Due to the abundant sodium reserves and high safety,sodium ion batteries(SIBs)are foreseen a promising future.While,hard carbon materials are very suitable for the anode of SIBs owing to their structure and cost advan...Due to the abundant sodium reserves and high safety,sodium ion batteries(SIBs)are foreseen a promising future.While,hard carbon materials are very suitable for the anode of SIBs owing to their structure and cost advantages.However,the unsatisfactory initial coulombic efficiency(ICE)is one of the crucial blemishes of hard carbon materials and the slow sodium storage kinetics also hinders their wide application.Herein,with spherical nano SiO_(2)as pore-forming agent,gelatin and polytetrafluoroethylene as carbon sources,a multi-porous carbon(MPC)material can be easily obtained via a co-pyrolysis method,by which carbonization and template removal can be achieved synchronously without the assistance of strong acids or strong bases.As a result,the MPC anode exhibited remarkable ICE of 83%and a high rate capability(208 m Ah/g at 5 A/g)when used in sodium-ion half cells.Additionally,coupling with Na3V2(PO4)3as the cathode to assemble full cells,the as-fabricated MPC//NVP full cell delivered a good rate capability(146 m Ah/g at 5 A/g)as well,implying a good application prospect the MPC anode has.展开更多
Developing excellent pseudocapacitive electrodes with long cycle,high areal capacity and large rate has been challenged.3 D printing is an additive manufacture technique that has been explored to construct microelectr...Developing excellent pseudocapacitive electrodes with long cycle,high areal capacity and large rate has been challenged.3 D printing is an additive manufacture technique that has been explored to construct microelectrodes of arbitrary geometries for high-energy–density supercapacitors.In comparison with conventional electrodes with uncontrollable geometries and architectures,3 D-printed electrodes possess unique advantage in geometrical shape,mechanical properties,surface area,especially in ion transport and charge transfer.Thus,a desirable 3 D electrode with ordered porous structures can be elaborately designed by 3 D printing technology for improving electrochemical capacitance and rate capability.In this work,a designed,monolithic and ordered multi-porous 3 D Cu conductive skeleton was manufactured through 3 D direct ink writing technique and coated with Cu O nanosheet arrays by an in situ electro-oxidation treatment.Benefiting from the highly ordered multiporous nature,the 3 D-structured skeleton can eff ectively enlarge the surface area,enhance the penetration of electrolyte and facilitate fast electron and ion transport.As a result,the 3 D-printed Cu deposited with electro-oxidation-generated CuO(3 DP Cu@Cu O)electrodes demonstrates an ultrahigh areal capacitance of 1.690 F cm^(-2)(38.79 F cm^(-3))at a large current density of 30 m A cm^(-2)(688.59 m A cm^(-3)),excellent lifespan of 88.20%capacitance retention after 10,000 cycles at 30 m A cm^(-2) and superior rate capability(94.31%retention,2-30 m A cm^(-2)).This design concept of 3 D printing multi-porous current collector with hierarchical active materials provides a novel way to build high-performance 3 D microelectrodes.展开更多
Dye wastewater containing heavy metal ions is a common industrial effluent with complex physicochemical properties. The treatment of metal-dye binary wastewater is difficult. In this work, a novel in-situ ferrite proc...Dye wastewater containing heavy metal ions is a common industrial effluent with complex physicochemical properties. The treatment of metal-dye binary wastewater is difficult. In this work, a novel in-situ ferrite process （IFP） was applied to treat Methylene Blue （MB）-Cu（II） binary wastewater, and the operational parameters were optimized for MB removal. Results showed that the optimum operating conditions were OH/M of 1.72, Cu2＋/Fe2＋ ratio of 1/2.5, reaction time of 90 min, aeration intensity of 320 mL/min, and reaction temperature of 40℃. Moreover, the presence of Ca2＋ and Mg2＋ moderately influenced the MB removal. Physical characterization results indicated that the precipitates yielded in IFP presented high surface area {232.50 m2/g） and a multi-porous structure. Based on the Langmuir model, the maximum adsorption capacity toward MB was 347.82 mg/g for the precipitates produced in IFP, which outperformed most other adsorbents. Furthermore, IFP rapidly sequestered MB with removal efficiency 5 to 10 times greater than that by general ferrite adsorption, which suggested a strong enhancement of MB removal by IFP. The MB removal process by IFP showed two different high removal stages, each with a corresponding removal mechanism. In the first brief stage （〈5 min）, the initial high MB removal （～95%） was achieved by predominantly electrostatic interactions. Then the sweep effect and encapsulation were dominant in the second longer stage.展开更多
The orientation of the dimple increases the flow distance in the dimple and produces fluid cumulative effect in the dimple length direction, which leads to obvious hydrodynamic effect as a result. In order to investig...The orientation of the dimple increases the flow distance in the dimple and produces fluid cumulative effect in the dimple length direction, which leads to obvious hydrodynamic effect as a result. In order to investigate the hydrodynamic effect of orientation dimples, a series of experiments was carried out on a ring-on-ring test. Multi-pored faces were tested with different dimple inclination angles and slender ratios. Film thickness and frictional torque were measured under different conditions of load and rotation speed. Experimental results showed that the orientation dimple could produce obvious dynamic effect by change of the flow direction and the increasing dimple orientation leads to increase of the load capability. The hydrodynamic effect strongly depends on dimple orientation parameters such as inclination angle and slender ratio. A larger load capability can be available by increasing dimple orientation and rotation speed. Experimental results agreed well with the theory that orientation micro-pores can significantly improve hydrodynamic performance of surfaces.展开更多
基金financially supported by the Start-up Funding of Jinan University(No.88016105)the Discipline Construction Outstanding Young Backbone Project(No.12819023)+3 种基金the Fundamental Research Funds for the Central Universities(No.21620317)the Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515110611 and 2021A1515010362)the Guangzhou Basic and Applied Basic Research Foundation(No.202102020995)supported by the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(No.2020B121201005)。
文摘Due to the abundant sodium reserves and high safety,sodium ion batteries(SIBs)are foreseen a promising future.While,hard carbon materials are very suitable for the anode of SIBs owing to their structure and cost advantages.However,the unsatisfactory initial coulombic efficiency(ICE)is one of the crucial blemishes of hard carbon materials and the slow sodium storage kinetics also hinders their wide application.Herein,with spherical nano SiO_(2)as pore-forming agent,gelatin and polytetrafluoroethylene as carbon sources,a multi-porous carbon(MPC)material can be easily obtained via a co-pyrolysis method,by which carbonization and template removal can be achieved synchronously without the assistance of strong acids or strong bases.As a result,the MPC anode exhibited remarkable ICE of 83%and a high rate capability(208 m Ah/g at 5 A/g)when used in sodium-ion half cells.Additionally,coupling with Na3V2(PO4)3as the cathode to assemble full cells,the as-fabricated MPC//NVP full cell delivered a good rate capability(146 m Ah/g at 5 A/g)as well,implying a good application prospect the MPC anode has.
