During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other...During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other than advanced battery materials,in-depth understanding of the intrinsic mechanism correlated with cell reaction is also essential for the development of high-performance Li-ion battery.Advanced characterization techniques,especially neutron-based techniques,have greatly promoted Li-ion battery researches.In this review,the characteristics or capabilities of various neutron-based characterization techniques,including elastic neutron scattering,quasi-elastic neutron scattering,neutron imaging,and inelastic neutron scattering,for the related Li-ion-battery researches are summarized.The design of in-situ/operando environment is also discussed.The comprehensive survey on neutron-based characterizations for mechanism understanding will provide guidance for the further study of high-performance Li-ion batteries.展开更多
Crystallographic structure, magnetic properties, and magnetic entropy change of the Cr-based spinel sulfides Co1-xCuxCr2S4 （x =0-0.8） have been investigated. All these compounds crystallize into the cubic spinel str...Crystallographic structure, magnetic properties, and magnetic entropy change of the Cr-based spinel sulfides Co1-xCuxCr2S4 （x =0-0.8） have been investigated. All these compounds crystallize into the cubic spinel structure, the Cu substitution shrinks linearly the lattice constant at a ratio of 0.0223 A per Cu atom in the unit cell, and enhances linearly the Curie temperature and the spontaneous magnetization at the rates of 18 K and 0.33 μB/f.u, per Cu atom in the unit cell, respectively. All these compounds show a typical behavior of second order magnetic transition, and a room temperature magnetic entropy change of 2.57 J/kg.K is achieved for Co0.4Cu0.6Cr2S4.展开更多
Nanostructuring, structure distortion, and/or disorder are the main manipulation techniques to reduce the lattice thermal conductivity and improve the figure of merit of thermoelectric materials. A single-phase α-MgA...Nanostructuring, structure distortion, and/or disorder are the main manipulation techniques to reduce the lattice thermal conductivity and improve the figure of merit of thermoelectric materials. A single-phase α-MgAgSb sample, MgAg0.97Sb0.99, with high thermoelectric performance in near room temperature region was synthesized through a high-energy ball milling with a hot-pressing method. Here, we report the average grain size of 24–28 nm and the accurate structure distortion, which are characterized by high-resolution neutron diffraction and synchrotron x-ray diffraction with Rietveld refinement data analysis. Both the small grain size and the structure distortion have a contribution to the low lattice thermal conductivity in MgAg0.97Sb0.99.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0401503)the National Materials Genome Project of China(Grant No.2016YFB0100106)the National Natural Science Foundation of China(Grant No.11675255)
文摘During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other than advanced battery materials,in-depth understanding of the intrinsic mechanism correlated with cell reaction is also essential for the development of high-performance Li-ion battery.Advanced characterization techniques,especially neutron-based techniques,have greatly promoted Li-ion battery researches.In this review,the characteristics or capabilities of various neutron-based characterization techniques,including elastic neutron scattering,quasi-elastic neutron scattering,neutron imaging,and inelastic neutron scattering,for the related Li-ion-battery researches are summarized.The design of in-situ/operando environment is also discussed.The comprehensive survey on neutron-based characterizations for mechanism understanding will provide guidance for the further study of high-performance Li-ion batteries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274369,51472210,and 11675255)
文摘Crystallographic structure, magnetic properties, and magnetic entropy change of the Cr-based spinel sulfides Co1-xCuxCr2S4 （x =0-0.8） have been investigated. All these compounds crystallize into the cubic spinel structure, the Cu substitution shrinks linearly the lattice constant at a ratio of 0.0223 A per Cu atom in the unit cell, and enhances linearly the Curie temperature and the spontaneous magnetization at the rates of 18 K and 0.33 μB/f.u, per Cu atom in the unit cell, respectively. All these compounds show a typical behavior of second order magnetic transition, and a room temperature magnetic entropy change of 2.57 J/kg.K is achieved for Co0.4Cu0.6Cr2S4.
基金Project supported by the National Natural Science Foundation of China(Grant No.11675255)the National Key R&D Program of China(Grant No.2016YFA0401503).
文摘Nanostructuring, structure distortion, and/or disorder are the main manipulation techniques to reduce the lattice thermal conductivity and improve the figure of merit of thermoelectric materials. A single-phase α-MgAgSb sample, MgAg0.97Sb0.99, with high thermoelectric performance in near room temperature region was synthesized through a high-energy ball milling with a hot-pressing method. Here, we report the average grain size of 24–28 nm and the accurate structure distortion, which are characterized by high-resolution neutron diffraction and synchrotron x-ray diffraction with Rietveld refinement data analysis. Both the small grain size and the structure distortion have a contribution to the low lattice thermal conductivity in MgAg0.97Sb0.99.
