Nano-CaCO3 particles were surface-coated with SiO2 by the sol-gel method and used as the high temperature CO2 adsorption material.CaCO3 samples prepared at 60—90℃ were characterized with TEM, EDS and XRD methods and...Nano-CaCO3 particles were surface-coated with SiO2 by the sol-gel method and used as the high temperature CO2 adsorption material.CaCO3 samples prepared at 60—90℃ were characterized with TEM, EDS and XRD methods and the initial and final decomposition temperature were determined with TGA.The CO2 adsorption ratio and carbonation-calcination characteristics were evaluated in a 12 mm fixed bed reactor.The analytical results showed that there was an amorphous SiO2 film formed on the surface of nano-CaCO3,and the atomic ratio of Si to Ca is 1∶39.The initial and final decomposition temperatures were 595—620℃ and 800—820℃ respectively.The maximum CO2 adsorption ratio of SiO2 coated with nano-CaCO3 was 92.1% at 600℃with a 10% increase as compared with the uncoated nano-CaCO3 particles.After 20 cyclic carbonation and calcination runs, CO2 adsorption ratio of the SiO2 coated samples was 63%.The XRD analysis illustrated that the crystal type of nano-CaCO3 had no change after 20 cyclic runs.展开更多
Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimiz...Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimize sulfur utilization and enhance cycle stability as well. In this work hollow-in-hollow carbon spheres with hollow foam-like cores （HCSF@C） are prepared to improve both capability and cycling stability of lithium-sulfur batteries. With high surface area and large pore volumes, the loading of sulfur in HCSF@C reaches up to 70 wt.%. In the resulting S/HCSF@C composites, the outer carbon shell serves as an effective protection layer to trap the soluble polysulfide intermediates derived from the inner component. Consequently, the S/HCSF@C cathode retains a high capacity of 780 mAh/g after 300 cycles at a high charge/discharge rate of 1 A/g.展开更多
There have been few reports concerning the hydrothermal synthesis of silicon anode materials. In this manuscript, starting from the very cheap silica sol, we hydrothermally prepared porous silicon nanospheres in an au...There have been few reports concerning the hydrothermal synthesis of silicon anode materials. In this manuscript, starting from the very cheap silica sol, we hydrothermally prepared porous silicon nanospheres in an autoclave at 180 ℃. As anode materials for lithium-ion batteries （LIBs）, the as-prepared nano-silicon anode without any carbon coating delivers a high reversible specific capacity of 2,650 mAh·g^-1 at 0.36 A·g^-1 and a significant cycling stability of about 950 mAh·g^-1 at 3.6 A·g^-1 during 500 cycles.展开更多
Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish ...Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers(Sb@CN nanofibers)were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 m Ah g-1 after 200 cycles at 50 m A g-1, and a particularly stable capacity of 212.7 m Ah g-1 was also obtained after 1000 cycles even at 5000 m A g-1. Given such outstanding electrochemical performances,this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.展开更多
A novel all-solid-state, coaxial, fiber-shaped asymmetric supercapacitor has been fabricated by wrapping a conducting carbon paper on a MnO2-modified nanoporous gold wire. This energy wire exhibits high capacitance of...A novel all-solid-state, coaxial, fiber-shaped asymmetric supercapacitor has been fabricated by wrapping a conducting carbon paper on a MnO2-modified nanoporous gold wire. This energy wire exhibits high capacitance of 12 mF.cm^-2 and energy density of 5.4 μW.h.cm^-2 with excellent cycling stability. Hierarchical nanostructures and coaxial architectural design facilitate effective contacts between the two core@sheath electrodes and active layers with high flexibility and high performance. This work provides the first example of coaxial fiber- shaped asymmetric supercapacitors with an operation voltage of 1.8 V, and holds great potential for future flexible electronic devices.展开更多
文摘Nano-CaCO3 particles were surface-coated with SiO2 by the sol-gel method and used as the high temperature CO2 adsorption material.CaCO3 samples prepared at 60—90℃ were characterized with TEM, EDS and XRD methods and the initial and final decomposition temperature were determined with TGA.The CO2 adsorption ratio and carbonation-calcination characteristics were evaluated in a 12 mm fixed bed reactor.The analytical results showed that there was an amorphous SiO2 film formed on the surface of nano-CaCO3,and the atomic ratio of Si to Ca is 1∶39.The initial and final decomposition temperatures were 595—620℃ and 800—820℃ respectively.The maximum CO2 adsorption ratio of SiO2 coated with nano-CaCO3 was 92.1% at 600℃with a 10% increase as compared with the uncoated nano-CaCO3 particles.After 20 cyclic carbonation and calcination runs, CO2 adsorption ratio of the SiO2 coated samples was 63%.The XRD analysis illustrated that the crystal type of nano-CaCO3 had no change after 20 cyclic runs.
基金We thank the National Basic Research Program of China （Nos. 2011CB932403 and 2015CB932300） and the National Natural Science Foundation of China （Nos. 21301144, 21390390, 21131005, 21333008, and 21420102001） for financial support.
文摘Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimize sulfur utilization and enhance cycle stability as well. In this work hollow-in-hollow carbon spheres with hollow foam-like cores （HCSF@C） are prepared to improve both capability and cycling stability of lithium-sulfur batteries. With high surface area and large pore volumes, the loading of sulfur in HCSF@C reaches up to 70 wt.%. In the resulting S/HCSF@C composites, the outer carbon shell serves as an effective protection layer to trap the soluble polysulfide intermediates derived from the inner component. Consequently, the S/HCSF@C cathode retains a high capacity of 780 mAh/g after 300 cycles at a high charge/discharge rate of 1 A/g.
文摘There have been few reports concerning the hydrothermal synthesis of silicon anode materials. In this manuscript, starting from the very cheap silica sol, we hydrothermally prepared porous silicon nanospheres in an autoclave at 180 ℃. As anode materials for lithium-ion batteries （LIBs）, the as-prepared nano-silicon anode without any carbon coating delivers a high reversible specific capacity of 2,650 mAh·g^-1 at 0.36 A·g^-1 and a significant cycling stability of about 950 mAh·g^-1 at 3.6 A·g^-1 during 500 cycles.
基金supported by the National Natural Science Foundation of China(51904342,51622406,and 21673298)the National Postdoctoral Program for Innovative Talents(BX201600192)+4 种基金Central South University Postdoctoral Foundation(140050018)China Postdoctoral Science Foundation(2017 M6203552)the National Key Research and Development Program of China(2017YFB0102000,2018YFB0104200)Hunan Provincial Science and Technology Plan(2017TP1001)the Fundamental Research Funds for the Central Universities of Central South University(2019zzts431,2019zzts433)。
文摘Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers(Sb@CN nanofibers)were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 m Ah g-1 after 200 cycles at 50 m A g-1, and a particularly stable capacity of 212.7 m Ah g-1 was also obtained after 1000 cycles even at 5000 m A g-1. Given such outstanding electrochemical performances,this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.
文摘A novel all-solid-state, coaxial, fiber-shaped asymmetric supercapacitor has been fabricated by wrapping a conducting carbon paper on a MnO2-modified nanoporous gold wire. This energy wire exhibits high capacitance of 12 mF.cm^-2 and energy density of 5.4 μW.h.cm^-2 with excellent cycling stability. Hierarchical nanostructures and coaxial architectural design facilitate effective contacts between the two core@sheath electrodes and active layers with high flexibility and high performance. This work provides the first example of coaxial fiber- shaped asymmetric supercapacitors with an operation voltage of 1.8 V, and holds great potential for future flexible electronic devices.
