Ultrafine Amorphous MnO x Nanoparticles for a High Mass Loading Electrode

• Published in: ACS applied nano materials 2024-12, Vol.7 (24), p.28593-28601
• Main Authors: Zhu, Shijin, Sun, Minghao, Jiang, Jingyi, Zhan, Xiafan, Du, Changyu, Ding, Cheng, Wei, Dehua, Huang, Xuechen
• Format: Article
• Language: English
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.4c05742

High electrochemically active manganese dioxide (MnO2) has been deemed to be a promising active material for a high mass loading electrode. Here, an amorphous MnO x nanostructure constituted by ultrafine MnO x nanoparticles was fabricated by a simple, controllable, and cost-effective strategy. The electrochemical properties of the as-prepared MnO x nanostructures were significantly improved due to their amorphous crystalline structure. For a high mass loading electrode, an optimized content of amorphous MnO x , carbon black, and carbon nanotubes was measured to be 79.1%, 13.5%, and 7.4%, respectively. A high mass loading electrode of 13.5 mg·cm–2 was fabricated with a capacitance of 371.3 F·g–1 calculated based on the weight of pure amorphous MnO x . Hence, a high mass loading asymmetric supercapacitor assembled by amorphous MnO x (12.6 mg·cm–2) and activated porous carbon (APC, 22.4 mg·cm–2) delivers an ultrahigh areal energy density of 780.3 μW h·cm–2. Furthermore, a good cycling stability with 98% of the initial capacitance retention was achieved after 8000 cycles, meeting the requirements of a commercial energy storage device.