MnO2 porous carbon composite from cellulose enabling high gravimetric/volumetric performance for supercapacitor

Preparing electrode material integrated with high gravimetric/volumetric capacitance and fast electron/ion transfer is crucial for the practical application. Owing to the structural contradiction, it is a big challenge to construct electrode material with high packing density, sufficient ion transport channels, and fast electronic transfer pathways. Herein, MnO 2 porous carbon composite with abundant porous structure and 3D carbon skeleton was facilely fabricated from Linum usitatissimum . L stems via NaOH activation and MnO 2 introduction. The in-situ introduced MnO 2 not only increases the packing density and the electrical conductivity of the porous carbon but also provides more active sites for oxidation reactions . These unique characteristics endow the resultant MnO 2 porous carbon composite with remarkable gravimetric capacitance of 549 F g −1 , volumetric capacitance of 378 F cm −3 , and capacitance retention of 54.9 %. Giving the simple process and low cost, this work might offer a new approach for structural design and the practical application of high-performance electrode materials.