基金financially supported by the National Natural Science Foundation of China(Nos.51771236,51901249 and U1904216)the Science Fund for Distinguished Young Scholars of Hunan Province(No.2018JJ1038)。
文摘Developing excellent pseudocapacitive electrodes with long cycle,high areal capacity and large rate has been challenged.3 D printing is an additive manufacture technique that has been explored to construct microelectrodes of arbitrary geometries for high-energy–density supercapacitors.In comparison with conventional electrodes with uncontrollable geometries and architectures,3 D-printed electrodes possess unique advantage in geometrical shape,mechanical properties,surface area,especially in ion transport and charge transfer.Thus,a desirable 3 D electrode with ordered porous structures can be elaborately designed by 3 D printing technology for improving electrochemical capacitance and rate capability.In this work,a designed,monolithic and ordered multi-porous 3 D Cu conductive skeleton was manufactured through 3 D direct ink writing technique and coated with Cu O nanosheet arrays by an in situ electro-oxidation treatment.Benefiting from the highly ordered multiporous nature,the 3 D-structured skeleton can eff ectively enlarge the surface area,enhance the penetration of electrolyte and facilitate fast electron and ion transport.As a result,the 3 D-printed Cu deposited with electro-oxidation-generated CuO(3 DP Cu@Cu O)electrodes demonstrates an ultrahigh areal capacitance of 1.690 F cm^(-2)(38.79 F cm^(-3))at a large current density of 30 m A cm^(-2)(688.59 m A cm^(-3)),excellent lifespan of 88.20%capacitance retention after 10,000 cycles at 30 m A cm^(-2) and superior rate capability(94.31%retention,2-30 m A cm^(-2)).This design concept of 3 D printing multi-porous current collector with hierarchical active materials provides a novel way to build high-performance 3 D microelectrodes.
基金supported by National Key Research and Development Program of China(No.2016YFA0203204)the National Natural Science Foundation of China(Nos.51478041 and 51678053)
文摘Dye wastewater containing heavy metal ions is a common industrial effluent with complex physicochemical properties. The treatment of metal-dye binary wastewater is difficult. In this work, a novel in-situ ferrite process （IFP） was applied to treat Methylene Blue （MB）-Cu（II） binary wastewater, and the operational parameters were optimized for MB removal. Results showed that the optimum operating conditions were OH/M of 1.72, Cu2＋/Fe2＋ ratio of 1/2.5, reaction time of 90 min, aeration intensity of 320 mL/min, and reaction temperature of 40℃. Moreover, the presence of Ca2＋ and Mg2＋ moderately influenced the MB removal. Physical characterization results indicated that the precipitates yielded in IFP presented high surface area {232.50 m2/g） and a multi-porous structure. Based on the Langmuir model, the maximum adsorption capacity toward MB was 347.82 mg/g for the precipitates produced in IFP, which outperformed most other adsorbents. Furthermore, IFP rapidly sequestered MB with removal efficiency 5 to 10 times greater than that by general ferrite adsorption, which suggested a strong enhancement of MB removal by IFP. The MB removal process by IFP showed two different high removal stages, each with a corresponding removal mechanism. In the first brief stage （〈5 min）, the initial high MB removal （～95%） was achieved by predominantly electrostatic interactions. Then the sweep effect and encapsulation were dominant in the second longer stage.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50805130, 50775206)the Zhejiang Nature Science Foundation of China (Grant Nos. Y1090620, R1090833)+1 种基金the Tribology Science Fund of State Key Laboratory of Tribology of China (Grant No. SKLTKF08B01)the Program of Young Leaders and Core Instructors of Disciplines in Science of Zhejiang University of Technology (Grant No. 102004829)
文摘The orientation of the dimple increases the flow distance in the dimple and produces fluid cumulative effect in the dimple length direction, which leads to obvious hydrodynamic effect as a result. In order to investigate the hydrodynamic effect of orientation dimples, a series of experiments was carried out on a ring-on-ring test. Multi-pored faces were tested with different dimple inclination angles and slender ratios. Film thickness and frictional torque were measured under different conditions of load and rotation speed. Experimental results showed that the orientation dimple could produce obvious dynamic effect by change of the flow direction and the increasing dimple orientation leads to increase of the load capability. The hydrodynamic effect strongly depends on dimple orientation parameters such as inclination angle and slender ratio. A larger load capability can be available by increasing dimple orientation and rotation speed. Experimental results agreed well with the theory that orientation micro-pores can significantly improve hydrodynamic performance of surfaces.
