Salt-template assisted preparation and electrochemical performance of MnO/C nanosheet composite electrode for lithium-ion battery

Abstract

MnO/C nanosheet composites have been prepared by heating NaCl@Mn(Oleate)2 particles at 600 °C with a heating rate of 10 °C min−1 under Ar atmosphere for 3 h, and NaCl@Mn(Oleate)2 particles are obtained by coating NaCl powder with the solution of Mn(Oleate)2/n-hexane. The effects of NaCl amount, heating temperatures and heating rates on the grain size and dispersity of MnO crystals are systematically investigated, respectively. The results show that NaCl plays an important role in providing the surface to fabricate the MnO/C nanosheet composites. The thickness of MnO/C nanosheet is influenced by the amount of NaCl, and its optimal amount is 7.5 g as the weight ratio of 12.146 to Mn(Oleate)2. The dimension and morphology of the MnO nanocrystals embedded on the carbon nanosheets are affected by the heating rates and heating temperatures of NaCl@Mn(Oleate)2 particles as well. On the other hand, the conductivity of the obtained composites is well improved during the lithiation/delithiation processes. Meanwhile, the aggregation of MnO nanoparticles is effectively mitigated by the construction of carbon network structure. MnO/C nanosheet composite electrodes exhibit a high reversible capacity of 783 mAh g−1 in the second cycle at a current density of 0.1 A g−1, excellent cycling stability with a capacity retention of 71.7% and good rate performance as the anode in lithium ion battery. The synthetic procedure in the present study could be extended to prepare other metal oxide/carbon nanosheet composites for energy storage materials.