MnFe2O4-graphene nanocomposites with enhanced performances as anode materials for Li-ion batteries
MnFe2O4-graphene nanocomposites with enhanced performances as anode materials for Li-ion batteries
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MnFe2O4-石墨烯纳米复合材料作为锂离子电池负极材料的性能增强
DOI：
10.1039/c3cp50220a
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Qian, Xuefeng
中科院分区：
文献类型：
--
作者：
Xiao, Yinglin;Zai, Jiantao;Qian, Xuefeng
通过超声法制备了电化学性能增强的mnfe2o4 -石墨烯纳米复合材料（MnFe2O4-GNSs），即在0.1 a g（-1）和1 a g（-1）的电流密度下，即使在90次循环后仍保持约1017 mA h g（-1）和767 mA h g（-1）的可逆容量。制备的MnFe2O4-GNSs纳米复合材料的可逆性能、循环稳定性和速率性能的显著提高可归因于石墨烯纳米片良好的导电性和特殊的结构。另一方面，在充放电过程中，MnFe2O4转化为粒径约为20 nm的纳米级Fe3O4-MnO杂化物，原位形成的Fe3O4-MnO杂化物可以与GNSs结合形成海绵状多孔结构，也发挥了重要作用。此外，形成的杂化物还可以作为MnO或Fe3O4的基体，防止Fe3O4或MnO的聚集，并在充放电过程中适应活性材料的体积变化，这也有利于提高MnFe2O4-GNSs纳米复合材料的电化学性能。
MnFe2O4-graphene nanocomposites (MnFe2O4-GNSs) with enhanced electrochemical performances have been successfully prepared through an ultrasonic method, e. g., approximate 1017 mA h g(-1) and 767 mA h g(-1) reversible capacities are retained even after 90 cycles at a current density of 0.1 A g(-1) and 1 A g(-1), respectively. The remarkable improvement in the reversible capacity, cyclic stability and rate capability of the obtained MnFe2O4-GNSs nanocomposites can be attributed to the good electrical conductivity and special structure of the graphene nanosheets. On the other hand, MnFe2O4 also plays an important role because it transforms into a nanosized hybrid of Fe3O4-MnO with a particle size of about 20 nm during discharge-charge process, and the in situ formed hybrid of Fe3O4-MnO can be combined with GNSs to form a spongy porous structure. Furthermore, the formed hybrid can also act as the matrix of MnO or Fe3O4 to prevent the aggregation of Fe3O4 or MnO, and accommodate the volume change of the active materials during the discharge-charge processes, which is also beneficial to improve the electrochemical performances of the MnFe2O4-GNSs nanocomposites.