Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient ...Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium-sulfur batteries, lithium-oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal-air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density, and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
Designing a better carbon framework is critical for harnessing the high theoretical capacity of Li-S batteries and avoiding their drawbacks, such as the insulating nature of sulfur, active material loss, and the polys...Designing a better carbon framework is critical for harnessing the high theoretical capacity of Li-S batteries and avoiding their drawbacks, such as the insulating nature of sulfur, active material loss, and the polysulfide shuttle reaction. Here, we report an ingenious design of hollow carbon nanofibers with closed ends and protogenetic mesopores in the shell that can be retracted to micropores after sulfur infusion. Such dynamic adjustable pore sizes ensure a high sulfur loading, and more importantly, eliminate excessive contact of sulfur species with the electrolyte. Together, the high aspect ratio and thin carbon shells of the carbon nanofibers facilitate rapid transport of Li^＋ ions and electrons, and the closed-end structure of the carbon nanofibers further blocks polysulfide dissolution from both ends, which is remarkably different from that for carbon nanotubes with open ends. The obtained sulfur-carbon cathodes exhibit excellent performance marked by high sulfur utilization, superior rate capability （1,170, 1,050, and 860 mA.h.g-1 at 1.0, 2.0, and 4.0 C （1 C = 1.675 A·g^-1）, respectively）, and a stable reversible capacity of 847 mA·h·g^-1 after 300 cycles at a high rate of 2.0 C.展开更多
The effect of thickness (1 similar to 10 mm) of the ingots on the electrochemical properties of as-cast and annealed strip cast LPCNi3.55Co0.75Mn0.4Al0.3 hydrogen storage alloys was investigated. It is found that the ...The effect of thickness (1 similar to 10 mm) of the ingots on the electrochemical properties of as-cast and annealed strip cast LPCNi3.55Co0.75Mn0.4Al0.3 hydrogen storage alloys was investigated. It is found that the 0.2 C discharge capacity of as-cast LPCNi3.55Co0.75Mn0.4Al0.3 alloy increases with the increase of the thickness of the ingots. As-east alloy with the thickness of 10 mm shows better activation property, higher 1C discharge capacity and better cyclic stability than others. It is mainly contributed to its larger unit cell volume and less internal stress. Annealed LPCNi3.55Co0.75Mn0.4Al0.3 alloy with the thickness of 3 mm shows much better comprehensive electrochemical properties than as-east one; The cyclic. stability of the alloy with the thickness of 6 mm and the activation properties of the alloys with the thickness of 3 similar to 6 mm are improved after annealing. It is mainly owing to the great release of internal stress and the decrease of the segregation of Mn in the alloys.展开更多
Potassium-ion batteries（KIBs） are a promising alternative to lithium-ion batteries owning to the abundance of potassium on Earth and the relatively low K/K＋redox couple. To date, KIBs remains its infancy and the in...Potassium-ion batteries（KIBs） are a promising alternative to lithium-ion batteries owning to the abundance of potassium on Earth and the relatively low K/K＋redox couple. To date, KIBs remains its infancy and the investigation of anode materials mainly focused on carbon-based materials, which deliver limited reversible capacity. Hence, it is imperative to explore alternative anode materials with high reversible capacity for KIBs. Recently, a pioneering work from Chen’s group reported a nanocomposite of Sb2S3 nanoparticles anchored on porous S,N-codoped graphene（denoted as Sb2S3-SNG） as an advanced anode material for KIBs, which exhibited remarkable enhancements of both capacity and cycling stability, highlighting the rational structure design of Sb2S3-SNG for maximum utilization of Sb2S3 nanoparticles and graphene layers for energy storage applications in high-performance KIBs.展开更多
A new photon-in/photon-out endstation at beamline 02B02 of the Shanghai Synchrotron Radiation Facility for studying the electronic structure of energy materials has been constructed and fully opened to users.The endst...A new photon-in/photon-out endstation at beamline 02B02 of the Shanghai Synchrotron Radiation Facility for studying the electronic structure of energy materials has been constructed and fully opened to users.The endstation has the capability to perform soft x-ray absorption spectroscopy in total electron yield and total fluorescence yield modes simultaneously.The photon energy ranges from 40 eV to 2000 eV covering the K-edge of most low Z-elements and the L-edge of 3d transition-metals.The new self-designed channeltron detector allows us to achieve good fluorescence signals at the low photon flux.In addition,we synchronously collect the signals of a standard reference sample and a gold mesh on the upstream to calibrate the photon energy and monitor the beam fluctuation,respectively.In order to cross the pressure gap,in situ gas and liquid cells for soft x-ray absorption spectroscopy are developed to study the samples under realistic working conditions.展开更多
The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatur...The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.展开更多
基金supported by the National Key Research and Development Program (no.2016YFA0202500)National Basic Research Program of China (2015CB932500)the Natural Scientific Foundation of China (nos.21306102 and 21422604)
文摘Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium-sulfur batteries, lithium-oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal-air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density, and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金This work was supported by the National Basic Research Program of China （No. 2013CB934104）, the National Natural Science Foundation of China （Nos. 21225312 and 21376047）, and Cheung Kong Scholars Program of China （No. T2015036）.
