Perovskite solar cells(PSCs)have become the represent-atives of next generation of photovoltaics;nevertheless,their stability is insufficient for large scale deployment,particularly the reverse bias stability.Here,we ...Perovskite solar cells(PSCs)have become the represent-atives of next generation of photovoltaics;nevertheless,their stability is insufficient for large scale deployment,particularly the reverse bias stability.Here,we propose a transparent conducting oxide(TCO)and low-cost metal composite electrode to improve the stability of PSCs without sacrificing the efficiency.The TCO can block ion migrations and chemical reactions between the metal and perovskite,while the metal greatly enhances the conductivity of the composite electrode.As a result,composite electrode-PSCs achieved a power conversion efficiency(PCE)of 23.7%(certified 23.2%)and exhibited excellent stability,maintaining 95%of the initial PCE when applying a reverse bias of 4.0 V for 60 s and over 92%of the initial PCE after 1000 h continuous light soaking.This composite electrode strategy can be extended to different combinations of TCOs and metals.It opens a new avenue for improving the stability of PSCs.展开更多
Composite electrodes prepared by cation exchange resins and activated carbon(AC)were used to adsorb Ⅴ(Ⅳ)in capacitive deionization(CDI).The electrode made of middle resin size(D860/AC M)had the largest specific surf...Composite electrodes prepared by cation exchange resins and activated carbon(AC)were used to adsorb Ⅴ(Ⅳ)in capacitive deionization(CDI).The electrode made of middle resin size(D860/AC M)had the largest specific surface area and mesoporous content than two other composite electrodes.Electrochemical analysis showed that D860/AC M presents higher specific capacitance and electrical double layer capacitor than the others,and significantly lower internal diffusion impedance.Thus,D860/AC M exhibits the highest adsorption capacity and rate of Ⅴ(Ⅳ)among three electrodes.The intra-particle diffusion model fits well in the initial adsorption stage,while the liquid film diffusion model is more suitable for fitting at the later stage.The pseudo-second-order kinetic model is suited for the entire adsorption process.The adsorption of Ⅴ(Ⅳ)on the composite electrode follows that of the Freundlich isotherm.Thermodynamic analysis indicates that the adsorption of Ⅴ(Ⅳ)is an exothermic process with entropy reduction,and the electric field force plays a dominant role in the CDI process.This work aims to improve our understanding of the ion adsorption behaviors and mechanisms on the composite electrodes in CDI.展开更多
Stretchable organic light-emitting diodes(OLEDs)are important components for flexible/wearable electronics.However,the efficiency of the existing stretchable OLEDs is still much lower as compared with their rigid coun...Stretchable organic light-emitting diodes(OLEDs)are important components for flexible/wearable electronics.However,the efficiency of the existing stretchable OLEDs is still much lower as compared with their rigid counterparts,one of the main reasons being the lack of ideal flexible transparent electrodes.Herein,we propose and develop a printed embedded metal composite electrode(PEMCE)strategy that enables the fabrication of ultra-thin,highly flexible transparent electrodes with robust mechanical properties.With the flexible transparent electrodes serves as the anodes,flexible/stretchable white OLEDs have been successfully constructed,achieving a current efficiency of up to 77.4 cd A^(-1)and a maximum luminance of 34787 cd m^(-2).The current efficiency of the resulting stretchable OLEDs is the highest ever reported for flexible/stretchable white OLEDs,which is about 1.2 times higher than that of the reference rigid devices based on ITO/glass electrodes.The excellent optoelectronic properties of the printed embedded transparent electrodes and the light extraction effect of the Ag-mesh account for the significant increase in current efficiency.Remarkably,the electroluminescence performance still retains~83%of the original luminance even after bending the device 2000 cycles at a radii of~0.5 mm.More importantly,the device can withstand tensile strains of up to~100%,and even mechanical deformation of 90%tensile strain does not result in a significant loss of electroluminescence performance with current efficiency and luminance maintained at over 85%.The results confirm that the PEMCE strategy is effective for constructing ultra-flexible transparent electrodes,showing great promise for use in a variety of flexible/stretchable electronics.展开更多
This work describes the electrochemical behaviour of ibuprofen on two types of multi-walled carbon nanotubes based composite electrodes,i.e.,multi-walled carbon nanotubes-epoxy(MWCNT) and silver-modified zeolite-multi...This work describes the electrochemical behaviour of ibuprofen on two types of multi-walled carbon nanotubes based composite electrodes,i.e.,multi-walled carbon nanotubes-epoxy(MWCNT) and silver-modified zeolite-multi-walled carbon nanotubes-epoxy(AgZMWCNT) composites electrodes.The composite electrodes were obtained using two-roll mill procedure.SEM images of surfaces of the composites revealed a homogeneous distribution of the composite components within the epoxy matrix.AgZMWCNT composite electrode exhibited the better electrical conductivity and larger electroactive surface area.The electrochemical determination of ibuprofen(IBP) was achieved using AgZMWCNT by cyclic voltammetry,differential-pulsed voltammetry,square-wave voltammetry and chronoamperometry.The IBP degradation occurred on both composite electrodes under controlled electrolysis at 1.2 and 1.75 V vs.Ag/AgCl,and IBP concentration was determined comparatively by differential-pulsed voltammetry,under optimized conditions using AgZMWCNT electrode and UV-Vis spectrophotometry methods to determine the IBP degradation performance for each electrode.AgZMWCNT electrode exhibited a dual character allowing a double application in IBP degradation process and its control.展开更多
