Mercerization effect on structure and electrical properties of cellulose: Development of a novel fast Na-ionic conductor

•Novel Na-ionic conductor based on alkali-cellulose was recognized.•The insertion of Na-ion in cellulose improved its electrical behavior.•The alkali-cellulose and its precursor were characterized by solid state 13C-NMR.•Thermal study of alkali-cellulose was proved to be higher than a parent cellulose. Mercerized cellulose (alkali cellulose C6H10O5* NaOH) was obtained by treatment of cotton linters (cellulose) with aqueous sodium hydroxide. Cellulose and alkali-cellulose samples with relative density of 78% and 79% were obtained after sintering the material in air at optimal sintering temperatures of 423 K and 473 K, respectively. The electrical properties of the samples were studied by impedance spectroscopy in the frequency range from 13 MHz to 50 Hz at temperatures between 393 K and 493 K. The influence of cellulose mercerization on electrical properties of cotton linters was observed. The cellulose behaves like an electrical insulator. Contrariwise, the alkali-cellulose is a fast-ionic conductor with a conductivity value of σ473 K = 3.22 × 10−6 S cm−1 having activation energies of 0.49 eV and 0.68 eV at temperature range of 393 K–458 K and 459 K–500 K, respectively. The change of activation energy value has been discussed in relation to thermal stability.