Facile synthesis and simulation of MnO2 nanoflakes on vertically aligned carbon nanotubes, as a high-performance electrode for Li-ion battery and supercapacitor

This study reports the successful fabrication of high-performance flexible binder-free lithium-ion battery anode and supercapacitor based on the synthesis of 3D hierarchical MnO 2 nanoflakes (NFs) on vertically aligned carbon nanotubes (VACNTs) grown upon stainless steel (SS). The experimental results revealed that the prepared electrodes were well served as supercapacitors with a tremendous specific capacitance of MnO 2 NFs VACNT/SS 1131 F/g at 0.25 A/g in 0.5 mol.L −1 Na 2 SO 4 , 518.8% more than VACNT/SS (218 F/g). Compared to other MnO 2 NFs/CNT composites, as-fabricated binder-free MnO 2 NFs/VACNTs electrode achieves outstanding performance with high initial discharge and charge capacities of 2438 and 1289 mAhg −1 at a current density of 250 mAg −1 , respectively. The fabricated anode anode further demonstrates an extraordinarily high reversible capacity of 803.2 mAhg −1 with columbic efficiency of 98.4% at a current density of 250 mAg −1 over 150 charge/discharge runs. Compared to pure VACNTs electrode, the MnO 2 /VACNTs has significantly improved cycling stability and lithium storage capability, making this nanocomposite a promising anode for LIBs. Meanwhile, the electrochemical behavior of MnO 2 NFs/VACNTs anode was evaluated using a numerical simulation approach. The simulation findings results showed excellent consistency between numerical and experimental results.