1 Results The phenomena that affect the membranes could be found in the electrodes when they operate at medium temperature,due to the utilisation of Nafion as an ionomer in the catalytic layer.An approach to improve t...1 Results The phenomena that affect the membranes could be found in the electrodes when they operate at medium temperature,due to the utilisation of Nafion as an ionomer in the catalytic layer.An approach to improve the mechanical properties of the ionomer in the catalytic layer was used: different inorganic compounds (zeolite,titania and zirconia),having different chemical-physical properties,were selected as inorganic fillers due to their water retention capacity and to act as mechanical reinforce by ...展开更多
The variation of the effective modulus of silicon composite electrodes,which is a fundamental feature to analyze the coupled mechanical–electrochemical behavior of Si-based electrodes in high-capacity lithium-ion bat...The variation of the effective modulus of silicon composite electrodes,which is a fundamental feature to analyze the coupled mechanical–electrochemical behavior of Si-based electrodes in high-capacity lithium-ion batteries,remains qualitatively controversial.To clarify the contradictory experimental results,numerical modeling of a representative volume element with silicon particles,carbon-binder domains(CBDs),and pores has been performed for the lithiation process.The key parameters for modulus variation were identified and evaluated.A mesostructure change is proposed to be a crucial mechanism that affects the modulus variation,and silicon softening is another key mechanism.Silicon softening and the decreasing CBD volume fraction collectively result in a decrease in the effective modulus of the composite,whereas an increase in the silicon volume fraction along with a decrease in porosity has the opposite effect.The findings of this work provide an in-depth and fundamental understanding of the mechanical properties of silicon composite electrodes.展开更多
Extensive research has been carried out for improved sensitivity of electroactive biofilm-based sensor(EAB-sensor),which is recognized as a useful tool in water quality early-warning.Antibiotic that is employed widely...Extensive research has been carried out for improved sensitivity of electroactive biofilm-based sensor(EAB-sensor),which is recognized as a useful tool in water quality early-warning.Antibiotic that is employed widely to treat infection has been proved feasible in this study to regulate the EAB and to increase the EAB-biosensor’s sensitivity.A novel composite electrode was prepared using azithromycin(AZM)and graphite powder(GP),namely AZM@GP electrode,and was employed as the anode in EAB-biosensor.Different dosages of AZM,i.e.,2 mg,4 mg,and 8 mg,referred to as 0.25%,0.5%and 1%AZM@GP were under examination.Results showed that EAB-biosensor was greatly benefited from appropriate dosage of AZM(0.5%AZM@GP)with reduced start-up time period,comparatively higher voltage output,more readable electrical signal and increased inhibition rate(30%-65%higher than control sensor with GP electrode)when exposing to toxic formaldehyde.This may be attributed to the fact that AZM inhibited the growth of non-EAM without much influence on the physiologic or metabolism activities of EAM under proper dosage.Further investigation of the biofilm morphology and microbial community analysis suggested that the biofilm formation was optimized with reduced thickness and enriched Geobacter with 0.5%AZM@GP dosage.This novel electrode is easily fabricated and equipped,and therefore would be a promising way to facilitate the practical application of EAB-sensors.展开更多
A novel amperometric biosensor for the detection of hydrogen peroxide is described. The biosensor was constructed by electrodepositing HRP/PPy membrane on the surface of ferrocenecarboxylic acid mediated sol-gel deriv...A novel amperometric biosensor for the detection of hydrogen peroxide is described. The biosensor was constructed by electrodepositing HRP/PPy membrane on the surface of ferrocenecarboxylic acid mediated sol-gel derived composite carbon electrode. The biosensor gives response to hydrogen peroxide in a few seconds with detection limit of 5×10-7 mol·L-1 (based on signal : noise=3). Linear range is up to 0.2 mmol·L-1.展开更多
This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets(micro-HC/nano-MnO2) composite prepared by an in situ self-limiting deposition method under hydroth...This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets(micro-HC/nano-MnO2) composite prepared by an in situ self-limiting deposition method under hydrothermal condition. The results of scanning electron microscopy reveal that MnO2 nanosheets homogeneously grow onto the surface of micro-HC to form a loose-packed microstructure. The quantity of MnO2 required in the electrode layer has thereby been reduced significantly, and higher specific capacitances have been achieved. The micro-HC/nano-MnO2 electrode presents a high capacitance of 239.0 F g-1 at a current density of 5 m A cm-2, which is a strong promise for high-rate electrochemical capacitive energy storage applications.展开更多
Lithium-ion batteries suffer from mechano–electrochemical coupling problems that directly determine the battery life. In this paper, we investigate the electrode electrochemical performance under stress conditions, w...Lithium-ion batteries suffer from mechano–electrochemical coupling problems that directly determine the battery life. In this paper, we investigate the electrode electrochemical performance under stress conditions, where seven tensile/compressive stresses are designed and loaded on electrodes, thereby decoupling mechanics and electrochemistry through incremental stress loads. Four types of multi-group electrochemical tests under tensile/compressive stress loading and normal package loading are performed to quantitatively characterize the effects of tensile stress and compressive stress on cycle performance and the kinetic performance of a silicon composite electrode. Experiments show that a tensile stress improves the electrochemical performance of a silicon composite electrode, exhibiting increased specific capacity and capacity retention rate, reduced energy dissipation rate and impedances, enhanced reactivity, accelerated ion/electron migration and diffusion, and reduced polarization. Contrarily, a compressive stress has the opposite effect, inhibiting the electrochemical performance. The stress effect is nonlinear, and a more obvious suppression via compressive stress is observed than an enhancement via tensile stress. For example, a tensile stress of 675 k Pa increases diffusion coefficient by 32.5%, while a compressive stress reduces it by 35%. Based on the experimental results, the stress regulation mechanism is analyzed. Tensile stress loads increase the pores of the electrode material microstructure, providing more deformation spaces and ion/electron transport channels. This relieves contact compressive stress, strengthens diffusion/reaction, and reduces the degree of damage and energy dissipation. Thus, the essence of stress enhancement is that it improves and optimizes diffusion, reaction and stress in the microstructure of electrode material as well as their interactions via physical morphology.展开更多
