation sites from a stacked MOF layer, the ...unclear Ni catalysis mechanism, and the severe liquid alkaline electrolyte remain challenging for practical applications. In this work, the sonication-induced longitudinal-expansion of Ni-MOFs increases the active nickel ion sites, which not only enhances the current response to glucose detection, but also shows the oxidation peak evolution of nickel ions with different sonication times, revealing the mechanism of different glucose detection channels. The Ni-MOF sonicated for 60 min (60 min Ni-MOF) displays enhanced Ni(
iii
)/Ni(
ii
) and more significant Ni(
iv
)/Ni(
iii
) double nickel cation channels for catalyzing glucose into glucolactone compared to the 0 min Ni-MOF (without sonication), showing optimized glucose detection ability with a high sensitivity of 3297.10 μA mM
−1
cm
−2
, a low detection limit of ∼8.97 μM (signal-to-noise = 3) and a wide linear response range from 10 to 400 μM from the cyclic voltammetry test as well as a high sensitivity of 3.03 μA mM
−1
cm
−2
, a low detection limit of ∼1.16 μM (signal-to-noise = 3) and a wide linear response range from 10 to 2000 μM from the chronoamperometry test. More importantly, an all-solid-state glucose biosensor using a PVA/NaOH solid-state electrolyte and a disposable 60 min Ni-MOF working electrode is assembled for non-enzymatic sweat glucose detection.
A longitudinally expanded Ni-Based metal-organic framework with enhanced double nickel cation catalysis reaction channels was used for a non-enzymatic sweat glucose biosensor.
Purpose
This study aims to evaluate the protection performance of zinc as sacrificial anode for ABS A steel in the presence of H2S under different temperatures, pH and salinities.
...Design/methodology/approach
In this paper, weight loss measurements and electrochemical measurements are used to evaluate the corrosion degree of zinc and ABS A steel.
Findings
Under the conditions involved in this work, it is shown that zinc is a nice sacrificial anode with the reason of its stable potential and excellent anode current efficiency according to the relevant standard. And it is also found that the hydrogen evolution does not occur on ABS A steel specimens. The potential difference between cathode and anode is suitable; thus, it can be concluded that each steel is well protected.
Originality/value
To the best of the authors’ knowledge, no other study has analyzed the protection mechanism and effect of zinc as sacrificial anode in H2S-containing environments under high temperature at present.
Covalent organic frameworks (COFs) with customizable geometry and redox centers are an ideal candidate for supercapacitors and hybrid capacitive deionization (HCDI). However, their poor intrinsic ...conductivity and micropore-dominated pore structures severely impair their electrochemical performance, and the synthesis process using organic solvents brings serious environmental and cost issues. Herein, a 2D redox-active pyrazine-based COF (BAHC-COF) was anchored on the surface of graphene in a solvent-free strategy for heterointerface regulation. The as-prepared BAHC-COF/graphene (BAHCGO) nanohybrid materials possess high-speed charge transport offered by the graphene carrier and accelerated electrolyte ion migration within the BAHC-COF, allowing ions to effectively occupy ion storage sites inside BAHC. As a result, the BAHCGO//activated carbon asymmetric supercapacitor achieves a high energy output of 61.2 W h kg
−1
and a satisfactory long-term cycling life. More importantly, BAHCGO-based HCDI possesses a high salt adsorption capacity (SAC) of 67.5 mg g
−1
and excellent long-term desalination/regeneration stability. This work accelerates the application of COF-based materials in the fields of energy storage and water treatment.
A 2D redox-active pyrazine-based COF was solvent-free anchored on graphene for heterointerface regulation, displaying exciting energy storage and desalination performances.
