Recently, Mr. Du Dongfeng, a postgraduate student from college of science, China University of Petroleum, published a cover paper entitled ”Remarkable supercapacitor performance of petal-like LDHs vertically grown on graphene/polypyrrole nanoflakes”in the Royal Society of Chemistry journal, Journal of Materials Chemistry A (2017, 5, 9422-9422).'
Nowadays, with the growing energy demand, there is an urgent need to develop clean, efficient, low cost and sustainable new energy storage devices. Supercapacitor with the characteristics of high power, high capacity, short charging time, long cycle life and wide working temperatures, has received widespread attentions. The electrode material of supercapacitor is a key to its energy storage performance. Based on energy storage mechanisms, electrode materials used in supercapacitor can be divided into electric double layer capacitor materials and faraday capacitor materials. The electric double layer capacitance materials have good conductivity and cycle stability, but very limited charge storage capacitor. By contrast, the faraday capacitance materials have very high charge storage capacity, but low conductivity and cyclic stability. Working alone, neither of these two kinds of materials can perform well. Accordingly, combining the electric double layer capacitance and faraday capacitance materials is the key to further improve the capacitive performance.
Mr. Du synthesized a new type of three-dimensional layered double hydroxide metal/graphene/polypyrrole composite using cheap transition metal hydroxide and graphene/polypyrrole. The structure and morphology of this three-dimensional composite were optimized and well controlled. Moreover, the paper revealed the synergetic enhancement effect among layered double hydroxide, graphene and polypyrrole. As a substrate, the graphene/polypyrrole not only provides fast electron transport channel, but also contributes to form stable metal hydroxide/polypyrrole interface, which is vital for the cycle stability of this material. At the same time, layered double hydroxides with thickness of 3-5 nm are uniformly vertical distributed on the surface of the graphene/polypyrrole, which can not only effectively restrain the aggregation of conductive substrates, but also provide a large number of electrochemical reactive sites. This special structure enables the material ultrahigh capacitance (2395 F/g, close to its theoretical capacity), excellent power characteristic and excellent stability (almost no decay after 10,000 cycles). In addition, the material can also be used directly as a model material to electrochemical sensors, storage batteries, photoelectric catalysis and other related fields.
Paper details:
http://pubs.rsc.org/en/content/articlelanding/2017/ta/c7ta00624a#!divAbstract
Cover details:
http://pubs.rsc.org/en/content/articlepdf/2017/ta/c7ta90105d?page=search
Editor: Bu Lingduo
Source: UPC News Center
updatetime: 2017-06-02