Metal-organic framework(MOF)and its derivatives have low-cost,controllable structure,and good catalytic performance,which are often used in the electrochemical field.In this work,SnO_(2)in situ modified graphite felt(...Metal-organic framework(MOF)and its derivatives have low-cost,controllable structure,and good catalytic performance,which are often used in the electrochemical field.In this work,SnO_(2)in situ modified graphite felt(SnO_(2)/GF)is prepared by hydrothermal method then simple thermal treatment using Sn-based MOF(Sn-MOF)as precursor.SnO_(2)is uniformly and firmly distributed on the GF surface rather than the common agglomeration and poor bonding of metal oxides on carbon-based electrodes,providing stable active centers for the VO^(2+)/VO_(2)^(+)and V^(2+)/V^(3+)redox reactions.At250 mA·cm^(-2),the energy efficiency of the battery with SnO_(2)/GF remains at 63.2%,while the blank one has failed.The former battery,at 100 mA·cm^(-2),has higher energy efficiency and good cycle stability(over 200 cycles).The battery performance of this study is better than that of most previous report in metal oxide-related work.This work obtains high-performance composite electrode by simple treatment of MOF,which provides a reference for the application of MOF in vanadium redox flow battery.展开更多
<span style="font-family:""><span style="font-family:Verdana;">Considering the great potential of composite electrode with carbon and transition metal oxides as a future ideal form...<span style="font-family:""><span style="font-family:Verdana;">Considering the great potential of composite electrode with carbon and transition metal oxides as a future ideal form of electrode for future energy storing system, many efforts have been devoted into such aspect of research. Sweet potato-derived carbon framework with nanosheet form of MnO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> anchored on it was carried out through the low-temperature solution grown technique, which is simple, low-cost, and applicable for large-scale commercial production. Such form of composite electrode can facilitate the inner transportation of electrons and ions, and offer high specific capacitance (309 F/g at 0.5 A/g) with comparable discharging rate capability (94 F/g at 20 A/g), which reasonably can be regarded as a superior form of composite electrode.展开更多
With the rapid emergence of wearable devices, flexible lithium-ion batteries(LIBs) are much more needed than ever. Free-standing graphene-based composite paper electrodes with various active materials have appealed wi...With the rapid emergence of wearable devices, flexible lithium-ion batteries(LIBs) are much more needed than ever. Free-standing graphene-based composite paper electrodes with various active materials have appealed wide applications in flexible LIBs. However, due to the prone-to-restacking feature of graphene layers, a long cycle life at high current densities is rather difficult to be achieved. Herein, a unique threedimensional(3D) hierarchically porous NiO micro-flowers/graphene paper(fNiO/GP) electrode is successfully fabricated. The resulting fNiO/GP electrode shows superior long-term cycling stability at high rates(e.g., storage capacity of 359 mAh/g after 600 cycles at a high current density of 1 A/g). The facile 3D porous structure combines both the advantages of the graphene that is highly conductive and flexible to ensure rapid electrons/ions transfer and buffer the volume expansion of NiO during charge/discharge,and of the micro-sized NiO flowers that induces hierarchical between-layer pores ranging from nanomicro meters to promote the penetration of the electrolyte and prevent the re-stacking of graphene layers. Such structural design will inspire future manufacture of a wide range of active materials/graphene composite electrodes for high performance flexible LIBs.展开更多
Lithium ion batteries have achieved extensive applications in portable electronics and recently in electronic vehicles since its commercialization in 1990s.The vast applications of lithium ion batteries are not only d...Lithium ion batteries have achieved extensive applications in portable electronics and recently in electronic vehicles since its commercialization in 1990s.The vast applications of lithium ion batteries are not only derived from the innovation in electrochemistry based on emerging energy materials and chemical engineering science,but also the technological advances in the powder technologies for electrode processing and cell fabrication.Revealing the effects of powder technology on electrode microstructure evolution during electrode processing is with critical value to realize the superior electrochemical performance.This review presents the progress in understanding the basic principles of the materials processing technologies for electrodes in lithium ion batteries.The impacts of slurry mixing and coating,electrode drying,and calendering on the electrode characteristics and electrochemical performance are comprehensively analyzed.Conclusion and outlook are drawn to shed fresh lights on the further development of efficient lithium ion batteries by advancing powder technologies and related advanced energy materials.展开更多
Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization.Dual form...Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization.Dual forms of high-crystalline nanosheet-like Ni(OH)_(2) severally distribute within mesopores or over the outer surface of 3DOMC particles depending on the loading amount(3%^(−1)5%)of Ni(OH)_(2).Benefitted from the highly hybrid combination and efficient electrolyte diffusion,the obtained Ni(OH)_(2)/carbon nanocomposites exhibit an excellent electrochemical performance,and the optimal sample of 6%_Ni(OH)_(2)/3DOMC with confined extrasmall Ni(OH)_(2) nanosheets as dominant shows the highest specific capacitance of 552.5F.g^(−1) at 1.0A⋅g^(−1),which is 330%higher than the contrast sample by using actived carbon as the support.Furthermore,the assembled hybrid supercapacitor by using 6%_Ni(OH)_(2)/3DOMC and 3DOMC as positive and negative electrodes displays an energy density of 11.7 Wh.kg^(−1) at 288.1 W.kg^(−1) and a superior charge/discharge stability.It is expected that the flexible component,well-defined structure,and superior electrochemical performance could promote a great application potential of Ni(OH)_(2)/3DOMC nanocomposites as supercapacitor electrodes and in other energy storage devices.展开更多
Efficiently harvesting low-grade heat is crucial for sustainable energy management. Thermocells(TECs), inducing heat-toelectricity conversion via the thermogalvanic effect, have thus drawn tremendous attention in rece...Efficiently harvesting low-grade heat is crucial for sustainable energy management. Thermocells(TECs), inducing heat-toelectricity conversion via the thermogalvanic effect, have thus drawn tremendous attention in recent years. This study introduces a self-assembly approach for fabricating aerogel sheet electrodes(ASEs) tailored for TECs. The crafted ASEs retain a remarkable porous architecture with approximately 95% porosity, even with their slimmed-down thickness. Results reveal that the electrode composition has minimal influence on the thermopower of TECs. Notably, the porous ASE with tunned composition demonstrates an optimal effective surface area for the thermogalvanic effect, resulting in enhanced output current density. This balances the desirable traits of electrode compactness with abundant redox active sites, positioning it favorably against conventional bulky electrode designs. The TECs utilizing the optimized ASE achieve a peak output power of 22.10 μW cm^(-2)under a temperature difference of 30 K. Furthermore, a tubular TEC device is readily assembled and specially designed for harvesting heat energy from hot fluids. These findings underscore the potential of composite electrodes in the realm of low-grade heat harvest, paving the way for broader applications in sustainable energy solutions.展开更多
Lithium(Li)metal is the most promising electrode for next-gene ration rechargeable batteries.In order to push the commercialization of the lithium metal batteries,a kind of nitrogen(N)-doped composite graphene(NCG)ado...Lithium(Li)metal is the most promising electrode for next-gene ration rechargeable batteries.In order to push the commercialization of the lithium metal batteries,a kind of nitrogen(N)-doped composite graphene(NCG)adopted as the Li plating host was prepared to regulate Li metal nucleation and suppress dendrite growth.Furthermore,a new kind of sandwich-type composite lithium metal(STCL)electrode was developed to improve its application.The STCL electrode can be used as convenient as a piece of Li foil but no dendrite growth.In a symmetric battery,the STCL electrode cycled for more than 4500 h with the overpotential of less than 40 mV.And due to the creative design,the STCL promises the Li-S battery with a prolonged cycling lifespan.展开更多
Smart energy storage has revolutionized portable electronics and electrical vehicles.The current smart energy storage devices have penetrated into flexible electronic markets at an unprecedented rate.Flexible batterie...Smart energy storage has revolutionized portable electronics and electrical vehicles.The current smart energy storage devices have penetrated into flexible electronic markets at an unprecedented rate.Flexible batteries are key power sources to enable vast flexible devices,which put forward additional requirements,such as bendable,twistable,stretchable,and ultrathin,to adapt mechanical deformation under the working conditions.This review summarizes the recent advances in construction and configuration of flexible batteries and discusses the general metrics to benchmark various flexible batteries with different materials and chemistries.Moreover,we present advanced prototype flexible batteries developed by some companies to afford general envision of the technological status.Lastly,the critical points are summarized in the development of flexible batteries and remaining challenges are also presented for the future design of flexible batteries in practical perspectives.展开更多
Alloy anode with good reversibility of lithium plating/stripping and long cycling stability is considered as promising anode materials.Here,Cu-Sn alloy is used as the substrate for Li deposition to induce the most den...Alloy anode with good reversibility of lithium plating/stripping and long cycling stability is considered as promising anode materials.Here,Cu-Sn alloy is used as the substrate for Li deposition to induce the most densely packed arrangement of Li atoms,thus presenting high lithiophilicity and improving Li plating behaviors.The LiFePO4-based full cell with the asprepared dendrite-free Li metal anode retained at 85 mAh g-1 with a high coulombic efficiency of 99.5% after 300 cycles,presenting a capacity retention of 79.4%.This strategy provides a new perspective to structure dendrite-free Li anode for the next-generation high-energy density batteries.展开更多
硅被认为是下一代锂离子电池极具潜力的负极材料.纳米硅的使用缓解了其在锂化时因体积变化引起的颗粒粉碎化.然而,团聚的硅颗粒间的相互挤压仍然会引起硅负极的迅速失效.为此,我们以弹性的石墨烯空心球为媒介在硅粒子之间引入机械缓冲空...硅被认为是下一代锂离子电池极具潜力的负极材料.纳米硅的使用缓解了其在锂化时因体积变化引起的颗粒粉碎化.然而,团聚的硅颗粒间的相互挤压仍然会引起硅负极的迅速失效.为此,我们以弹性的石墨烯空心球为媒介在硅粒子之间引入机械缓冲空间,来灵活缓冲硅的体积变化,保持电极结构的稳定性.在锂化过程中,硅体积膨胀产生的应力通过压缩石墨烯空心球的内部空心得到了机械式的缓冲.除此之外,石墨烯空心球还减少了硅颗粒的局部团聚,有效地提高了整体电导率.基于这些优势,所设计的Si/GS电极在0.8 A g^(-1)的电流密度下循环200圈后性能仍维持在1200 mA hg^(-1)以上;在4 A g^(-1)的电流密度下,200次循环后仍可达到1025 mA h g^(-1).展开更多
基金supported by National Natural Science Foundation of China(No.21872080)National Key Research and Development Program of China(2022YFB3803304)+2 种基金supported by Tsinghua University Initiative Scientific Research Program(20221080065,20223080044)The State Key Laboratory of Power System and Generation Equipment(Nos.SKLD21Z03 and SKLD20M03)the Chinese Thousand Talents Program for Young Professionals.
