Silicon monoxide(SiO)has aroused increased attention as one of the most promising anodes for high-energy density Li-ion batteries.To enhance the initial Coulombic efficiencies(ICE)and cycle stability of SiO-based anod...Silicon monoxide(SiO)has aroused increased attention as one of the most promising anodes for high-energy density Li-ion batteries.To enhance the initial Coulombic efficiencies(ICE)and cycle stability of SiO-based anodes,a new facile composition and electrode design strategy have been adapted to fabricate a SiO-Sn-Co/graphite(G)anode.It achieves a unique structure where tiny milled SiO-Sn-Co particles are dispersed among two graphite layers.In this hybrid electrode,Sn-Co alloys promoted Li;extraction kinetics,and the holistic reversibility of SiO and graphite enhanced the electrical conductivity.The SiO-Sn-Co/G electrode delivered an average ICE of 77.6%and a reversible capacity of 640 mAh g^(-1)at 800 mA g^(-1),and the capacity retention was above 98%after 100 cycles,which was much higher than that of the SiO with an ICE of 55.3%and a capacity retention of 50%.These results indicated that this was reliable method to improve the reversibility and cycle ability of the SiO anode.Furthermore,based on its easy and feasible fabrication process,it may provide a suitable choice to combine other alloy anodes with the graphite anode.展开更多
为改善锂离子电池硅负极材料的电化学性能,利用镁热还原法制备了不同铁掺杂量的多孔硅/硅铁合金复合材料,并对其结构以及在锂离子电池中的充放电性能进行了研究.材料均呈现多孔结构,硅铁合金均匀分布在孔道内部.多孔硅/硅铁合金复合材...为改善锂离子电池硅负极材料的电化学性能,利用镁热还原法制备了不同铁掺杂量的多孔硅/硅铁合金复合材料,并对其结构以及在锂离子电池中的充放电性能进行了研究.材料均呈现多孔结构,硅铁合金均匀分布在孔道内部.多孔硅/硅铁合金复合材料具有较好的循环稳定性,在0.1C倍率下循环100圈后可逆容量为1 133.5 m A·h/g,容量保持率为66%;在1C倍率下可逆容量仍可以达到776.9 m A·h/g.展开更多
分别制备硫碳比为6∶4、7∶3、8∶2、9∶1的Li-S电池正极材料。采用XRD分析了这4种正极材料的成分结构,用场发射扫描电子显微镜观察了它们的形貌,利用交流阻抗谱、循环伏安和电池充放电测试电池的电化学性能。结果表明:正极材料S∶C=8∶...分别制备硫碳比为6∶4、7∶3、8∶2、9∶1的Li-S电池正极材料。采用XRD分析了这4种正极材料的成分结构,用场发射扫描电子显微镜观察了它们的形貌,利用交流阻抗谱、循环伏安和电池充放电测试电池的电化学性能。结果表明:正极材料S∶C=8∶2时,电池在0.2 C放电倍率下,首次放电容量为1299 m Ah/g,100次循环后仍能保持570 m Ah/g左右,经过20次循环后电池的库仑效率仍稳定在99%左右,性能明显优于其他3种正极材料组成的电池。展开更多
基金supported by the National Natural Science Foundation of China (No. 52071144, 51822104, 51831009, and 51621001)
文摘Silicon monoxide(SiO)has aroused increased attention as one of the most promising anodes for high-energy density Li-ion batteries.To enhance the initial Coulombic efficiencies(ICE)and cycle stability of SiO-based anodes,a new facile composition and electrode design strategy have been adapted to fabricate a SiO-Sn-Co/graphite(G)anode.It achieves a unique structure where tiny milled SiO-Sn-Co particles are dispersed among two graphite layers.In this hybrid electrode,Sn-Co alloys promoted Li;extraction kinetics,and the holistic reversibility of SiO and graphite enhanced the electrical conductivity.The SiO-Sn-Co/G electrode delivered an average ICE of 77.6%and a reversible capacity of 640 mAh g^(-1)at 800 mA g^(-1),and the capacity retention was above 98%after 100 cycles,which was much higher than that of the SiO with an ICE of 55.3%and a capacity retention of 50%.These results indicated that this was reliable method to improve the reversibility and cycle ability of the SiO anode.Furthermore,based on its easy and feasible fabrication process,it may provide a suitable choice to combine other alloy anodes with the graphite anode.
文摘为改善锂离子电池硅负极材料的电化学性能,利用镁热还原法制备了不同铁掺杂量的多孔硅/硅铁合金复合材料,并对其结构以及在锂离子电池中的充放电性能进行了研究.材料均呈现多孔结构,硅铁合金均匀分布在孔道内部.多孔硅/硅铁合金复合材料具有较好的循环稳定性,在0.1C倍率下循环100圈后可逆容量为1 133.5 m A·h/g,容量保持率为66%;在1C倍率下可逆容量仍可以达到776.9 m A·h/g.
文摘分别制备硫碳比为6∶4、7∶3、8∶2、9∶1的Li-S电池正极材料。采用XRD分析了这4种正极材料的成分结构,用场发射扫描电子显微镜观察了它们的形貌,利用交流阻抗谱、循环伏安和电池充放电测试电池的电化学性能。结果表明:正极材料S∶C=8∶2时,电池在0.2 C放电倍率下,首次放电容量为1299 m Ah/g,100次循环后仍能保持570 m Ah/g左右,经过20次循环后电池的库仑效率仍稳定在99%左右,性能明显优于其他3种正极材料组成的电池。
