Porous manganese dioxide nanosheets on modified graphite felt for cathodes in high-capacity flexible Zinc-MnO2 batteries. (September 2021)

• Record Type: Journal Article
• Authors: Yan, Chenhuan; Tong, Xin; Qu, Yihong; Zhou, Yang; Pang, Ning; Xu, Shaohui; Xiong, Dayuan; Wang, Lianwei; Chu, Paul K.
• Is Part Of: Vacuum. Volume 191(2021)
• Publication Date: 2021-09
• Subjects: Graphite felt -- Zn–MnO2 battery -- Surface modification -- Flexible devices -- Oxygen-containing functional groups; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2021.110353
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Modified graphite felt (MGF) is a flexible substrate with many advantages and a simple one-step method involving HNO3 is designed to activate graphite felt by increasing the amount of oxygen-containing functional groups and mesopores. Owing to the etching effect, excellent hydrophilicity beneficial to loading of α-MnO2 is achieved to facilitate the formation of MnO2 /MGF. The MnO2 /MGF structure serves as the cathode in a flexible Zn//MnO2 battery which also consists of a cross-linked polyacrylamide hydrogel as the electrolyte and separator and a Zn flake as the anode. The flexible Zn–MnO2 battery has excellent energy storage behaviors and cycling durability such as a high areal capacity of 1.26 mA h cm −2 at 4 mA cm −2 as well as capacity retention of 99.8% over 1000 cycles. Furthermore, the battery provides a remarkable energy density of 1.82 mW h cm −2 at a power density of 3.7 mW cm −2 . The modification strategy and materials have large potential in wearable and flexible devices. Highlights: A simple way was developed to increase the amount of oxygen-containing functional groups and mesopores of GF. MnO2 /MGF was used as the cathode and a cross-linked polyacrylamide hydrogel was acted as the electrolyte and separator. The flexible Zn//MnO2 battery has excellent energy storage behaviors and cycling durability.