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Unifying miscellaneous performance criteria for a prototype supercapacitor via Co(OH) 2 active material and current collector interactions
Author(s) -
WANG H.X.,
ZHANG W.,
DREWETT N.E.,
ZHANG H.B.,
HUANG K.K.,
FENG S.H.,
LI X.L.,
KIM J.,
YOO S.,
DENG T.,
LIU S.J.,
WANG D.,
ZHENG W.T.
Publication year - 2017
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/jmi.12545
Subject(s) - supercapacitor , materials science , cobalt hydroxide , electrochemistry , valence (chemistry) , current collector , nanotechnology , fabrication , electrode , substrate (aquarium) , cobalt , chemical engineering , transition metal , hexagonal crystal system , redox , catalysis , crystallography , chemistry , metallurgy , electrolyte , medicine , biochemistry , alternative medicine , oceanography , organic chemistry , pathology , engineering , geology
Summary The use of transition metal oxides and hydroxides in supercapacitors can yield high specific capacity electrodes. However, the effect of interaction between active material and current collector has remained unexplored. Here the behaviour of electrodeposited hexagonal cobalt hydroxide nanosheets on a variety of substrates was investigated, and the resulting valence bonding, morphological evolutions and phase transformations examined. It is shown that the electrochemical activity of the face centred cubic (FCC) Ni substrate dramatically decreases cyclability, the FCC Cu substrate also demonstrates decreased performance, and hexagonal carbon nanofibre (CNF) and Ti substrates exhibit far more stability. The miscellaneous roles of valence bonding, redox reactions and crystal structure mismatch between active material and current collector are examined, and their consequences discussed. Using the resulting insights into performance criteria, it was possible to select a suitable substrate for the fabrication of an asymmetric supercapacitor. The high performance and stability of the device demonstrates the usefulness of this approach, and the utility of applying these insights to energy storage devices.