文摘Perovskite solar cells(PSCs)have become the represent-atives of next generation of photovoltaics;nevertheless,their stability is insufficient for large scale deployment,particularly the reverse bias stability.Here,we propose a transparent conducting oxide(TCO)and low-cost metal composite electrode to improve the stability of PSCs without sacrificing the efficiency.The TCO can block ion migrations and chemical reactions between the metal and perovskite,while the metal greatly enhances the conductivity of the composite electrode.As a result,composite electrode-PSCs achieved a power conversion efficiency(PCE)of 23.7%(certified 23.2%)and exhibited excellent stability,maintaining 95%of the initial PCE when applying a reverse bias of 4.0 V for 60 s and over 92%of the initial PCE after 1000 h continuous light soaking.This composite electrode strategy can be extended to different combinations of TCOs and metals.It opens a new avenue for improving the stability of PSCs.
基金financially supported by the National Natural Science Foundation of China(No.51874222).
文摘Composite electrodes prepared by cation exchange resins and activated carbon(AC)were used to adsorb Ⅴ(Ⅳ)in capacitive deionization(CDI).The electrode made of middle resin size(D860/AC M)had the largest specific surface area and mesoporous content than two other composite electrodes.Electrochemical analysis showed that D860/AC M presents higher specific capacitance and electrical double layer capacitor than the others,and significantly lower internal diffusion impedance.Thus,D860/AC M exhibits the highest adsorption capacity and rate of Ⅴ(Ⅳ)among three electrodes.The intra-particle diffusion model fits well in the initial adsorption stage,while the liquid film diffusion model is more suitable for fitting at the later stage.The pseudo-second-order kinetic model is suited for the entire adsorption process.The adsorption of Ⅴ(Ⅳ)on the composite electrode follows that of the Freundlich isotherm.Thermodynamic analysis indicates that the adsorption of Ⅴ(Ⅳ)is an exothermic process with entropy reduction,and the electric field force plays a dominant role in the CDI process.This work aims to improve our understanding of the ion adsorption behaviors and mechanisms on the composite electrodes in CDI.
基金National Natural Science Foundation of China,Grant/Award Numbers:21835003,21422402,21674050,62005126National Key Basic Research Program of China,Grant/Award Numbers:2014CB648300,2017YFB0404501+7 种基金Natural Science Foundation of Jiangsu Province,Grant/Award Numbers:BE2019120,BK20140060Program for Jiangsu Specially-Appointed Professor,Grant/Award Number:RK030STP15001Six Talent Peaks Project of Jiangsu Province,Grant/Award Number:TD-XCL-009333 Project of Jiangsu Province,Grant/Award Number:BRA2017402Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of ChinaExcellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions,Grant/Award Number:TJ217038NUPT Scientific Foundation,Grant/Award Number:NY220152Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Stretchable organic light-emitting diodes(OLEDs)are important components for flexible/wearable electronics.However,the efficiency of the existing stretchable OLEDs is still much lower as compared with their rigid counterparts,one of the main reasons being the lack of ideal flexible transparent electrodes.Herein,we propose and develop a printed embedded metal composite electrode(PEMCE)strategy that enables the fabrication of ultra-thin,highly flexible transparent electrodes with robust mechanical properties.With the flexible transparent electrodes serves as the anodes,flexible/stretchable white OLEDs have been successfully constructed,achieving a current efficiency of up to 77.4 cd A^(-1)and a maximum luminance of 34787 cd m^(-2).The current efficiency of the resulting stretchable OLEDs is the highest ever reported for flexible/stretchable white OLEDs,which is about 1.2 times higher than that of the reference rigid devices based on ITO/glass electrodes.The excellent optoelectronic properties of the printed embedded transparent electrodes and the light extraction effect of the Ag-mesh account for the significant increase in current efficiency.Remarkably,the electroluminescence performance still retains~83%of the original luminance even after bending the device 2000 cycles at a radii of~0.5 mm.More importantly,the device can withstand tensile strains of up to~100%,and even mechanical deformation of 90%tensile strain does not result in a significant loss of electroluminescence performance with current efficiency and luminance maintained at over 85%.The results confirm that the PEMCE strategy is effective for constructing ultra-flexible transparent electrodes,showing great promise for use in a variety of flexible/stretchable electronics.
基金supported by the strategic grant POSDRU/88/1.5/S/50783POSDRU/21/1.5/G/13798+1 种基金POSDRU/89/1.5/S/57649 co-financed by the European Social Fund - Investing in People,within the Sectoral Operational Programme Human Resources Development 2007-2013partially by the PN II-RU-PD129/2010 and PN II Ideas 165/2011
文摘This work describes the electrochemical behaviour of ibuprofen on two types of multi-walled carbon nanotubes based composite electrodes,i.e.,multi-walled carbon nanotubes-epoxy(MWCNT) and silver-modified zeolite-multi-walled carbon nanotubes-epoxy(AgZMWCNT) composites electrodes.The composite electrodes were obtained using two-roll mill procedure.SEM images of surfaces of the composites revealed a homogeneous distribution of the composite components within the epoxy matrix.AgZMWCNT composite electrode exhibited the better electrical conductivity and larger electroactive surface area.The electrochemical determination of ibuprofen(IBP) was achieved using AgZMWCNT by cyclic voltammetry,differential-pulsed voltammetry,square-wave voltammetry and chronoamperometry.The IBP degradation occurred on both composite electrodes under controlled electrolysis at 1.2 and 1.75 V vs.Ag/AgCl,and IBP concentration was determined comparatively by differential-pulsed voltammetry,under optimized conditions using AgZMWCNT electrode and UV-Vis spectrophotometry methods to determine the IBP degradation performance for each electrode.AgZMWCNT electrode exhibited a dual character allowing a double application in IBP degradation process and its control.
