多级次孔结构ZnMn2O4微球负极的研究

Hierarchical porous ZnMn2O4 microsphere anode

利用水热法合成了Zn-Mn氧化物前驱体,在温度400、500、600、700℃下,空气气氛中煅烧前驱体,以此来制备纳米片组装成的分级多孔结构的ZnMn2O4微球。其中,在500℃空气中煅烧前驱体制备的ZnMn2O4(ZMO-500)微球具有丰富的多级次孔结构,其作为锂离子电池负极材料,在500 mA/g的电流密度下,ZMO-500微球负极材料循环500次以后仍具有1132 mAh/g高的放电比容量。ZMO-500负极材料优异的电化学性能得益于其分级多孔结构,不仅可以增加电极和电解质之间的接触面积以促进锂离子的迁移,而且还为循环过程中电极体积膨胀提供足够的缓冲空间。

The precursor of Zn-Mn oxides were synthesized by a facile hydrothermal method and subsequently calcined at different temperature of 400℃,500℃,600℃and 700℃in air in order to synthesis the hierarchical porous ZnMn2O4 microspheres assembled by a lot of nanosheets.The ZnMn2O4 microspheres synthesized by calcining precursor in air at 500℃(ZMO-500)display rich hierarchical porous structures,and when used as the anode material of lithium ion batteries,ZMO-500 microsphere anode material exhibits a high discharge capacity of 1132 mAh/g after 500 cycles at a current density of 500 mA/g.It is believed that the outstanding electrochemical performance of ZMO-500 microsphere anode material benefits from the hierarchical porous structure that can not only increase the contact area between the electrode and the electrolyte to facilitate the transfer of Li+,but also provide sufficient space for volume expansion of the electrode during the cyclic process.