Unifying miscellaneous performance criteria for a prototype supercapacitor via Co(OH)₂ active material and current collector interactions

Abstract

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.

NiCoSe2/Ni3Se2 lamella arrays grown on N-doped graphene nanotubes with ultrahigh-rate capability and long-term cycling for asymmetric supercapacitor

“…With the significant increase in the consumption of portable electronic devices, electric vehicles and mobile phones, supercapacitors (SCs) have recently drawn much attention due to their ultrahigh power density, long-span cycle life, lightweight and environment friendliness [1][2][3][4][5]. The currently available SCs, although able to possess versatile features, only have an energy density that is one to two orders of magnitude lower than that of a typical rechargeable ion battery [6,7].…”

Ni(OH)2 nanoflakes supported on 3D hierarchically nanoporous gold/Ni foam as superior electrodes for supercapacitors

“…It can be observed that the specific capacitance of Ni(OH) 2 @NPG/Ni foam electrode showed a rapid loss of about 31.2% of its initial value in the first 1,000 cycles and then remained relatively constant in the subsequent 4000 cycles, in comparison with a serious 64% capacitance loss of the Ni(OH) 2 @Ni foam electrode after 1,000 cycles under the same conditions. As reported in a previous study, the choice of substrate has a significant effect on the cyclic stability of the electrode material, and Ni foam substrate is regarded as an inferior substrate to exhibit a poor cyclic stability for the TMOH-based electrode material since the formation of nickel oxide on the Ni foam surface leads to increased resistance between the electrode material and the current collector [41]. With NPG decoration on Ni foam, the R s for Ni(OH) 2 @NPG/ SCIENCE CHINA Materials.…”

“…Moreover, the specific capacitance of the Ni(OH) 2 @NPG/Ni foam electrode remains 1,645 F g -1 at a scan rate of 50 mV s -1 . The current collector plays a very important role in the electrochemical performance of the electrode material [41][42][43]. Such ultrahigh specific capacitance and excellent rate capability of the Ni(OH) 2 @NPG/Ni foam electrode could be mainly attributed to the significantly enhanced charge transport benefiting from the seamlessly integrated binder-and additive-free electrode with 3D hierarchical micro/nanoporosity, which makes full use of the conformally wrapped Ni(OH) 2 nanoflakes on the high surface area NPG/Ni foam composite current collector.…”

Integrated Co3O4/carbon fiber paper for high-performance anode of dual-ion battery

“…Consider the semiconductor nature of Co 3 O 4 , the increase of thickness may induce decrease of rate capacity. So proper deposition time has been chosen [32] . Then, the Co 3 O 4 /CFP composite is obtained by calcining Co(OH) 2 /CFP through a high temperature treatment, and the CFP remains stable at this temperature (Fig.…”