Mn3O4-石墨烯气凝胶的高效制备及其储锂性能

Highly efficient formation of Mn3O4-graphene oxide hybrid aerogels for use as the cathode material of high performance lithium ion batteries

  • 摘要: 以改进的Hummers法制备的Mn2+/氧化石墨烯悬浊液为原料,无需添加锰源,采用水热法得到Mn3O4含量可调的Mn3O4-石墨烯气凝胶(Mn3O4-GA)。得益于石墨烯气凝胶相互连通的三维导电网络以及Mn3O4纳米粒子和其间的强烈的耦合作用,Mn3O4-GA表现出了比Mn3O4-石墨烯粉末复合物(Mn3O4-G)更加优异的储锂性能,其中Mn3O4-GA-70(Mn3O4含量为70%)在100 mA·g-1的电流密度下其可逆比容量达到1 073 mA·h·g-1,在800 mA·g-1的电流密度下循环200次后其比容量为565 mA·h·g-1,保持率为85%。该方法为环境友好制备锰基石墨烯气凝胶提供新思路。

     

    Abstract: We report a combined hydrothermal treatment and freeze-drying method to fabricate Mn3O4-graphene oxide (GO) hybrid aerogels for use as the cathode material of lithium ion batteries. Results indicate that the Mn3O4-GO hybrids show much better lithium storage capacity and rate capability than Mn3O4/reduced GO powder obtained by calcination of the hydrothermally treated sample dried at 300 ℃ for 30 min under an argon atmosphere. The stronger interaction between GO and Mn3O4 compared with that between reduced GO and Mn3O4 is beneficial for the improvement of utilization rate of Mn3O4 and therefore the capacity. Also the higher porosity of the Mn3O4-GO hybrids than that of the Mn3O4/reduced GO allows faster ion diffusion and therefore a higher rate capability. A typical Mn3O4-GO hybrid with a Mn3O4 content of 70 wt.% exhibits the highest specific capacity of 1 073 mA h g-1 at 100 mA g-1 and excellent cycling stability with a capacity retention rate of 85% of after 200 cycles at 800 mA g-1. The method is promising for the large-scale, environmentally friendly production of MnOx-GO hybrids for lithium ion batteries.

     

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