Porous shiitake mushroom carbon composite with NiCo2O4 nanorod electrochemical characteristics for efficient supercapacitor applications

Mushroom carbon based composite electrode with NiCo2O4 (m-C/NiCo2O4) nanorod arrays (NRAs), which improves the pseudocapacitive properties by effectively amplifying the electrochemical performance of supercapacitor. Carbon or graphene-based nanorod thin films have been used in supercapacitors with the low gravimetric (85-250 F g(-1), and areal (5-60 mF cm(-2)) specific capacitance values, which is undesirable for practical applications. In the present study, shiitake mushroom was used as the carbon source. The shiitake mushroom provides higher surface area and enhanced energy storage performance when compared with other carbon materials. m-C/NiCo2O4 composite made of NiCo2O4 nanorods combined with carbon nanoparticles made from shiitake mushroom using hydrothermal method, provides a higher specific capacitance when compared with carbon and other metal oxide/carbon composite electrodes. The formation of m-C/NiCo2O4 nanorod composite attributes to the higher surface area for the ion adsorption/desorption from the electrolyte, which resulted in a high specific capacitance. Porous properties of natural carbon and non-porous NiCo2O4 metal oxides effectively amplified the capacitance behavior and enhance stability. The physico-chemical and electrochemical characteristics of the samples are examined using various techniques. Therefore, the specific capacitance and excellent cycling stability have been improved using m-C combined with NiCo2O4. m-C/NiCo2O4 symmetric coin cell showed higher stability and high specific capacitance (556 F g(-1) at current density of 10 A g(-1)).