Cover Image, Volume 50, Issue 5

The search for an inexpensive, flexible, and light-weight electrode for batteries and supercapacitors has led to wide-ranging investigations on polypyrrole because of its easy electrochemical processability, high charge storage ability, biocompatibility, and good thermal and environmental stability. The interaction between the anion and the polymer chain holds the key to the genesis of its structural, optical, and electrical properties. The inorganic anions show 3D-type growth leading to fractal morphology whereas organic anions form a compact stack with the polymer backbone exhibiting a laminar structure. The investigation by Rajiv K. Singh, Amit Kumar, Khushboo Agarwal, Mahesh Kumar, H. K. Singh, Pankaj Srivastava, and Ramadhar Singh on page 347 reveals that the anions used for polymerization have considerable impact on the growth mechanism.