文摘Designing a better carbon framework is critical for harnessing the high theoretical capacity of Li-S batteries and avoiding their drawbacks, such as the insulating nature of sulfur, active material loss, and the polysulfide shuttle reaction. Here, we report an ingenious design of hollow carbon nanofibers with closed ends and protogenetic mesopores in the shell that can be retracted to micropores after sulfur infusion. Such dynamic adjustable pore sizes ensure a high sulfur loading, and more importantly, eliminate excessive contact of sulfur species with the electrolyte. Together, the high aspect ratio and thin carbon shells of the carbon nanofibers facilitate rapid transport of Li^＋ ions and electrons, and the closed-end structure of the carbon nanofibers further blocks polysulfide dissolution from both ends, which is remarkably different from that for carbon nanotubes with open ends. The obtained sulfur-carbon cathodes exhibit excellent performance marked by high sulfur utilization, superior rate capability （1,170, 1,050, and 860 mA.h.g-1 at 1.0, 2.0, and 4.0 C （1 C = 1.675 A·g^-1）, respectively）, and a stable reversible capacity of 847 mA·h·g^-1 after 300 cycles at a high rate of 2.0 C.
文摘The effect of thickness (1 similar to 10 mm) of the ingots on the electrochemical properties of as-cast and annealed strip cast LPCNi3.55Co0.75Mn0.4Al0.3 hydrogen storage alloys was investigated. It is found that the 0.2 C discharge capacity of as-cast LPCNi3.55Co0.75Mn0.4Al0.3 alloy increases with the increase of the thickness of the ingots. As-east alloy with the thickness of 10 mm shows better activation property, higher 1C discharge capacity and better cyclic stability than others. It is mainly contributed to its larger unit cell volume and less internal stress. Annealed LPCNi3.55Co0.75Mn0.4Al0.3 alloy with the thickness of 3 mm shows much better comprehensive electrochemical properties than as-east one; The cyclic. stability of the alloy with the thickness of 6 mm and the activation properties of the alloys with the thickness of 3 similar to 6 mm are improved after annealing. It is mainly owing to the great release of internal stress and the decrease of the segregation of Mn in the alloys.
基金supported by the National Key Research and Development Program (No. 2016YFA0202500)
文摘Potassium-ion batteries（KIBs） are a promising alternative to lithium-ion batteries owning to the abundance of potassium on Earth and the relatively low K/K＋redox couple. To date, KIBs remains its infancy and the investigation of anode materials mainly focused on carbon-based materials, which deliver limited reversible capacity. Hence, it is imperative to explore alternative anode materials with high reversible capacity for KIBs. Recently, a pioneering work from Chen’s group reported a nanocomposite of Sb2S3 nanoparticles anchored on porous S,N-codoped graphene（denoted as Sb2S3-SNG） as an advanced anode material for KIBs, which exhibited remarkable enhancements of both capacity and cycling stability, highlighting the rational structure design of Sb2S3-SNG for maximum utilization of Sb2S3 nanoparticles and graphene layers for energy storage applications in high-performance KIBs.
基金Project supported by the National Natural Science Foundation of China(Grant No.11227902)as part of NSFC ME2 beamline project,Science and Technology Commission of Shanghai Municipality,China(Grant No.14520722100)the National Natural Science Foundation of China(Grant Nos.11905283 and U1632269)
文摘A new photon-in/photon-out endstation at beamline 02B02 of the Shanghai Synchrotron Radiation Facility for studying the electronic structure of energy materials has been constructed and fully opened to users.The endstation has the capability to perform soft x-ray absorption spectroscopy in total electron yield and total fluorescence yield modes simultaneously.The photon energy ranges from 40 eV to 2000 eV covering the K-edge of most low Z-elements and the L-edge of 3d transition-metals.The new self-designed channeltron detector allows us to achieve good fluorescence signals at the low photon flux.In addition,we synchronously collect the signals of a standard reference sample and a gold mesh on the upstream to calibrate the photon energy and monitor the beam fluctuation,respectively.In order to cross the pressure gap,in situ gas and liquid cells for soft x-ray absorption spectroscopy are developed to study the samples under realistic working conditions.
文摘The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.
