Electrochemically grown nanoporous MnO2 nanowalls on a porous carbon substrate with enhanced capacitance through faster ionic and electrical mobility

Abstract

We report the deposition of uniform porous MnO2 nanowalls on a conducting carbon fiber substrate using a simple electrochemical method, which produces ordered nano-channels demarcated by the MnO2 walls for easy ion transport and a continuous electron path created by the carbon backbone. The system achieves a specific capacitance of 1149 F g(-1) and retains 565 F g(-1) even at dragging conditions as high as 100 A g(-1).

High‐Performance Fiber‐Shaped All‐Solid‐State Asymmetric Supercapacitors Based on Ultrathin MnO2 Nanosheet/Carbon Fiber Cathodes for Wearable Electronics

“…[35][36][37] Moreover, such a quasi-rectangular shape is well retained even at the scan rate up to 300 mV s −1 , indicating good high-rate performance. Except for CV measurement, the charge-discharge curves exhibit the nearly symmetric feature without obvious IR drop (Figure 3 c), also suggesting excellent electrochemical capacitive characteristics and reversible Faradaic reaction between Na + and the ultrathin MnO 2 .…”

Self-grown MnO 2 nanosheets on carbon fiber paper as high-performance supercapacitors electrodes

“…3(d) obviously reveals a lattice spacing of 0.35 nm, which corresponds to the (002) plane of MnO 2 . This peculiar morphological structure helps the electrode to establish highly active interfacial areas and pathways for ion transport within the electrode [35].…”

Hierarchical polypyrrole based composites for high performance asymmetric supercapacitors

“…[32] For MnO 2 , Q is is total charge of the electrodeposition process, M MnO2 is the molecular mass of MnO 2 , F is the Faraday constant, Z is the number of electrons of the Mn ion transferred from Mn 2+ to MnO 2 (Mn 2+ + 2H 2 O = MnO 2 + 4H + + 2e -). [33] The loading mass of both PPy and MnO 2 can be tunable through changing the electrodeposition time. The mass ratio of active material [PPy (0.35 mg) : MnO 2 (1.00 mg)] for the optimized Ni@PPy@MnO 2 anode is about 1 : 3.…”