Such facile and low-cost synthesis of pseudocapacitive materials with porous nanopaths is favorable for the fabrication of high-performance energy storage devices.
The preparation of porous graphene with a high surface area by the introduction of pseudocapacitive materials such as metal oxides or conducting polymers to graphene sheets for hybrid materials is one of the efficient approaches for improving the performance of graphene-based supercapacitors [6,7].
More importantly, fast capacitance fading of pseudocapacitive materials upon mass loading increase can be suppressed by the novel structure, making it a good candidate for supercapacitor electrode with high areal capacitance.
The drawbacks of these pseudocapacitive materials are the lack of long-term stability and rather slow charge/discharge time because of the swelling and shrinking of polymers [10].
Firstly, the two kinds of excellent pseudocapacitive materials densely cover on the entire surface of carbon fiber without using additives thus to provide more active spaces and improved electron transfer pathways.
In fact, the pseudocapacitive behaviour of electrode materials is of particular importance in battery systems and electrocatalysis as well.
So, it is a basic fundamental guideline that the preparation of higher-performance pseudocapacitive materials depends on achieving and accelerating more Faradaic reactions in the aspect of electrodes.
Thus, the development of rigorous models for materials structure, materials defects, microstructure evolution, and the behaviour of materials became a second thrust of materials science.
Among various electrode materials, Co3O4 is one of the most extensively investigated pseudocapacitive materials because of its low cost, environmental friendliness and high theoretical capacitance (~3560 F g−1) [8].
The low active ratio of traditional (only surface-active) pseudocapacitive materials limits the fabrication of electrochemical energy storage/conversion devices with high volumetric energy densities.
