Nanocellulose-Assisted Growth of Manganese Dioxide on Thin Graphite Papers for High-Performance Supercapacitor Electrodes

Abstract

High volumetric energy density, based on the entire electrodes, is necessary for the miniaturization of supercapacitors. The growth of manganese dioxide (MnO2) on graphite papers via chemical reactions was very limited, resulting in the inferior volumetric-specific capacitance. Cellulose nanofibers, coated on graphite papers, impressively enhanced the thickness of grown MnO2 layers and, thus, volumetric-specific capacitance. The symmetric supercapacitors displayed an extremely high volumetric energy density of 10.6 mWh/cm3 at a power density of 0.11 W/cm3. The performance was superior to that of MnO2-based symmetric and even asymmetric devices in the past studies. This research opens a new opportunity to fabricate high-performance supercapacitor electrodes by utilizing cellulose nanofibers detached from natural cellulose.

Silica‐assisted urea‐formaldehyde‐based carbon microspheres with enhanced supercapacitor performances as electrode

“…In addition, the inset of Figure (c) shows an enlarged Nyquist curve in the high‐frequency region and the arc curve is related to the equivalent series resistance, a semicircle in the high frequency; the radius of the semicircular area indicates the conductivity of the electrode material and the charge transfer resistance in the electrode material, respectively. The smaller the radius of the semicircles, the lower the impedance is which implies that the conductivity of the SUFCM‐1.0 electrode is best …”

Graphitic Carbon with MnO/Mn7C3 Prepared by Laser‐Scribing of MOF for Versatile Supercapacitor Electrodes

“…Manganese oxides are earth-abundant, low-cost, and multivalent materials that are promising for electrochemical supercapacitors. [27][28][29][30] Among various manganese oxides (e.g., MnO, MnO 2 , Mn 2 O 3 , MnO 3 , Mn 3 O 4, and Mn 2 O 7 ), MnO is known to exhibit an even higher theoretical capacitance of ≈1350 F g −1 with a wide voltage range of 1 V than the mostly studied MnO 2 (0.8 V). [22] The high capacitance of MnO is mainly attributed to its fast and reversible surface redox reaction (Mn(II) ↔ Mn(III) + e − ).…”

A Review on Nanocellulose and Its Application in Supercapacitors

“…For instance, cellulose nanofibers can promote the growth of MnO 2 on graphite paper, increasing the electrodes volume and resulting in high energy and power densities of 10.6 mWh cm −3 and 0.11 mW cm −3 , respectively (Table 3). [120] Even though there is an improvement in the rising energy density and power density, with the incorporation of nanocellulose and metal oxides as electrodes, the capacitance is still low and not satisfactory. Compared to the supercapacitor with cellulose nanofibers/Co 3 O 4 electrode (specific capacitance of 80 F g −1 ), there is a rise up to 600 F g −1 in specific capacitance when another conductive agent is added, be it carbon materials or conducting polymers.…”