文摘1 Results The phenomena that affect the membranes could be found in the electrodes when they operate at medium temperature,due to the utilisation of Nafion as an ionomer in the catalytic layer.An approach to improve the mechanical properties of the ionomer in the catalytic layer was used: different inorganic compounds (zeolite,titania and zirconia),having different chemical-physical properties,were selected as inorganic fillers due to their water retention capacity and to act as mechanical reinforce by ...
基金supported by the National Natural Science Foundation of China (Grant Nos.12072183,11872236 and 12172205)the Key Research Project of Zhejiang Laboratory (No.2021PE0AC02).
文摘The variation of the effective modulus of silicon composite electrodes,which is a fundamental feature to analyze the coupled mechanical–electrochemical behavior of Si-based electrodes in high-capacity lithium-ion batteries,remains qualitatively controversial.To clarify the contradictory experimental results,numerical modeling of a representative volume element with silicon particles,carbon-binder domains(CBDs),and pores has been performed for the lithiation process.The key parameters for modulus variation were identified and evaluated.A mesostructure change is proposed to be a crucial mechanism that affects the modulus variation,and silicon softening is another key mechanism.Silicon softening and the decreasing CBD volume fraction collectively result in a decrease in the effective modulus of the composite,whereas an increase in the silicon volume fraction along with a decrease in porosity has the opposite effect.The findings of this work provide an in-depth and fundamental understanding of the mechanical properties of silicon composite electrodes.
基金This work was supported by the National Natural Science Foundation of China(Grant No.52125001).
文摘Extensive research has been carried out for improved sensitivity of electroactive biofilm-based sensor(EAB-sensor),which is recognized as a useful tool in water quality early-warning.Antibiotic that is employed widely to treat infection has been proved feasible in this study to regulate the EAB and to increase the EAB-biosensor’s sensitivity.A novel composite electrode was prepared using azithromycin(AZM)and graphite powder(GP),namely AZM@GP electrode,and was employed as the anode in EAB-biosensor.Different dosages of AZM,i.e.,2 mg,4 mg,and 8 mg,referred to as 0.25%,0.5%and 1%AZM@GP were under examination.Results showed that EAB-biosensor was greatly benefited from appropriate dosage of AZM(0.5%AZM@GP)with reduced start-up time period,comparatively higher voltage output,more readable electrical signal and increased inhibition rate(30%-65%higher than control sensor with GP electrode)when exposing to toxic formaldehyde.This may be attributed to the fact that AZM inhibited the growth of non-EAM without much influence on the physiologic or metabolism activities of EAM under proper dosage.Further investigation of the biofilm morphology and microbial community analysis suggested that the biofilm formation was optimized with reduced thickness and enriched Geobacter with 0.5%AZM@GP dosage.This novel electrode is easily fabricated and equipped,and therefore would be a promising way to facilitate the practical application of EAB-sensors.
文摘A novel amperometric biosensor for the detection of hydrogen peroxide is described. The biosensor was constructed by electrodepositing HRP/PPy membrane on the surface of ferrocenecarboxylic acid mediated sol-gel derived composite carbon electrode. The biosensor gives response to hydrogen peroxide in a few seconds with detection limit of 5×10-7 mol·L-1 (based on signal : noise=3). Linear range is up to 0.2 mmol·L-1.
基金supported by the National Natural Science Foundation of China (51203071, 51363014 and 51362018)China Postdoctoral Science Foundation (2014M552509)+1 种基金the Key Project of Chinese Ministry of Education (212183)the Natural Science Funds for Distinguished Young Scholars of Gansu Province (1111RJDA012)
文摘This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets(micro-HC/nano-MnO2) composite prepared by an in situ self-limiting deposition method under hydrothermal condition. The results of scanning electron microscopy reveal that MnO2 nanosheets homogeneously grow onto the surface of micro-HC to form a loose-packed microstructure. The quantity of MnO2 required in the electrode layer has thereby been reduced significantly, and higher specific capacitances have been achieved. The micro-HC/nano-MnO2 electrode presents a high capacitance of 239.0 F g-1 at a current density of 5 m A cm-2, which is a strong promise for high-rate electrochemical capacitive energy storage applications.
基金Project supported by the Major Program of the National Natural Science Foundation of China(Grant No.11890680)the National Natural Science Foundation of China(Grant No.12022205)。
文摘Lithium-ion batteries suffer from mechano–electrochemical coupling problems that directly determine the battery life. In this paper, we investigate the electrode electrochemical performance under stress conditions, where seven tensile/compressive stresses are designed and loaded on electrodes, thereby decoupling mechanics and electrochemistry through incremental stress loads. Four types of multi-group electrochemical tests under tensile/compressive stress loading and normal package loading are performed to quantitatively characterize the effects of tensile stress and compressive stress on cycle performance and the kinetic performance of a silicon composite electrode. Experiments show that a tensile stress improves the electrochemical performance of a silicon composite electrode, exhibiting increased specific capacity and capacity retention rate, reduced energy dissipation rate and impedances, enhanced reactivity, accelerated ion/electron migration and diffusion, and reduced polarization. Contrarily, a compressive stress has the opposite effect, inhibiting the electrochemical performance. The stress effect is nonlinear, and a more obvious suppression via compressive stress is observed than an enhancement via tensile stress. For example, a tensile stress of 675 k Pa increases diffusion coefficient by 32.5%, while a compressive stress reduces it by 35%. Based on the experimental results, the stress regulation mechanism is analyzed. Tensile stress loads increase the pores of the electrode material microstructure, providing more deformation spaces and ion/electron transport channels. This relieves contact compressive stress, strengthens diffusion/reaction, and reduces the degree of damage and energy dissipation. Thus, the essence of stress enhancement is that it improves and optimizes diffusion, reaction and stress in the microstructure of electrode material as well as their interactions via physical morphology.
