A quasi-solid asymmetric supercapacitor based on MnO2-coated and N-doped pinecone porous carbon

Abstract

Porous carbon is considered as one of the most promising electrode materials for supercapacitors. In this work, we report a simple two-step preparation of porous carbon materials based on MnO 2 -coated and N-doped pinecone, which was synthesized by carbonization and hydrothermal process. After electrochemical analysis, the prepared 3-N-PC@MnO 2 electrode exhibited optimal electrochemical performance. At a current density of 1 A/g, the specific capacitance of 3-N-PC@MnO 2 was as high as 167.8 F/g in a voltage window of 0-1 V. After being assembled into an asymmetric supercapacitor with the PVA/Na 2 SO 4 quasi-solid electrolyte under the current density of 1 A/g, the energy density could reach 20.42 Wh/kg, the power density could achieve 799.9 W/kg, and its capacitance remained 84.5% after 3000 cycles, showing remarkable electrochemical performance.

Growth of Flower-like MnO2 on Porous ZIF-67 for Achieving Enhanced Supercapacitive Properties

“…42 The plentiful oxygencontaining functional groups could improve the hydrophilicity and wettability of the electrode materials and thus contribute to charge transfer in the electrolyte. 43,44 In terms of Mn 2p spectrum shown in Figure 5d, two intense peaks correlated with Mn 2p 1/2 and Mn 2p 3/2 are observed at binding energies of 654.3 and 642.6 eV, respectively, indicating the existence of abundant Mn 4+ and Mn 3+ . The binding energy and spin energy separation (11.7 eV) are in agreement with the previously reported values of δ-MnO 2 .…”

“…The high-resolution O 1s spectrum could be deconvoluted into two component peaks, corresponding to Mn–O–H (531.2 eV) and Mn–O–Mn (530.0 eV) bonds (Figure c), respectively . The plentiful oxygen-containing functional groups could improve the hydrophilicity and wettability of the electrode materials and thus contribute to charge transfer in the electrolyte. , In terms of Mn 2p spectrum shown in Figure d, two intense peaks correlated with Mn 2p 1/2 and Mn 2p 3/2 are observed at binding energies of 654.3 and 642.6 eV, respectively, indicating the existence of abundant Mn 4+ and Mn 3+ . The binding energy and spin energy separation (11.7 eV) are in agreement with the previously reported values of δ-MnO 2 . , With a nanoflower-like surface morphology, the δ-MnO 2 in ST@ZIF-67/MnO 2 can provide a large number of active sites for highly reversible chemical reactions during the charge–discharge cycling process.…”

Manganese dioxide (MnO2) and biomass-derived carbon-based electroactive composite materials for supercapacitor applications

“…It also displayed an energy density and power density of 20.42 W h kg −1 and 799.9 W kg −1 respectively. 119 Sui et al prepared an asymmetric SC using polypyrrole, MnO 2 , and N-doped carbon nanowires (PCNW). The PCNW porous structure made of polypyrrole nanowires serves as a supportive substrate for the deposition of MnO 2 via a redox reaction between carbon and KMnO 4 .…”

“…It also displayed an energy density and power density of 20.42 W h kg −1 and 799.9 W kg −1 respectively. 119…”