Carbon materials with adjustable porosity,controllable het-eroatom doping and low-cost have been received considerable attention as supercapacitor electrodes.However,using carbon materials with abundant micropores,a h...Carbon materials with adjustable porosity,controllable het-eroatom doping and low-cost have been received considerable attention as supercapacitor electrodes.However,using carbon materials with abundant micropores,a high surface area and a high-dopant content for an aqueous su-percapacitor with a high energy output still remains a challenge.We report the easy synthesis of interconnected carbon spheres by a polymerization re-action between p-benzaldehyde and 2,6-diaminopyridine.The synthesis in-volves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output,which are attributed to the high ion-accessible area provided by the large number of micropores,high N/O contents and rapid ion diffusion channels in the porous structure.At a PMEC∶KOH mass ratio of 1∶1,the high electrolyte ion-adsorption area(2599.76 m^(2) g^(−1))and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity(303.2 F g^(−1)@0.5 A g^(−1))giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg^(−1)@250 W kg^(−1).This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.展开更多
For the purpose of improving the electrochemical cycle stability of the La-Mg-Ni based A2BT-type electrode alloys, both reducing Mg content and substituting La with Pr were adopted. The Lao.8-xPrxMg0.2Ni3.15Co0.2A10.1...For the purpose of improving the electrochemical cycle stability of the La-Mg-Ni based A2BT-type electrode alloys, both reducing Mg content and substituting La with Pr were adopted. The Lao.8-xPrxMg0.2Ni3.15Co0.2A10.1Si0.05 （x=0, 0.1, 0.2, 0.3, 0.4） electrode alloys were fabricated by casting and annealing. The investigation on the structures and electrochemical performances of the alloys was performed. The obtained results reveal that the as-cast and annealed alloys comprise two major phases, （La, Mg）2Ni7 phase with the hexagonal Ce2NiT-type structure and LaNi5 phase with the hexagonal CaCus-type structure, as well as a little residual LaNi3 phase. It is also found that the addition of Pr element observably affects the electrochemical hydrogen storage characteristics of the alloys, just as the discharge capacity and high rate discharge ability （HRD） first rise then fall with the growing of Pr content, and among all the alloys, the as-cast and annealed （x=0.3） alloys generate the largest discharge capacities of 360.8 and 386.5 mA.h/g, respectively. Additionally, the electrochemical cycle stability of all the alloys markedly grows with the increase of Pr content. The capacity retaining rate （S100） at the 100th charging and discharging cycle is enhanced from 64.98% to 77.55% for the as-cast alloy, and from 76.60% to 95.72% for the as-annealed alloy by rising Pr content from 0 to 0.4. Furthermore, the substitution of Pr for La results in first increase and then decrease in the hydrogen diffusion coefficient （D）, the limiting current density （IL） as well as the electrochemical impedance.展开更多
The La-Mg-Ni-based A2B7-type La0.5Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The influences of the additional silicon and the annealing treatment on the structure and elect...The La-Mg-Ni-based A2B7-type La0.5Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The influences of the additional silicon and the annealing treatment on the structure and electrochemical performances of the alloys were investigated systemically. Both of the analyses of XRD and SEM reveal that the as-cast and annealed alloys are of a multiphase structure, involving two main phases （La, Mg）2Ni7 and LaNi5 as well as one minor phase LaNi3. The addition of Si and annealing treatment bring on an evident change in the phase abundances and cell parameters of （La, Mg）2Ni7 and LaNi5 phase for the alloy without altering its phase structure. The phase abundances decrease from 74.3% （x=0） to 57.8% （x=0.2） for the （La, Mg）2Ni7 phase, and those of LaNi5 phase increase from 20.2% （x^0） to 37.3% （x=0.2）. As for the electrochemical measurements, adding Si and performing annealing treatment have engendered obvious impacts. The cycle stability of the alloys is improved dramatically, being enhanced from 80.3% to 93.7% for the as-annealed （950 ℃） alloys with Si content increasing from 0 to 0.2. However, the discharge capacity is reduced by adding Si, from 399.4 to 345.3 mA.h/g as the Si content increases from 0 to 0.2. Furthermore, such addition makes the electrochemical kinetic properties of the alloy electrodes first increase and then decrease. Also, it is found that the overall electrochemical properties of the alloys first augment and then fall with the annealing temperature rising.展开更多
Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effecti...Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors.展开更多
A low-cost 1D cobalt-based coordination polymer(CP)[Co(BGPD)(DMSO)_(2)(H_(2)O)_(2)](Co-BD;H2BGPD=N,N'-bis(glycinyl)pyromellitic diimide;DMSO=dimethyl sulfoxide)was synthesized by a simple method,and its crystal st...A low-cost 1D cobalt-based coordination polymer(CP)[Co(BGPD)(DMSO)_(2)(H_(2)O)_(2)](Co-BD;H2BGPD=N,N'-bis(glycinyl)pyromellitic diimide;DMSO=dimethyl sulfoxide)was synthesized by a simple method,and its crystal structure was characterized.In a three-electrode system,Co-BD,as the electrode material for supercapacitors,achieved a specific capacitance of 830 F·g^(-1)at 1 A·g^(-1),equivalent to a specific capacity of 116.4 mAh·g^(-1),and exhibited high-rate capability,reaching 212 F·g^(-1)at 20 A·g^(-1).Impressively,Co-BD||rGO(reduced graphene oxide),representing an asymmetrical supercapacitor,owns a higher energy density of 14.2 Wh·kg^(-1)at 0.80 kW·kg^(-1),and an excellent cycle performance(After 4000 cycles at 1 A·g^(-1),the capacitance retention was up to 94%).CCDC:2418872.展开更多
基金financially supported by University-level key projects of Anhui University of Science and Technology(QNZD2021-04,QNZD2021-07)Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2021yjrc22,13210572)+2 种基金Huainan Science and Technology Bureau Plan Project(2023A3111)Open Research Fund Program of Engineering Technology Research Center of Coal Resources Comprehensive Utilization(MTYJZX202204)Natural Science Research Project of Anhui Educational Committee(2023AH051184,2023AH051210)。
文摘Carbon materials with adjustable porosity,controllable het-eroatom doping and low-cost have been received considerable attention as supercapacitor electrodes.However,using carbon materials with abundant micropores,a high surface area and a high-dopant content for an aqueous su-percapacitor with a high energy output still remains a challenge.We report the easy synthesis of interconnected carbon spheres by a polymerization re-action between p-benzaldehyde and 2,6-diaminopyridine.The synthesis in-volves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output,which are attributed to the high ion-accessible area provided by the large number of micropores,high N/O contents and rapid ion diffusion channels in the porous structure.At a PMEC∶KOH mass ratio of 1∶1,the high electrolyte ion-adsorption area(2599.76 m^(2) g^(−1))and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity(303.2 F g^(−1)@0.5 A g^(−1))giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg^(−1)@250 W kg^(−1).This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.
