A renewable bifunctional structural supercapacitor using the recycled geopolymer membrane and MnO2/CNTs electrode

• Published in: Journal of energy storage 2024-11, Vol.102, p.114203, Article 114203
• Main Authors: Liu, Jun-Hu, Yang, Jing-Lei, Yang, Fan, Feng, Jie, Yuan, Xia-Yue, Zhou, Juan, Ma, Xue-Jing, Zhang, Wei-Bin
• Format: Article
• Language: English
• Subjects: Geopolymer; Manganese dioxide; Renewable material; Structural supercapacitor
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2024.114203

A bifunctional supercapacitor based on the recycled montmorillonite geopolymer membrane and MnO2/CNTs composite electrodes was designed and assembled. The recycled geopolymer was prepared from recycled montmorillonite geopolymer powder and alkali activators and used as a solid electrolyte skeleton, with a maximum compressive strength of 30.6 MPa after 28 days of curing, which is comparable to the strength of the initially polymerized geopolymer. The MnO2/CNTs electrodes were prepared by electrodeposition method, and the electrode materials containing 2 wt% CTAB and 1 wt% CNTs had the best area specific capacity of 3310 mF cm−2 at a current density of 1 mA cm−2. The regenerated geopolymer electrolyte framework was injected with 0.5 M Na2SO4 and assembled with MnO2/CNTs electrode to form a structural load-bearing supercapacitor, which had a specific capacity of 2094.4 mF cm−2 at a load of 15 MPa, with a capacity retention rate of 65.43 % after 10,000 charge/discharge cycles. •A recycled geopolymer was prepared from recycled montmorillonite geopolymer and used as a solid electrolyte skeleton.•A MnO2/CNTs pseudocapacitive electrode is explored the effect of different conditions on the electrochemical properties.•A renewable bifunctional device of simultaneously carrying mechanics and storing energy is designed and constructed.•The device uses geopolymer electrolyte and pseudocapacitive electrode to store energy while resisting pressure.