Novel approach for the utilization of ionic liquid-based cellulose derivative biosourced polymer electrolytes in safe sodium-ion batteries

Carboxymethyl cellulose (CMC) derived from kenaf bast fiber complexed with sodium acetate and integrated with ionic liquid 1-butyl-3-methylimidazolium chloride, [Bmim]Cl, was investigated as potential biosourced polymer electrolyte. The highest ionic conductivity of (4.54 +/- 1.2) x 10(-3) S cm(-1) was obtained after introducing 30 wt% [Bmim]Cl with respect to the weight of CMC. Infrared spectroscopic analysis revealed the interaction of the polymer host with the sodium salt and ionic liquid. Ion transport analysis showed that charge transport in the biopolymer electrolyte system occurred predominately with ion and sodium ion transference numbers of 0.129. Linear sweep voltammetry result showed that electrochemical stability reached similar to 2.9 V, showing that the biopolymer electrolyte is suitable for practical application in electrochemical devices. Sodium battery configurations of Na/CH3COONa-30 wt% [Bmim]Cl/I-2 + C + electrolyte were fabricated and demonstrated an initial discharge capacity of 1.5 mAh for 200 h with 1.6 V open circuit potential.

Automated summary

In this study, carboxymethyl cellulose (CMC) derived from kenaf bast fiber was complexed with ionic liquid [Bmim]Cl to investigate its potential as a biosourced polymer electrolyte. The highest ionic conductivity was achieved by introducing 30 wt% [Bmim]Cl, showing promising characteristics for practical application in electrochemical devices. Sodium battery configurations using this biopolymer electrolyte demonstrated good initial discharge capacity and stability.