Robust electrochemical performance of polypyrrole (PPy) and polyindole (PIn) based hybrid electrode materials for supercapacitor application: A review

One of the basic intentions of science and technology is the evolution of novel and more efficient devices to make human life more easy and comfortable. A supercapacitor is one such device that can be utilized as a complementary and to some extent a replacement of electrochemical battery to store electrical energy. The performance of a supercapacitor very much depends on the electrode material used and hence a variety of materials are employed to form electrodes of supercapacitors in order to improve its performance. In this review, we have discussed the preparation and properties of polypyrrole (PPy) and polyindole (PIn) based electrode material for supercapacitor applications. PPy shows a high degree of flexibility which makes it markedly suitable and applicable for making flexible supercapacitors. PIn exhibit slow hydrolytic degradation and hence long chargedischarge time. Thus, PIn can be utilized to form supercapacitors having the ability to store energy for a longer period of time. Nonetheless, their properties can be enhanced by using binary and ternary composites of PPy and PIn with different carbon-based and metal-based materials. This review briefly discusses some of these composites and devices formed by them.