Graphite anode materials are widely used in commercial lithium-ion batteries;however, the long electron/ion transportation path restricted its high energy storage. In this experiment, we designed a copper/graphite com...Graphite anode materials are widely used in commercial lithium-ion batteries;however, the long electron/ion transportation path restricted its high energy storage. In this experiment, we designed a copper/graphite composite with a dual three-dimensional(3 D) continuous porous structure combining used nonsolvent-induced phase separation and heat treatment, in which a large amount of graphite is embedded in the 3 D porous copper/carbon architecture. In the novel structure, not only the electron and Li^(+) transmission performances are improved, but also the space of current collector is fully utilized. Meanwhile,carbonized polyacrylonitrile network stabilizes the interface between graphite and copper matrix. The obtained copper/graphite composite anode has an initial discharge capacity of 524.6 mAh·g^(-1), a holding capacity of350 mAh·g^(-1) and excellent cycle stability(299.3 mAh·g^(-1) after 180 cycles at 0.1 C rate), exhibiting good electrochemical performance. The experimental results show that the mass loading of the copper/graphite composite electrode material is about 4.39 mg·cm^(-2). We also envisage replacing graphite with other high-capacity active materials to fill the current collector, which can provide a reference for the future development of next-generation advanced electrodes.展开更多
采用液相法制备铜纳米棒阵列,并用作锂离子电池负极集流体,通过电沉积制备Sn-Co-Zn纳米棒阵列合金电极。合金电极主要是由Co Sn、Co Sn2和单质Zn组成的混晶。以1 C在0.02~1.50 V循环,合金电极首次循环的放电比容量为813.8 m Ah/g,库仑...采用液相法制备铜纳米棒阵列,并用作锂离子电池负极集流体,通过电沉积制备Sn-Co-Zn纳米棒阵列合金电极。合金电极主要是由Co Sn、Co Sn2和单质Zn组成的混晶。以1 C在0.02~1.50 V循环,合金电极首次循环的放电比容量为813.8 m Ah/g,库仑效率为87.5%,第50次循环的放电比容量为467.0 m Ah/g。电极活性材料多相结构及纳米阵列间隙,可缓解嵌锂过程中的体积膨胀。展开更多
锂金属因其具有超高比容量(3860 mAh·g^(-1))以及较低的氧化还原电势(-3.04 V vs标准氢电极),被认为是下一代高能量密度二次电池的理想负极材料。然而“无宿主”的金属锂在金属/电解液界面层进行沉积/剥离,不可避免地会生长枝晶,...锂金属因其具有超高比容量(3860 mAh·g^(-1))以及较低的氧化还原电势(-3.04 V vs标准氢电极),被认为是下一代高能量密度二次电池的理想负极材料。然而“无宿主”的金属锂在金属/电解液界面层进行沉积/剥离,不可避免地会生长枝晶,不仅使电极表面电流分布不均,同时可能会刺穿电池隔膜而导致电池短路。通过构造三维集流体/锂金属复合负极可以有效调控锂沉积行为并抑制枝晶生长,从而提升电池的库仑效率、循环寿命以及倍率性能,该领域近年来一直都是研究的热点。本文首先总结了基于三维集流体抑制锂枝晶的相关原理和模型;其次针对用于负极的铜基集流体,根据构成三维结构基底单元的维度,总结了三维铜基集流体的制备方法及其在锂金属负极保护方面的应用;最后,对三维集流体构造复合锂负极进行了总结和展望。展开更多
基金financially supported by Tianjin Municipal Education Committee Scientific Research Project (No.2017KJ075)。
文摘Graphite anode materials are widely used in commercial lithium-ion batteries;however, the long electron/ion transportation path restricted its high energy storage. In this experiment, we designed a copper/graphite composite with a dual three-dimensional(3 D) continuous porous structure combining used nonsolvent-induced phase separation and heat treatment, in which a large amount of graphite is embedded in the 3 D porous copper/carbon architecture. In the novel structure, not only the electron and Li^(+) transmission performances are improved, but also the space of current collector is fully utilized. Meanwhile,carbonized polyacrylonitrile network stabilizes the interface between graphite and copper matrix. The obtained copper/graphite composite anode has an initial discharge capacity of 524.6 mAh·g^(-1), a holding capacity of350 mAh·g^(-1) and excellent cycle stability(299.3 mAh·g^(-1) after 180 cycles at 0.1 C rate), exhibiting good electrochemical performance. The experimental results show that the mass loading of the copper/graphite composite electrode material is about 4.39 mg·cm^(-2). We also envisage replacing graphite with other high-capacity active materials to fill the current collector, which can provide a reference for the future development of next-generation advanced electrodes.
文摘采用液相法制备铜纳米棒阵列,并用作锂离子电池负极集流体,通过电沉积制备Sn-Co-Zn纳米棒阵列合金电极。合金电极主要是由Co Sn、Co Sn2和单质Zn组成的混晶。以1 C在0.02~1.50 V循环,合金电极首次循环的放电比容量为813.8 m Ah/g,库仑效率为87.5%,第50次循环的放电比容量为467.0 m Ah/g。电极活性材料多相结构及纳米阵列间隙,可缓解嵌锂过程中的体积膨胀。
文摘锂金属因其具有超高比容量(3860 mAh·g^(-1))以及较低的氧化还原电势(-3.04 V vs标准氢电极),被认为是下一代高能量密度二次电池的理想负极材料。然而“无宿主”的金属锂在金属/电解液界面层进行沉积/剥离,不可避免地会生长枝晶,不仅使电极表面电流分布不均,同时可能会刺穿电池隔膜而导致电池短路。通过构造三维集流体/锂金属复合负极可以有效调控锂沉积行为并抑制枝晶生长,从而提升电池的库仑效率、循环寿命以及倍率性能,该领域近年来一直都是研究的热点。本文首先总结了基于三维集流体抑制锂枝晶的相关原理和模型;其次针对用于负极的铜基集流体,根据构成三维结构基底单元的维度,总结了三维铜基集流体的制备方法及其在锂金属负极保护方面的应用;最后,对三维集流体构造复合锂负极进行了总结和展望。
