Spherical mesocrystals from self-assembly of folic acid and nickel(II) ion for high-performance supercapacitors

The formation of spherical mesocrystalline microparticles (FA-Ni) was achieved through the self-assembly between folic acid and nickel ions. Such favorable structure and the existence of abundant active sites within FA-Ni were responsible for the high specific capacitance (912 F g(-1) at 0.5 A g(-1)) and energy density (27.81 Wh kg(-1)) of the material when used as a supercapacitor. Meanwhile, the as synthesized FA-Ni showed excellent stability (97.6% capacitance retention over 8000 cycles at 10 A g(-1)). This facile method would be expected to benefit for the preparation of mesocrystals based on biological ligands and their use as the promising electrode materials for high performance supercapacitors. (C) 2018 Elsevier Inc. All rights reserved.