The oxidation states of Ge nanoparticles in the surface layer of Ge/Si film were studied by X-ray photoelectron spectroscopy. New features appeared at the high binding energy side of the XPS Ge 3d peak when samples we...The oxidation states of Ge nanoparticles in the surface layer of Ge/Si film were studied by X-ray photoelectron spectroscopy. New features appeared at the high binding energy side of the XPS Ge 3d peak when samples were annealed in atmosphere, which were caused by the large interfacial area between the Ge and Si nanoparticles, as well as by the change in environment of the Ge nanoparticles and the oxidation states of Ge and Si.展开更多
An aerosol spray pyrolysis technique is used to synthesize a spherical nano-Sb@C composite. Instrumental analyses reveal that the micro-nanostructured composite with an optimized Sb content of 68.8 wt% is composed of ...An aerosol spray pyrolysis technique is used to synthesize a spherical nano-Sb@C composite. Instrumental analyses reveal that the micro-nanostructured composite with an optimized Sb content of 68.8 wt% is composed of ultra-small Sb nanoparticles （10 nm） uniformly embedded within a spherical porous C matrix （denoted as 10-Sb@C）. The content and size of Sb can be controlled by altering the concentration of the precursor. As an anode material of sodium-ion batteries, 10-Sb@C provides a discharge capacity of 435 mAh.g^-1 in the second cycle and 385 mAh.g^-1 （a capacity retention of 88.5%） after 500 cycles at 100 mAh.g^-1. In particular, the electrode exhibits an excellent rate capability （355, 324, and 270 mAh.g^-1 at 1,000, 2,000, and 4,000 mAh.g^-1, respectively）. Such a high-rate performance for the Sb-C anode has rarely been reported. The remarkable electrochemical behavior of 10-Sb@C is attributed to the synergetic effects of ultra-small Sb nanoparticles with an uniform distribution and a porous C framework, which can effectively alleviate the stress associated with a large volume change and suppress the agglomeration of the pulverized nanoparticles during prolonged charge-discharge cycling.展开更多
文摘The oxidation states of Ge nanoparticles in the surface layer of Ge/Si film were studied by X-ray photoelectron spectroscopy. New features appeared at the high binding energy side of the XPS Ge 3d peak when samples were annealed in atmosphere, which were caused by the large interfacial area between the Ge and Si nanoparticles, as well as by the change in environment of the Ge nanoparticles and the oxidation states of Ge and Si.
基金This work was supported by the National Basic Research Program of China （973 Program） （No. 2011CB935900）, the National Natural Science Foundation of China （NSFC） （No. 51231003）, MOE （Nos. B12015 and IRT13R30）, and the Fundamental Research Funds for the Central Universities.
文摘An aerosol spray pyrolysis technique is used to synthesize a spherical nano-Sb@C composite. Instrumental analyses reveal that the micro-nanostructured composite with an optimized Sb content of 68.8 wt% is composed of ultra-small Sb nanoparticles （10 nm） uniformly embedded within a spherical porous C matrix （denoted as 10-Sb@C）. The content and size of Sb can be controlled by altering the concentration of the precursor. As an anode material of sodium-ion batteries, 10-Sb@C provides a discharge capacity of 435 mAh.g^-1 in the second cycle and 385 mAh.g^-1 （a capacity retention of 88.5%） after 500 cycles at 100 mAh.g^-1. In particular, the electrode exhibits an excellent rate capability （355, 324, and 270 mAh.g^-1 at 1,000, 2,000, and 4,000 mAh.g^-1, respectively）. Such a high-rate performance for the Sb-C anode has rarely been reported. The remarkable electrochemical behavior of 10-Sb@C is attributed to the synergetic effects of ultra-small Sb nanoparticles with an uniform distribution and a porous C framework, which can effectively alleviate the stress associated with a large volume change and suppress the agglomeration of the pulverized nanoparticles during prolonged charge-discharge cycling.
