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

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 17; no. 29
• Main Authors: Lam, Do Van, Nguyen, Uyen Nhat Trieu, Roh, Euijin, Choi, Wanuk, Kim, Jae‐Hyun, Kim, Hyunuk, Lee, Seung‐Mo
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.07.2021
• Subjects: Carbon; Carbothermic reactions; carbothermic reduction; catalytic graphitization; Encapsulation; Energy storage; Flexible components; graphitic carbon; Graphitization; laser‐scribing; Life span; Manganese oxides; Metal-organic frameworks; Nanoparticles; Nanotechnology; Supercapacitors; Synergistic effect
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202100670

Pseudocapacitive materials encapsulated in conductive carbon matrix are of paramount importance to develop energy storage devices with high performance and long lifespan. Here, via simple laser‐scribing, the Mn‐based metal–organic framework [EG‐MOF‐74(Mn)] is transformed into pseudocapacitive hybrid MnO/Mn7C3 encapsulated in highly conductive graphitic carbon. It is revealed that the rapid carbothermic reduction of MnO (C + MnO → C′ + Mn7C3 + CO) leads to the formation of the intermediate pseudocapacitive MnO/Mn7C3 and the concurrent catalytic graphitization of disordered carbon. This reaction produces a new type of pseudocapacitive material in the form of MnO/Mn7C3 fully embedded in highly conductive graphitic carbon. Thanks to the synergistic effect of the MnO/Mn7C3 nanoparticles and the graphitic carbon, the composite exhibits a high specific capacitance of 403 F g−1 with excellent stability. Asymmetric coin‐cell supercapacitors based on the composite demonstrate high energy (29.2 Wh kg−1) and power densities (8000 W kg−1) with a long lifespan. Prototypes of flexible paper‐based supercapacitors made of the composite also show great potential toward applications of flexible electronics. Pseudocapacitive materials encapsulated in conductive carbon matrix are of paramount importance to develop energy storage devices with high performance and long lifespan. Laser irradiation on Mn‐metal–organic framework (MOF) induces carbothermic reduction as well as catalytic graphitization simultaneously, thereby transforming the MOF into conductive nanoporous graphitic carbon encapsulating pseudocapacitive MnO/Mn7C3 nanoparticles for versatile supercapacitor electrodes.