Premium
New Insight into the Mechanism of Multivalent Ion Hybrid Supercapacitor: From the Effect of Potential Window Viewpoint
Author(s) -
Liu Yupeng,
Zhang Yaxiong,
Sun Zhenheng,
Cheng Situo,
Cui Peng,
Wu Yin,
Zhang Junli,
Fu Jiecai,
Xie Erqing
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202003403
Subject(s) - supercapacitor , electrochemistry , materials science , electrolyte , electrode , ion , capacitance , nanotechnology , energy storage , electrochemical window , intercalation (chemistry) , power density , chemical engineering , optoelectronics , inorganic chemistry , chemistry , ionic conductivity , power (physics) , physics , organic chemistry , quantum mechanics , engineering
Multivalent ion hybrid supercapacitors have been developed as the novel electrochemical energy storage systems due to their combined merits of high energy density and high power density. Nevertheless, there are still some challenges due to the limited understanding of the electrochemical behaviors of multivalent ions in the electrode materials, which greatly hinders the large scale applications of its based hybrid supercapacitors. Herein, the long‐term electrochemical behaviors of MnO 2 ‐based electrode in the divalent Mg 2+ ions electrolyte are systematically studied and linked with the morphological and electronic evolution of MnO 2 by cycling at different potential windows (spanning to 1.2 V). It reveals that the different potential windows result in the different electrochemical behaviors, which can be divided into two ranges (below and above −0.2 V). And, the electrode cycled at a potential window of 0–1.2 V delivers the highest capacitance of 967 F g −1 at a scan rate of 10 mV s −1 , in which the MnO 2 is transformed into a uniformly distributed and nonagglomerated nanoflake morphology promoting the intercalation and deintercalation of Mg 2+ ions. This study will enrich the understanding of the charge storage mechanism of multivalent ions and provide significant guidance on the performance improvement of the hybrid supercapacitors.