In the present study,the texture evolution and mechanical anisotropy in a typical Mg–Zn–Ca alloy through hot cross rolling(CR)and unidirectional rolling(UR)were systematically studied.The results show that the rolli...In the present study,the texture evolution and mechanical anisotropy in a typical Mg–Zn–Ca alloy through hot cross rolling(CR)and unidirectional rolling(UR)were systematically studied.The results show that the rolling path greatly affects the annealed texture.The UR develops a texture with basal poles mainly distributing along the transverse direction(TD).By contrast,an ellipse-like(0002)texture with basal pole inclining largely away from the normal direction(ND)is developed after hot cross rolling and annealing.Therefore,the CR is an effective method to tailor the texture of the experimental alloy.Unfortunately,this ellipse-like texture could not reserve during the subsequent unidirectional hot rolling and annealing.Both UR and CR plates exhibit a strong planar mechanical anisotropy compared with the traditional unidirectional rolled plate.展开更多
Direct integration of lithium-ion battery （LIB） with electronic devices on the same Si substrate can significantly miniaturize autonomous micro systems. For achieving direct integration, a barrier layer is essential...Direct integration of lithium-ion battery （LIB） with electronic devices on the same Si substrate can significantly miniaturize autonomous micro systems. For achieving direct integration, a barrier layer is essential to be inserted between LIB and the substrate for blocking Li^＋ diffusion. In this paper, the feasibility of thermal SiOa film as the barrier layer is investigated by electrochemical characterization and X-ray photoelectron spectroscopy （XPS）. Due to the negligible side reactions of thermal SiO2 with electrolyte, the solid electrolyte interphase （SEI） layer formed on the surface of the barrier layer is thin and the SEI content mainly consists of hydrocarbon together with slight polyethylene oxide （PEO）, LixPOyFz, and Li2CO3. Although 8-nm thermal SiO2 effectively prevents the substrate from alloying with Li^＋, the whole film changes to Li silicate after electrochemical cycling due to the irreversible chemical reactions of SiO2 with electrolyte. This degrades the performance of the barrier layer against the electrolyte penetration, thus leading to the existence of Li^＋ （in the form of F-Si-Li） and solvent decompositions （with the products of hydrocarbon and PEO） near the barrier layer/substrate interface. Moreover, it is found that the reaction kinetics of thermal SiO2 with electrolyte decrease significantly with increasing the SiO2 thickness and no reactions are found in the bulk of the 30-nm SiO2 film. Therefore, thermal SiO2 with an appropriate thickness is a promising barrier layer for direct integration.展开更多
基金the National Key Basic Research Program of China(2013CB632204)Natural Science Foundation of China(51671040).
文摘In the present study,the texture evolution and mechanical anisotropy in a typical Mg–Zn–Ca alloy through hot cross rolling(CR)and unidirectional rolling(UR)were systematically studied.The results show that the rolling path greatly affects the annealed texture.The UR develops a texture with basal poles mainly distributing along the transverse direction(TD).By contrast,an ellipse-like(0002)texture with basal pole inclining largely away from the normal direction(ND)is developed after hot cross rolling and annealing.Therefore,the CR is an effective method to tailor the texture of the experimental alloy.Unfortunately,this ellipse-like texture could not reserve during the subsequent unidirectional hot rolling and annealing.Both UR and CR plates exhibit a strong planar mechanical anisotropy compared with the traditional unidirectional rolled plate.
基金This work was supported by the Natural Science Foundation of Jiangsu Province （Grant No. BK20140639） and the National Natural Science Foundation of China （Grant No. 21206070）.
文摘Direct integration of lithium-ion battery （LIB） with electronic devices on the same Si substrate can significantly miniaturize autonomous micro systems. For achieving direct integration, a barrier layer is essential to be inserted between LIB and the substrate for blocking Li^＋ diffusion. In this paper, the feasibility of thermal SiOa film as the barrier layer is investigated by electrochemical characterization and X-ray photoelectron spectroscopy （XPS）. Due to the negligible side reactions of thermal SiO2 with electrolyte, the solid electrolyte interphase （SEI） layer formed on the surface of the barrier layer is thin and the SEI content mainly consists of hydrocarbon together with slight polyethylene oxide （PEO）, LixPOyFz, and Li2CO3. Although 8-nm thermal SiO2 effectively prevents the substrate from alloying with Li^＋, the whole film changes to Li silicate after electrochemical cycling due to the irreversible chemical reactions of SiO2 with electrolyte. This degrades the performance of the barrier layer against the electrolyte penetration, thus leading to the existence of Li^＋ （in the form of F-Si-Li） and solvent decompositions （with the products of hydrocarbon and PEO） near the barrier layer/substrate interface. Moreover, it is found that the reaction kinetics of thermal SiO2 with electrolyte decrease significantly with increasing the SiO2 thickness and no reactions are found in the bulk of the 30-nm SiO2 film. Therefore, thermal SiO2 with an appropriate thickness is a promising barrier layer for direct integration.
