CNT assisted anomalous Li+ transport in CS/CMC solid biopolymer nanocomposite: an electrolyte in hybrid solid-state supercapacitors

• Published in: Ionics 2022-03, Vol.28 (3), p.1403-1418
• Main Authors: Majumdar, Simantini, Sen, Pintu, Ray, Ruma
• Format: Article
• Language: English
• Subjects: Activated carbon; Biodegradability; Biopolymers; Carbon nanotubes; Carboxymethyl cellulose; Cellulosic resins; Chemistry; Chemistry and Materials Science; Chitosan; Cobalt ferrites; Composition effects; Condensed Matter Physics; Current carriers; Dopants; Electrochemistry; Electrode materials; Electrolytes; Energy Storage; Functional groups; Ion dynamics; Leakage current; Lithium perchlorates; Manganese; Molten salt electrolytes; Nanocomposites; Optical and Electronic Materials; Original Paper; Polymers; Renewable and Green Energy; Solid electrolytes; Solid state; Spectrum analysis; Supercapacitors
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-021-04389-z

A conducting biodegradable solid polymer nanocomposite electrolyte (conductivity of the order ~ 10 −3 S/cm) comprising of the blend of chitosan (CS) and carboxymethyl cellulose (CMC), plasticized with glycerol, lithium perchlorate (LiClO 4 ) as dopant salt, and carbon nanotube (CNT) as nanofiller, has been prepared. The ion dynamics and charge carrier relaxation properties in CNT-incorporated solid biopolymer nanocomposite electrolytes are studied. The scaling of the conductivity and permittivity spectra is performed to study the effect of dopant composition on the relaxation mechanism. The anomalous intra-diffusive behavior of the charge carriers inside the blended polymer matrix has been investigated based on the fractional diffusion model. FTIR spectroscopy results suggest that the secondary amide functional groups of chitosan dominate the conduction mechanism. Transference number analysis confirms the predominant ionic conduction in the CNT-incorporated CS/CMC blended solid nanocomposite electrolytes. A very low leakage current of ~ 6 µA has been obtained with the CNT-incorporated solid nanocomposite electrolyte which makes it attractive for energy storage applications. A symmetric hybrid solid-state supercapacitor has been fabricated with active carbon and nanocrystallites of manganese cobalt ferrite (MnCoFeO 4 ) as electrode materials and CNT-incorporated CS/CMC blended biopolymers as solid-state nanocomposite electrolyte, offering a fairly good effective specific capacitance of ~ 94 Fg −1 .