Mechanochemical production of graphene/amorphous carbon/Mn3O4 nanocomposites for asymmetric supercapacitor

• Published in: Applied surface science 2024-04, Vol.653, p.159388, Article 159388
• Main Authors: Li, Lin, Jiang, Yulin, Guo, Chao, Han, Kun, Cui, Xun, He, Chengen, Chen, Yihuang, Yang, Yingkui
• Format: Article
• Language: English
• Subjects: 3D porous structure; Asymmetric supercapacitors; Ball-milling; Excellent interfacial interaction; Graphene/amorphous carbon/Mn3O4
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.159388

[Display omitted] •GACMO is fabricated by a scalable ball-milling and subsequent annealing process.•AC wraps around Mn3O4 nanocrystals and attaches firmly to graphene sheet.•An ideal interfacial interaction and great 3D structure of the GACMO are presented.•An enhanced conductivity, reduced expansion, and alleviated agglomeration are shown.•GACMO shows excellent specific capacity, energy density, and cycle stability. The practical application of graphene/manganese oxide nanocomposites in energy storage presents a significant challenge due to their environmentally unfriendly and complex synthesis, as well as weak interface interactions. Herein, a sustainable and scalable ball milling-thermal annealing method is proposed to produce a graphene/amorphous carbon/Mn3O4 (GACMO) nanocomposite. A triblock copolymer is employed as an intercalator to facilitate the formation of few-layer graphene during ball-milling, a precursor for amorphous carbon to encapsulate Mn3O4 upon thermal-annealing, and thus an intermediate layer to enhance the interface interaction between graphene and Mn3O4. Benefiting from its 3D porous structure and exceptional interface design, GACMO exhibits a large specific surface area, excellent electrical conductivity, enhanced structural stability. Consequently, the GACMO electrode presents a high capacitance of 219 F g−1 at 0.5 A g−1 with a 91.4 % retention at 10 A g−1 after 5000 cycles. Furthermore, the GACMO-based asymmetric supercapacitor shows a high capacitance of 138 F g−1 at 0.5 A g−1, superior energy/power density (62.1 W h kg−1 at 0.45 kW kg−1, 0.6 mW h cm−3 at 9.3 mW cm−3), and promising cycling stability (88.3 % retention after 10,000 cycles). This study brings new insights into the fabrication of graphene/metal oxide-based energy materials.