Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercia...Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.展开更多
Up to now, the Pedgion magnesium reduction process is the dominating magnesium production process. In 2004, about 98% of raw magnesium is produced by Pedgion magnesium reduction process in China which equals to 60% of...Up to now, the Pedgion magnesium reduction process is the dominating magnesium production process. In 2004, about 98% of raw magnesium is produced by Pedgion magnesium reduction process in China which equals to 60% of the global output. It shows that the dolomite-ferrosilicon thermal reduction process is the most important method to produce magnesium in the world. Limited by the disadvantage of dolomite-ferrosilicon thermal reduction process, the magnesium producing process always followed by relatively severe pollution, while the resource utilizing efficiency keeps very low. With the rapid development of dolomite-ferrosilicon thermal reduction process in China, many research works have been done aiming at the process technology and the reduction theory, and the magnesium producing process has got great evolution. The history of dolomite-ferrosilicon thermal reduction process was introduced; the process character, the merits and which defects were also discussed. Defects in dolomite-ferrosilicon thermal reduction process were expatiated, and feasible method and idea to upgrade the process was put forward. The main problems and the potential troubles hindering the development of magnesium industry were analyzed. Finally, the probability to further improve the thermal reduction process and the effective approaches to develop Chinese magnesium industry were discussed.展开更多
To obtain solid Al2O3 or MgO·Al2O3 inclusions in ladle furnace(LF)refining process and achieve ultra-low total oxygen content in steel through subsequent Ruhrstahl Heraeus degassing,the effects of ferrosilicon al...To obtain solid Al2O3 or MgO·Al2O3 inclusions in ladle furnace(LF)refining process and achieve ultra-low total oxygen content in steel through subsequent Ruhrstahl Heraeus degassing,the effects of ferrosilicon alloy,Si content of steel,and slag basicity on the compositions of inclusions during LF refining were investigated in Al-killed steel.Al2O3 inclusions could be transformed into CaO-Al2O3-MgO-CaS inclusions after adding ferrosilicon alloy in the LF refining process as this alloy contains some CaSi alloy impurities.The addition of all ferrosilicon alloys required for the steel in the tapping process could eliminate the influence of Ca in ferrosilicon alloy on the compositions of inclusions.Si in liquid steel had a significant influence on the compositions of inclusions during LF refining when CaO-Al2O3-SiO2-MgO slag with high basicity of 7.0 was used.This was because[Ca]produced by the reaction of CaO and[Al]could be consumed more readily by SiO2 in Si-free steel than in Si-containing steel,which was confirmed by the difference of total calcium content between Si-free and Si-containing steels.As a result,Al2O3 and MgO·Al2O3 inclusions were retained in Si-free steel,whereas calcium aluminate inclusions were found in Si-containing steel.For CaO-Al2O3-SiO2-MgO slag with low basicity of 2.8,Al2O3 and MgO·Al2O3 inclusions were obtained after LF refining in Si-containing steel when all ferrosilicon alloys required for the steel were added in the tapping process.This was because the reaction of CaO and[Al]was weak,and residual[Ca]in the steel could be rapidly consumed by SiO2 in low-basicity slag owing to the low activity of CaO and high activity of SiO2,leading to a low total calcium content of 0.0003%in Si-containing steel.展开更多
基金the National Natural Science Foundation of China(No:21703285)。
文摘Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.
文摘Up to now, the Pedgion magnesium reduction process is the dominating magnesium production process. In 2004, about 98% of raw magnesium is produced by Pedgion magnesium reduction process in China which equals to 60% of the global output. It shows that the dolomite-ferrosilicon thermal reduction process is the most important method to produce magnesium in the world. Limited by the disadvantage of dolomite-ferrosilicon thermal reduction process, the magnesium producing process always followed by relatively severe pollution, while the resource utilizing efficiency keeps very low. With the rapid development of dolomite-ferrosilicon thermal reduction process in China, many research works have been done aiming at the process technology and the reduction theory, and the magnesium producing process has got great evolution. The history of dolomite-ferrosilicon thermal reduction process was introduced; the process character, the merits and which defects were also discussed. Defects in dolomite-ferrosilicon thermal reduction process were expatiated, and feasible method and idea to upgrade the process was put forward. The main problems and the potential troubles hindering the development of magnesium industry were analyzed. Finally, the probability to further improve the thermal reduction process and the effective approaches to develop Chinese magnesium industry were discussed.
文摘To obtain solid Al2O3 or MgO·Al2O3 inclusions in ladle furnace(LF)refining process and achieve ultra-low total oxygen content in steel through subsequent Ruhrstahl Heraeus degassing,the effects of ferrosilicon alloy,Si content of steel,and slag basicity on the compositions of inclusions during LF refining were investigated in Al-killed steel.Al2O3 inclusions could be transformed into CaO-Al2O3-MgO-CaS inclusions after adding ferrosilicon alloy in the LF refining process as this alloy contains some CaSi alloy impurities.The addition of all ferrosilicon alloys required for the steel in the tapping process could eliminate the influence of Ca in ferrosilicon alloy on the compositions of inclusions.Si in liquid steel had a significant influence on the compositions of inclusions during LF refining when CaO-Al2O3-SiO2-MgO slag with high basicity of 7.0 was used.This was because[Ca]produced by the reaction of CaO and[Al]could be consumed more readily by SiO2 in Si-free steel than in Si-containing steel,which was confirmed by the difference of total calcium content between Si-free and Si-containing steels.As a result,Al2O3 and MgO·Al2O3 inclusions were retained in Si-free steel,whereas calcium aluminate inclusions were found in Si-containing steel.For CaO-Al2O3-SiO2-MgO slag with low basicity of 2.8,Al2O3 and MgO·Al2O3 inclusions were obtained after LF refining in Si-containing steel when all ferrosilicon alloys required for the steel were added in the tapping process.This was because the reaction of CaO and[Al]was weak,and residual[Ca]in the steel could be rapidly consumed by SiO2 in low-basicity slag owing to the low activity of CaO and high activity of SiO2,leading to a low total calcium content of 0.0003%in Si-containing steel.
