Morphology-dependent electrochemical properties of sol-gel synthesized LiCoPO4 for aqueous hybrid capacitors

• Published in: Electrochimica acta 2018-11, Vol.289, p.516-526
• Main Authors: Priyadharsini, Natarajan, Shanmugapriya, Sathyanarayanan, Kasturi, Palanisamy Rupa, Surendran, Subramani, Selvan, Ramakrishnan Kalai
• Format: Article
• Language: English
• Subjects: Hybrid capacitor; Lithium cobalt phosphate; Morphological effect; Olivine; Sol-gel synthesis
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2018.08.086

Featured with superior structural stability and highest redox potential, the olivine LiCoPO4 parades itself as a conceit battery-type material. To deploy its foot in the field of hybrid supercapacitors a series of LiCoPO4 with three contrasting morphologies were achieved. The evolution of morphology from clustered microspheres to elongated rods and multifaceted submicronic particles has an appreciative effect on the particle size and electrochemical properties. Endowed with distinct qualities such as high crystallinity, and multifaceted morphology, LiCoPO4 prepared at alkaline pH provides a superior specific capacity of 381 C g−1 (1060 F g−1) at 1 mV s−1 and a maximum discharge specific capacity of 253 C g−1 (631 F g−1) at 0.6 mA cm−2. The fabricated hybrid supercapacitor using prepared LiCoPO4 at the pH-12 condition as a battery type positive electrode and Fe2O3 as the negative electrode provides a grander energy density of 18 Wh kg−1 at an enhanced power density of 443 W kg−1 with a sustained cyclic performance for about 5000 cycles.