Additive manufacturing of self-supported carbon-transition metal compound electrodes is crucial for enhancing water splitting processes for sustainable hydrogen production.To overcome interfacial bonding issues,our st...Additive manufacturing of self-supported carbon-transition metal compound electrodes is crucial for enhancing water splitting processes for sustainable hydrogen production.To overcome interfacial bonding issues,our study introduces a novel fabrication of carbon-metal phosphide electrodes,yielding efficient water splitting results.Nitrogen and cobalt-rich scaffolds were produced via extrusion-based printing with chitosan-zeolitic imidazolate framework(ZIF)ink,which,upon pyrolysis,converted into nitrogen-doped carbon frameworks that anchored Ni-Co-P nanosheets.Optimizing ZIF-67 in the ink modulates Ni-Co-P density,and via integration with the symmetric triblock copolymer,polyethylene oxide-polypropylene oxide-polyethylene oxide(P123),mesoporosity was created,forming a hierarchical porous structure that facilitated swift mass,charge,and ion transport,and promoted site accessibility.Electrochemical testing revealed overpotentials of 57 mVat−10 mA cm^(−2)and 263 mV at−500 mA cm^(−2)for the hydrogen evolution reaction,withstanding 1000 h of cycling at−10 mA cm^(−2).The oxygen evolution reaction exhibited an overpotential of 163 mV at 10 mA cm^(−2),and 260 h of cycling durability,outperforming traditional nickel foam electrodes.Functioning both as anode and cathode,the electrode attained a voltage of 1.43 V at 10 mA cm^(−2),maintaining stability for over 200 h.This research contributes significantly to the practical application of additive manufactured electrodes in energy conversion/storage,environmental,and electronic fields,marking a significant advancement in the domain of green energy technologies.展开更多
Lithium-ion hybrid supercapacitors （LIHSs）, also called Li-ion capacitors, are electrochemical energy stor- age devices that combining the advantages of high power density of supercapacitor and high energy density o...Lithium-ion hybrid supercapacitors （LIHSs）, also called Li-ion capacitors, are electrochemical energy stor- age devices that combining the advantages of high power density of supercapacitor and high energy density of Li-ion battery. However, high power density and long cycle life are still challenges for the cul~ rent LIHSs due to the imbalance of charge-storage capacity and electrode kinetics between capacitor-type cathode and battery-type anode. Therefore, great efforts have been made on designing novel cathode materials with high storage capacity and anode material with enhanced kinetic behavior for LIHSs. With unique two-dimensional form and numerous appealing properties, for the past several years, the rational designed graphene and its composites materials exhibit greatly improved electrochemical performance as cathode or anode for LIHSs. Here, we summarized and discussed the latest advances of the state- of-art graphene-based materials for LIHSs applications. The major roles of graphene are highlighted as （1） a superior active material, （2） ultrathin 2D flexible support to remedy the sluggish reaction of the metal compound anode, and （3） good 2D building blocks for constructing macroscopic 3D pOFOUS car- bonjgraphene hybrids. In addition, some high performance aqueous LIHSs using graphene as electrode were also summarized. Finally, the perspectives and challenges are also proposed for further develop- ment of more advanced graphene-based LIHSs.展开更多
