MnO/C/Sepiolite 3D-network aerogel as electrode material for supercapacitors

With the gradual increase of people's demand for energy, the energy crisis is becoming increasingly severe. A new and efficient energy storage device must be urgently exploited to relieve the pressure brought by the energy crisis. In this paper, MnO/C/Sepiolite aerogel nanocomposites were prepared by supercritical technology and freeze-drying technology as electrode materials for supercapacitors. The morphology of MnO/C aerogel is granular nanospheres, and the particle size of the calcined MnO/C aerogel ranges from 80 nm to 100 nm. Sepiolite with the unique fibrous structure can provide a matrix for MnO/C aerogel to form a stable 3D-network aerogel, and then lead to more active sites to be exposed. As results, the specific capacity of MnO/C/Sepiolite aerogel can reach 103.9 mAh/g, while the specific capacity of MnO/C aerogel is only 55.7 mAh/g at the current density of 1 A/g. Furthermore, the specific capacitance of MnO/C/Sepiolite aerogel can reach 507.4 F/g at the scan rate of 5 mV/s, higher than that of MnO/C aerogel (365.8 F/g). After 1400 cycles of repetitive charge/ discharge measurement at 20 A/g current density, it is find that the specific capacitance retention rate of MnO/ C/Sepiolite aerogel (98.57% retention) is higher than that of MnO/C aerogel (95.71% retention). Therefore, the problems of particle agglomeration of MnO/C active substances and low degree of active site exposure were effectively improved by the introduction of sepiolite.

Automated summary

With the increasing demand for energy, the energy crisis is becoming more severe. In this study, MnO/C/Sepiolite aerogel nanocomposites were prepared as electrode materials for supercapacitors, which exhibited higher specific capacity and capacitance compared to MnO/C aerogel. The introduction of sepiolite effectively improved the problems of particle agglomeration and low active site exposure of MnO/C active substances.