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

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 MnO_x-GO hybrids for lithium ion batteries.