Thermal conductivity is one of key parameters of adsorbents, which will affect the overall system performance of adsorption chiller. To improve adsorbent＇s thermal conductivity is always one of research focuses in ch...Thermal conductivity is one of key parameters of adsorbents, which will affect the overall system performance of adsorption chiller. To improve adsorbent＇s thermal conductivity is always one of research focuses in chemisorption field. A new chemical composite adsorbent is fabricated by adding carbon coated metal（Aluminum and Nickel） nanoparticles with three different addition amounts into the mixture of chloride salts and natural expanded graphite aiming to improve the thermal conductivity. The preparation processes and its thermal conductivity of this novel composite adsorbent are reported and summarized. Experimental results indicate that the nanoparticles are homogenously dispersed in the composite adsorbent by applying the reported preparation processes. The thermal conductivity of the composite adsorbent can averagely enlarge by 20% when the weight ratio of the added nanoparticles is 10 wt%. Moreover, carbon coated aluminum nanoparticles exhibit more effective enlargement in thermal conductivity than nickel nanoparticles. As for the composite adsorbent of CaCl2-NEG, there is a big reinforcement from 30% to 50% for Al@C nanoparticles, however only 10% in maximum caused by Ni@C nanoparticles. The proposed research provides a methodology to design and prepare thermal conductive chemical composite adsorbent.展开更多
The constant increase in power and heat flux densities encountered in electronic devices fuels a rising demand for lightweight heat sink materials with suitable thermal properties.In this study,discontinuous pitch-bas...The constant increase in power and heat flux densities encountered in electronic devices fuels a rising demand for lightweight heat sink materials with suitable thermal properties.In this study,discontinuous pitch-based carbon fiber reinforced aluminum matrix（Al-CF） composites with aluminum–silicon alloy（Al–Si） were fabricated through hot pressing.The small amount of Al–Si contributed to enhance the sintering process in order to achieve fully dense Al–CF composites.A thermal conductivity and CTE of 258 W/（m K） and 7.0 9 10-6/K in the in-plane direction of the carbon fibers were obtained for a（Al95 vol%＋ Al–Si5 vol%）-CF50 vol%composite.Carbon fiber provides the reducing of CTE while the conservation of thermal conductivity and weight of Al.The achieved CTEs satisfy the standard requirements for a heat sink material,which furthermore possess a specific thermal conductivity of 109 W cm3/（m K g）.This simple process allows the low-cost fabrication of Al–CF composite,which is applicable for a lightweight heat sink material.展开更多
基金supported by funding from the National Key Research and Development Program of China(grant no.2022YFB1105100)the National Natural Science Foundation of China(NSFC,grant no.U2330105)the Science Foundation of China University of Petroleum,Beijing(grant no.24620188JC005).
文摘Additive manufacturing of self-supported carbon-transition metal compound electrodes is crucial for enhancing water splitting processes for sustainable hydrogen production.To overcome interfacial bonding issues,our study introduces a novel fabrication of carbon-metal phosphide electrodes,yielding efficient water splitting results.Nitrogen and cobalt-rich scaffolds were produced via extrusion-based printing with chitosan-zeolitic imidazolate framework(ZIF)ink,which,upon pyrolysis,converted into nitrogen-doped carbon frameworks that anchored Ni-Co-P nanosheets.Optimizing ZIF-67 in the ink modulates Ni-Co-P density,and via integration with the symmetric triblock copolymer,polyethylene oxide-polypropylene oxide-polyethylene oxide(P123),mesoporosity was created,forming a hierarchical porous structure that facilitated swift mass,charge,and ion transport,and promoted site accessibility.Electrochemical testing revealed overpotentials of 57 mVat−10 mA cm^(−2)and 263 mV at−500 mA cm^(−2)for the hydrogen evolution reaction,withstanding 1000 h of cycling at−10 mA cm^(−2).The oxygen evolution reaction exhibited an overpotential of 163 mV at 10 mA cm^(−2),and 260 h of cycling durability,outperforming traditional nickel foam electrodes.Functioning both as anode and cathode,the electrode attained a voltage of 1.43 V at 10 mA cm^(−2),maintaining stability for over 200 h.This research contributes significantly to the practical application of additive manufactured electrodes in energy conversion/storage,environmental,and electronic fields,marking a significant advancement in the domain of green energy technologies.
