锂离子电池用CoMoO4/炭颗粒与氮掺杂多孔炭复合材料

CoMoO4-N-doped carbon hybrid nanoparticles loaded on a petroleum asphalt-based porous carbon for lithium storage

  • 摘要: 超精细过渡金属氧化物(TMO)在储锂方面具有巨大潜力,但在实际应用中还存在易团聚、电导率低等挑战。本文采用双炭复合方法,首先将ZIFs-67固定于模板法制备的石油沥青基多孔炭骨架上,然后将配位Co2+原位转化为CoMoO4@炭纳米颗粒,生成CoMoO4@炭纳米颗粒/多孔炭骨架(CoMoO4@CP/CF)。通过ZIFs-67热解制备出N掺杂炭骨架,从本质上提高CoMoO4电子传输能力,而超细炭纳米颗粒可以有效阻止CoMoO4聚集。基于上述优点,将该复合材料用做锂离子电池负极,电流密度为1 A g-1时,可提供高达818 mAh g-1的可逆比容量。该合成方法为高性能储能电极材料的设计提供了新途径。

     

    Abstract: Ultrafine transition metal oxides have great potential for efficient lithium storage but some key problems, such as a strong tendency to aggregate and poor electrical conductivity, need to be solved for their possible application. Here, hybrid nanoparticles of CoMoO4 and N-doped carbon were formed in a petroleum asphalt-based porous carbon prepared by a template method. A Co-based zeolitic imidazolate framework (ZIF-67) was then synthesized in-situ in its pores from Co(NO3)2·6H2O and 2-methylimidazole. The porous carbon was impregnated with Na2MoO4·2H2O and polyvinyl pyrrolidone, followed by solvothermal treatment at 180℃ for 24 h and finally calcination to convert the loaded components into hybrid nanoparticles of CoMoO4 and N-doped carbon. Results indicate that the N-doped carbon boosts the electron transport ability of CoMoO4 and efficiently prevents its aggregation. At an optimal CoMoO4 loading the composite was used as an anode material in a lithium ion battery and delivered a reversible specific capacity of 818 mAh g-1 at 1 A g-1, an initial coulombic efficiency of around 70%, and outstanding cycle and structural stability during cycling. The strategy reported here may open up a new avenue for the rational design and construction of well-designed electrode materials for energy storage.

     

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