Tuning Mn2+ additive in the aqueous electrolyte for enhanced cycling stability of birnessite electrodes. (1st March 2019)

• Record Type: Journal Article
• Authors: Liu, Cuiyin; Chen, Yanfeng; Dong, Zhiyong; Wu, Xiaojuan; Situ, Yue; Huang, Hong
• Is Part Of: Electrochimica acta. Volume 298(2019)
• Page Start: 678
• Page End: 684
• Publication Date: 2019-03-01
• Subjects: Birnessite -- Hierarchical nanosheets -- Enhanced cycling stability -- Mn2+ -- Pseudocapacitors; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.12.123
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Long-term cycling stability is a main issue for the application of manganese-based electrodes in pseudocapacitors. Herein, we demonstrate a facile approach to enhance the cycling stability of birnessite electrodes by pre-adding slight Mn 2+ into the aqueous electrolyte. The cycling performance of the electrode and the morphology of birnessite change with Mn 2+ concentration, which are ascribed to the electrochemical oxidation of Mn 2+ or the reduction of birnessite during the charge/discharge cycling process. By controlling a low concentration of Mn 2+, the birnessite electrode exhibits enhanced capacitance and cycling stability, while a hierarchical nanosheets assembled nanowall array architecture is achieved after the prolonged cycling. The resulting electrode delivers a superior rate capability (60% retention at 20 A g −1 ) and a high cycling stability (93% retention after 10000 cycles). This work opens up a new strategy for the development of manganese-based electrodes with high rate performance and long-term cycling stability. Graphical abstract: Highlights: A facile approach to enhance cycling stability of birnessite electrodes. Controlled cycling performance and variational morphology with Mn 2+ concentration. In situ formation of hierarchical nanosheets assembled nanowall array architecture. A high cycling stability with capacitance retention of 93% after 10000 cycles.