以MnSO_4·H_2O和(NH_4)_2C_2O_4·H_2O为原料,葡萄糖为碳源,通过T形微反应器用直接沉淀法合成多孔碳(C)包覆一氧化锰(MnO)复合材料,并研究陈化时间对材料结构、形貌及电化学性能的影响。随着陈化时间的延长,前驱体及MnO/C由棒...以MnSO_4·H_2O和(NH_4)_2C_2O_4·H_2O为原料,葡萄糖为碳源,通过T形微反应器用直接沉淀法合成多孔碳(C)包覆一氧化锰(MnO)复合材料,并研究陈化时间对材料结构、形貌及电化学性能的影响。随着陈化时间的延长,前驱体及MnO/C由棒状演变为团聚块状体,前驱体及MnO/C材料的结晶度增加,MnO/C的比表面积减小,电化学性能变差。陈化时间为0时,合成的MnO/C以2 C在0.01~3.00 V循环100次,放电比容量为844 m Ah/g,5 C放电比容量为699 m Ah/g。展开更多
A strategy was developed to fabricate a set of MnO@C nanohybrids with MnO nanopartides （NPs） embedded in an ultrathin three-dimensional （3D） carbon framework for use as anode materials for lithium-ion batteries （...A strategy was developed to fabricate a set of MnO@C nanohybrids with MnO nanopartides （NPs） embedded in an ultrathin three-dimensional （3D） carbon framework for use as anode materials for lithium-ion batteries （LIBs）. The 3D carbon frameworks provide MnO NPs with electrical pathways and mechanical robustness, which efficiently improved the reaction kinetics, prevented the MnO from fracturing and agglomerating, and limited the formation of a solid electrolyte interface （SEI） at the MnO-electrolyte interface. Benefitting from the unique 3D framework structure, the MnO/C nanohybrids carbonized at 500 ℃ exhibited a highly reversible specific capacity of 1,420 mAh.g-1 at 0.2 A.g-1, excellent cycling stability with 98% capacity retention, and enhanced rate performance of 680 mAh-g-1 at 2 A.g-L The feasibility of the large-scale production of such MnO/C nanohybrids, associated with their outstanding Li-ion storage properties, opens a promising avenue for the development of high-performance anodes for next- generation LIBs.展开更多
转换型阳极材料因较高的比容量在储锂方面具有较大的应用潜力,但是严重的体积膨胀和低电导率限制了此类电极材料的倍率和循环性能.本研究设计了一种双金属锌锰基金属有机骨架(ZnMn-MOF)材料,并成功地将其转化成多孔炭封装的MnO颗粒(MnO/...转换型阳极材料因较高的比容量在储锂方面具有较大的应用潜力,但是严重的体积膨胀和低电导率限制了此类电极材料的倍率和循环性能.本研究设计了一种双金属锌锰基金属有机骨架(ZnMn-MOF)材料,并成功地将其转化成多孔炭封装的MnO颗粒(MnO/PC)复合电极材料.配位锌组元的模板和活化作用赋予PC基体多孔结构,能够显著地提高PC基体与MnO颗粒的相容性,导致MnO颗粒完全封装于PC基体中.更重要的是,PC基体的多孔结构为缓冲MnO的体积变化提供了足够的空间,经过反复的充放电循环后MnO仍完全封装于PC基体而不发生破裂乃至破碎.研究结果表明,MnO/PC同时具有较高的电荷储存容量、优异的倍率性能和超长的循环稳定性.MnO/PC在0.1 A g^(-1)时具有768 mA h g^(-1)的比容量,在0.7 A g^(-1)时其比容量仍能保持487 mA h g^(-1),并且在0.3 A g^(-1)循环500次后性能未衰减.值得关注的是,MnO/PC在锂离子电容器中与电容型活性炭电极表现出良好的匹配性,组装的锂离子电容器在比功率为210Wkg^(-1)时实现了153.6Wh kg^(-1)的比能量,并且在比功率为63.0kW kg^(-1)时仍能维持71.8W h kg^(-1)的比能量.展开更多
文摘以MnSO_4·H_2O和(NH_4)_2C_2O_4·H_2O为原料,葡萄糖为碳源,通过T形微反应器用直接沉淀法合成多孔碳(C)包覆一氧化锰(MnO)复合材料,并研究陈化时间对材料结构、形貌及电化学性能的影响。随着陈化时间的延长,前驱体及MnO/C由棒状演变为团聚块状体,前驱体及MnO/C材料的结晶度增加,MnO/C的比表面积减小,电化学性能变差。陈化时间为0时,合成的MnO/C以2 C在0.01~3.00 V循环100次,放电比容量为844 m Ah/g,5 C放电比容量为699 m Ah/g。
文摘A strategy was developed to fabricate a set of MnO@C nanohybrids with MnO nanopartides （NPs） embedded in an ultrathin three-dimensional （3D） carbon framework for use as anode materials for lithium-ion batteries （LIBs）. The 3D carbon frameworks provide MnO NPs with electrical pathways and mechanical robustness, which efficiently improved the reaction kinetics, prevented the MnO from fracturing and agglomerating, and limited the formation of a solid electrolyte interface （SEI） at the MnO-electrolyte interface. Benefitting from the unique 3D framework structure, the MnO/C nanohybrids carbonized at 500 ℃ exhibited a highly reversible specific capacity of 1,420 mAh.g-1 at 0.2 A.g-1, excellent cycling stability with 98% capacity retention, and enhanced rate performance of 680 mAh-g-1 at 2 A.g-L The feasibility of the large-scale production of such MnO/C nanohybrids, associated with their outstanding Li-ion storage properties, opens a promising avenue for the development of high-performance anodes for next- generation LIBs.
基金supported by the National Natural Science Foundation of China(21905148)China Postdoctoral Science Foundation(2019T120567 and 2017M612184)+2 种基金the 1000-Talents Planthe World-Class Discipline Programthe Taishan Scholars Advantageous and Distinctive Discipline Program of Shandong province for supporting the research team of energy storage materials.
文摘转换型阳极材料因较高的比容量在储锂方面具有较大的应用潜力,但是严重的体积膨胀和低电导率限制了此类电极材料的倍率和循环性能.本研究设计了一种双金属锌锰基金属有机骨架(ZnMn-MOF)材料,并成功地将其转化成多孔炭封装的MnO颗粒(MnO/PC)复合电极材料.配位锌组元的模板和活化作用赋予PC基体多孔结构,能够显著地提高PC基体与MnO颗粒的相容性,导致MnO颗粒完全封装于PC基体中.更重要的是,PC基体的多孔结构为缓冲MnO的体积变化提供了足够的空间,经过反复的充放电循环后MnO仍完全封装于PC基体而不发生破裂乃至破碎.研究结果表明,MnO/PC同时具有较高的电荷储存容量、优异的倍率性能和超长的循环稳定性.MnO/PC在0.1 A g^(-1)时具有768 mA h g^(-1)的比容量,在0.7 A g^(-1)时其比容量仍能保持487 mA h g^(-1),并且在0.3 A g^(-1)循环500次后性能未衰减.值得关注的是,MnO/PC在锂离子电容器中与电容型活性炭电极表现出良好的匹配性,组装的锂离子电容器在比功率为210Wkg^(-1)时实现了153.6Wh kg^(-1)的比能量,并且在比功率为63.0kW kg^(-1)时仍能维持71.8W h kg^(-1)的比能量.