基金the National Natural Science Foundation of China(Nos.51872090 and 51772097)Hebei Natural Science Fund for Distinguished Young Scholar(No.E2019209433)+1 种基金the Youth Talent Program of Hebei Provincial Education Department(No.BJ2018020)the Natural Science Foundation of Hebei Province(No.E2020209151)。
文摘Metal-organic framework(MOF)and its derivatives have low-cost,controllable structure,and good catalytic performance,which are often used in the electrochemical field.In this work,SnO_(2)in situ modified graphite felt(SnO_(2)/GF)is prepared by hydrothermal method then simple thermal treatment using Sn-based MOF(Sn-MOF)as precursor.SnO_(2)is uniformly and firmly distributed on the GF surface rather than the common agglomeration and poor bonding of metal oxides on carbon-based electrodes,providing stable active centers for the VO^(2+)/VO_(2)^(+)and V^(2+)/V^(3+)redox reactions.At250 mA·cm^(-2),the energy efficiency of the battery with SnO_(2)/GF remains at 63.2%,while the blank one has failed.The former battery,at 100 mA·cm^(-2),has higher energy efficiency and good cycle stability(over 200 cycles).The battery performance of this study is better than that of most previous report in metal oxide-related work.This work obtains high-performance composite electrode by simple treatment of MOF,which provides a reference for the application of MOF in vanadium redox flow battery.
文摘<span style="font-family:""><span style="font-family:Verdana;">Considering the great potential of composite electrode with carbon and transition metal oxides as a future ideal form of electrode for future energy storing system, many efforts have been devoted into such aspect of research. Sweet potato-derived carbon framework with nanosheet form of MnO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> anchored on it was carried out through the low-temperature solution grown technique, which is simple, low-cost, and applicable for large-scale commercial production. Such form of composite electrode can facilitate the inner transportation of electrons and ions, and offer high specific capacitance (309 F/g at 0.5 A/g) with comparable discharging rate capability (94 F/g at 20 A/g), which reasonably can be regarded as a superior form of composite electrode.
基金financially supported by the National Key R&D Program of China (No.2017YFE0111500)the National Natural Science Foundation of China (No.51673123 and 51222305)Sichuan Province Science and Technology Project (No.2016JQ0049)。
文摘With the rapid emergence of wearable devices, flexible lithium-ion batteries(LIBs) are much more needed than ever. Free-standing graphene-based composite paper electrodes with various active materials have appealed wide applications in flexible LIBs. However, due to the prone-to-restacking feature of graphene layers, a long cycle life at high current densities is rather difficult to be achieved. Herein, a unique threedimensional(3D) hierarchically porous NiO micro-flowers/graphene paper(fNiO/GP) electrode is successfully fabricated. The resulting fNiO/GP electrode shows superior long-term cycling stability at high rates(e.g., storage capacity of 359 mAh/g after 600 cycles at a high current density of 1 A/g). The facile 3D porous structure combines both the advantages of the graphene that is highly conductive and flexible to ensure rapid electrons/ions transfer and buffer the volume expansion of NiO during charge/discharge,and of the micro-sized NiO flowers that induces hierarchical between-layer pores ranging from nanomicro meters to promote the penetration of the electrolyte and prevent the re-stacking of graphene layers. Such structural design will inspire future manufacture of a wide range of active materials/graphene composite electrodes for high performance flexible LIBs.
基金This work was supported by National Natural Science Foundation of China(Grant Nos.21805161,21808121,and 21825501)National Key Research and Development Program(Grant No.2016YFA0202500)+1 种基金China Post-Doctoral Science Foundation(Grant Nos.2020M670155 and 2020T130054)the Tsinghua University Initiative Scientific Research Program.
文摘Lithium ion batteries have achieved extensive applications in portable electronics and recently in electronic vehicles since its commercialization in 1990s.The vast applications of lithium ion batteries are not only derived from the innovation in electrochemistry based on emerging energy materials and chemical engineering science,but also the technological advances in the powder technologies for electrode processing and cell fabrication.Revealing the effects of powder technology on electrode microstructure evolution during electrode processing is with critical value to realize the superior electrochemical performance.This review presents the progress in understanding the basic principles of the materials processing technologies for electrodes in lithium ion batteries.The impacts of slurry mixing and coating,electrode drying,and calendering on the electrode characteristics and electrochemical performance are comprehensively analyzed.Conclusion and outlook are drawn to shed fresh lights on the further development of efficient lithium ion batteries by advancing powder technologies and related advanced energy materials.
基金the National Natural Science Foundation of China(Nos.21978238,21878248,and 21978055)Natural Science Foundation of Shaanxi Provincial Department of Education(No.21JY041).
文摘Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization.Dual forms of high-crystalline nanosheet-like Ni(OH)_(2) severally distribute within mesopores or over the outer surface of 3DOMC particles depending on the loading amount(3%^(−1)5%)of Ni(OH)_(2).Benefitted from the highly hybrid combination and efficient electrolyte diffusion,the obtained Ni(OH)_(2)/carbon nanocomposites exhibit an excellent electrochemical performance,and the optimal sample of 6%_Ni(OH)_(2)/3DOMC with confined extrasmall Ni(OH)_(2) nanosheets as dominant shows the highest specific capacitance of 552.5F.g^(−1) at 1.0A⋅g^(−1),which is 330%higher than the contrast sample by using actived carbon as the support.Furthermore,the assembled hybrid supercapacitor by using 6%_Ni(OH)_(2)/3DOMC and 3DOMC as positive and negative electrodes displays an energy density of 11.7 Wh.kg^(−1) at 288.1 W.kg^(−1) and a superior charge/discharge stability.It is expected that the flexible component,well-defined structure,and superior electrochemical performance could promote a great application potential of Ni(OH)_(2)/3DOMC nanocomposites as supercapacitor electrodes and in other energy storage devices.