基金Projects(51161015,50961009) supported by the National Natural Science Foundation of ChinaProject(2011AA03A408) supported by the National High Technology Research and Development Program of ChinaProjects(2011ZD10,2010ZD05) supported by the Natural Science Foundation of Inner Mongolia,China
文摘For the purpose of improving the electrochemical cycle stability of the La-Mg-Ni based A2BT-type electrode alloys, both reducing Mg content and substituting La with Pr were adopted. The Lao.8-xPrxMg0.2Ni3.15Co0.2A10.1Si0.05 （x=0, 0.1, 0.2, 0.3, 0.4） electrode alloys were fabricated by casting and annealing. The investigation on the structures and electrochemical performances of the alloys was performed. The obtained results reveal that the as-cast and annealed alloys comprise two major phases, （La, Mg）2Ni7 phase with the hexagonal Ce2NiT-type structure and LaNi5 phase with the hexagonal CaCus-type structure, as well as a little residual LaNi3 phase. It is also found that the addition of Pr element observably affects the electrochemical hydrogen storage characteristics of the alloys, just as the discharge capacity and high rate discharge ability （HRD） first rise then fall with the growing of Pr content, and among all the alloys, the as-cast and annealed （x=0.3） alloys generate the largest discharge capacities of 360.8 and 386.5 mA.h/g, respectively. Additionally, the electrochemical cycle stability of all the alloys markedly grows with the increase of Pr content. The capacity retaining rate （S100） at the 100th charging and discharging cycle is enhanced from 64.98% to 77.55% for the as-cast alloy, and from 76.60% to 95.72% for the as-annealed alloy by rising Pr content from 0 to 0.4. Furthermore, the substitution of Pr for La results in first increase and then decrease in the hydrogen diffusion coefficient （D）, the limiting current density （IL） as well as the electrochemical impedance.
基金Projects(51371094,51161015)supported by the National Natural Science Foundations of ChinaProject(2011ZD10)supported by Natural Science Foundation of Inner Mongolia,China
文摘The La-Mg-Ni-based A2B7-type La0.5Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The influences of the additional silicon and the annealing treatment on the structure and electrochemical performances of the alloys were investigated systemically. Both of the analyses of XRD and SEM reveal that the as-cast and annealed alloys are of a multiphase structure, involving two main phases （La, Mg）2Ni7 and LaNi5 as well as one minor phase LaNi3. The addition of Si and annealing treatment bring on an evident change in the phase abundances and cell parameters of （La, Mg）2Ni7 and LaNi5 phase for the alloy without altering its phase structure. The phase abundances decrease from 74.3% （x=0） to 57.8% （x=0.2） for the （La, Mg）2Ni7 phase, and those of LaNi5 phase increase from 20.2% （x^0） to 37.3% （x=0.2）. As for the electrochemical measurements, adding Si and performing annealing treatment have engendered obvious impacts. The cycle stability of the alloys is improved dramatically, being enhanced from 80.3% to 93.7% for the as-annealed （950 ℃） alloys with Si content increasing from 0 to 0.2. However, the discharge capacity is reduced by adding Si, from 399.4 to 345.3 mA.h/g as the Si content increases from 0 to 0.2. Furthermore, such addition makes the electrochemical kinetic properties of the alloy electrodes first increase and then decrease. Also, it is found that the overall electrochemical properties of the alloys first augment and then fall with the annealing temperature rising.
文摘Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors.
文摘A low-cost 1D cobalt-based coordination polymer(CP)[Co(BGPD)(DMSO)_(2)(H_(2)O)_(2)](Co-BD;H2BGPD=N,N'-bis(glycinyl)pyromellitic diimide;DMSO=dimethyl sulfoxide)was synthesized by a simple method,and its crystal structure was characterized.In a three-electrode system,Co-BD,as the electrode material for supercapacitors,achieved a specific capacitance of 830 F·g^(-1)at 1 A·g^(-1),equivalent to a specific capacity of 116.4 mAh·g^(-1),and exhibited high-rate capability,reaching 212 F·g^(-1)at 20 A·g^(-1).Impressively,Co-BD||rGO(reduced graphene oxide),representing an asymmetrical supercapacitor,owns a higher energy density of 14.2 Wh·kg^(-1)at 0.80 kW·kg^(-1),and an excellent cycle performance(After 4000 cycles at 1 A·g^(-1),the capacitance retention was up to 94%).CCDC:2418872.