基金supported by the National Nature Science Foundations of China(Grant No.21673263,21573265)the Independent Innovation Plan Foundations of Qingdao City of China(Grant No.16-5-1-42-jch)the western Young Scholars Foundations of Chinese Academy of Sciences
文摘Lithium-ion hybrid supercapacitors （LIHSs）, also called Li-ion capacitors, are electrochemical energy stor- age devices that combining the advantages of high power density of supercapacitor and high energy density of Li-ion battery. However, high power density and long cycle life are still challenges for the cul~ rent LIHSs due to the imbalance of charge-storage capacity and electrode kinetics between capacitor-type cathode and battery-type anode. Therefore, great efforts have been made on designing novel cathode materials with high storage capacity and anode material with enhanced kinetic behavior for LIHSs. With unique two-dimensional form and numerous appealing properties, for the past several years, the rational designed graphene and its composites materials exhibit greatly improved electrochemical performance as cathode or anode for LIHSs. Here, we summarized and discussed the latest advances of the state- of-art graphene-based materials for LIHSs applications. The major roles of graphene are highlighted as （1） a superior active material, （2） ultrathin 2D flexible support to remedy the sluggish reaction of the metal compound anode, and （3） good 2D building blocks for constructing macroscopic 3D pOFOUS car- bonjgraphene hybrids. In addition, some high performance aqueous LIHSs using graphene as electrode were also summarized. Finally, the perspectives and challenges are also proposed for further develop- ment of more advanced graphene-based LIHSs.
基金Supported by National Natural Science Foundation of China(No.51276044)Science and Technology Planning Project of Guangdong Province,China(Grant Nos.2015A050502047,2015B010135011)+3 种基金Science and Technology Planning Project of Guangzhou City,China(Grant Nos.201508030018,2016201604030040)Youth Foundation of Guangdong University of Technology,China(Grant No.252151038)EPSRC Grants(Grant Nos.EP/I027904/1,EP/K004689/1,EP/M008088/1)IChemE Global Awards 2015:MCSA for FP&VA
文摘Thermal conductivity is one of key parameters of adsorbents, which will affect the overall system performance of adsorption chiller. To improve adsorbent＇s thermal conductivity is always one of research focuses in chemisorption field. A new chemical composite adsorbent is fabricated by adding carbon coated metal（Aluminum and Nickel） nanoparticles with three different addition amounts into the mixture of chloride salts and natural expanded graphite aiming to improve the thermal conductivity. The preparation processes and its thermal conductivity of this novel composite adsorbent are reported and summarized. Experimental results indicate that the nanoparticles are homogenously dispersed in the composite adsorbent by applying the reported preparation processes. The thermal conductivity of the composite adsorbent can averagely enlarge by 20% when the weight ratio of the added nanoparticles is 10 wt%. Moreover, carbon coated aluminum nanoparticles exhibit more effective enlargement in thermal conductivity than nickel nanoparticles. As for the composite adsorbent of CaCl2-NEG, there is a big reinforcement from 30% to 50% for Al@C nanoparticles, however only 10% in maximum caused by Ni@C nanoparticles. The proposed research provides a methodology to design and prepare thermal conductive chemical composite adsorbent.
文摘The constant increase in power and heat flux densities encountered in electronic devices fuels a rising demand for lightweight heat sink materials with suitable thermal properties.In this study,discontinuous pitch-based carbon fiber reinforced aluminum matrix（Al-CF） composites with aluminum–silicon alloy（Al–Si） were fabricated through hot pressing.The small amount of Al–Si contributed to enhance the sintering process in order to achieve fully dense Al–CF composites.A thermal conductivity and CTE of 258 W/（m K） and 7.0 9 10-6/K in the in-plane direction of the carbon fibers were obtained for a（Al95 vol%＋ Al–Si5 vol%）-CF50 vol%composite.Carbon fiber provides the reducing of CTE while the conservation of thermal conductivity and weight of Al.The achieved CTEs satisfy the standard requirements for a heat sink material,which furthermore possess a specific thermal conductivity of 109 W cm3/（m K g）.This simple process allows the low-cost fabrication of Al–CF composite,which is applicable for a lightweight heat sink material.