基金supported by the National Natural Science Foundation of China (52103089, 52242305)Guangdong Basic and Applied Basic Research Foundation (2023A1515012120)+1 种基金Shenzhen Science and Technology Program (JCYJ20220531100815035, RCBS202210-08093126069)the Opening Project of State Key Laboratory of Polymer Materials Engineering (sklpme2022-4-08)。
文摘Efficiently harvesting low-grade heat is crucial for sustainable energy management. Thermocells(TECs), inducing heat-toelectricity conversion via the thermogalvanic effect, have thus drawn tremendous attention in recent years. This study introduces a self-assembly approach for fabricating aerogel sheet electrodes(ASEs) tailored for TECs. The crafted ASEs retain a remarkable porous architecture with approximately 95% porosity, even with their slimmed-down thickness. Results reveal that the electrode composition has minimal influence on the thermopower of TECs. Notably, the porous ASE with tunned composition demonstrates an optimal effective surface area for the thermogalvanic effect, resulting in enhanced output current density. This balances the desirable traits of electrode compactness with abundant redox active sites, positioning it favorably against conventional bulky electrode designs. The TECs utilizing the optimized ASE achieve a peak output power of 22.10 μW cm^(-2)under a temperature difference of 30 K. Furthermore, a tubular TEC device is readily assembled and specially designed for harvesting heat energy from hot fluids. These findings underscore the potential of composite electrodes in the realm of low-grade heat harvest, paving the way for broader applications in sustainable energy solutions.
基金financially supported by the Beijing Municipal Science and Technology Project(Nos.Z171100000917021 and Z181100004518003)。
文摘Lithium(Li)metal is the most promising electrode for next-gene ration rechargeable batteries.In order to push the commercialization of the lithium metal batteries,a kind of nitrogen(N)-doped composite graphene(NCG)adopted as the Li plating host was prepared to regulate Li metal nucleation and suppress dendrite growth.Furthermore,a new kind of sandwich-type composite lithium metal(STCL)electrode was developed to improve its application.The STCL electrode can be used as convenient as a piece of Li foil but no dendrite growth.In a symmetric battery,the STCL electrode cycled for more than 4500 h with the overpotential of less than 40 mV.And due to the creative design,the STCL promises the Li-S battery with a prolonged cycling lifespan.
基金National Natural Science Foundation of China,Grant/Award Numbers:21805162,21825501,and U1801257。
文摘Smart energy storage has revolutionized portable electronics and electrical vehicles.The current smart energy storage devices have penetrated into flexible electronic markets at an unprecedented rate.Flexible batteries are key power sources to enable vast flexible devices,which put forward additional requirements,such as bendable,twistable,stretchable,and ultrathin,to adapt mechanical deformation under the working conditions.This review summarizes the recent advances in construction and configuration of flexible batteries and discusses the general metrics to benchmark various flexible batteries with different materials and chemistries.Moreover,we present advanced prototype flexible batteries developed by some companies to afford general envision of the technological status.Lastly,the critical points are summarized in the development of flexible batteries and remaining challenges are also presented for the future design of flexible batteries in practical perspectives.
基金financially supported by the National Natural Science Foundation of China(No.21673051)the Department of Science and Technology of Guangdong Province,China(No.2019A050510043)。
文摘Alloy anode with good reversibility of lithium plating/stripping and long cycling stability is considered as promising anode materials.Here,Cu-Sn alloy is used as the substrate for Li deposition to induce the most densely packed arrangement of Li atoms,thus presenting high lithiophilicity and improving Li plating behaviors.The LiFePO4-based full cell with the asprepared dendrite-free Li metal anode retained at 85 mAh g-1 with a high coulombic efficiency of 99.5% after 300 cycles,presenting a capacity retention of 79.4%.This strategy provides a new perspective to structure dendrite-free Li anode for the next-generation high-energy density batteries.
基金supported by the National Natural Science Foundation of China(52071225,52172240,51702225 and 51672181)Czech Republic through the ERDF“Institute of Environmental TechnologyExcellent Research”grant(CZ.02.1.01/0.0/0.0/16_019/0000853)+3 种基金the SinoGerman Research Institute for their support(Project GZ 1400)the Fundamental Research Funds for the Central Universities(20720200075)Beijing Municipal Science and Technology Commission(Z161100002116020)the Natural Science Foundation of Jiangsu Province(BK20170336)。
文摘硅被认为是下一代锂离子电池极具潜力的负极材料.纳米硅的使用缓解了其在锂化时因体积变化引起的颗粒粉碎化.然而,团聚的硅颗粒间的相互挤压仍然会引起硅负极的迅速失效.为此,我们以弹性的石墨烯空心球为媒介在硅粒子之间引入机械缓冲空间,来灵活缓冲硅的体积变化,保持电极结构的稳定性.在锂化过程中,硅体积膨胀产生的应力通过压缩石墨烯空心球的内部空心得到了机械式的缓冲.除此之外,石墨烯空心球还减少了硅颗粒的局部团聚,有效地提高了整体电导率.基于这些优势,所设计的Si/GS电极在0.8 A g^(-1)的电流密度下循环200圈后性能仍维持在1200 mA hg^(-1)以上;在4 A g^(-1)的电流密度下,200次循环后仍可达到1025 mA h g^(-1).