Enhancing high ionic conductivity of polyacryamide/hemp cellulose nanofibers for utilizing as quasi solid electrolyte composites in flexible rechargeable zinc-ion battery with high-safety

Rechargeable zinc-ion batteries (ZIBs) have attracted broad interest in the large-scale energy storage industry as well as wearable and portable electronics. This work presents safe quasi-solid-state zinc-ion batteries (QZIBs), highlighting the use of polyacrylamides (PAM)/hemp-derived cellulose nanofibers (CNFs) as quasi-solid electrolyte (QSE) composites with cobalt manganese carbon nanofibers (CMO-CNFs) cathode composites. Results demonstrate that CNFs with different concentrations (0.25, 0.50, 0.75, and 1.0 wt%), in addition to PAM, show superior electrolyte uptake and high ion conductivity. For plating/stripping testing with a symmetrical zinc cell, PAM/CNFs 1.0 wt% (PNC1) are seen to display the lowest overpotential with the best zinc dendrite suppression feature. For the QZIB performance test, innovatively constructed Zn//PNC1//CMO-CNFs achieve remarkable electrochemical performance. A high discharge specific capacity of 207.84 mA g⁻¹ at a current density of 0.05 A g⁻¹, as well as during cyclic stability, outstanding 59% capacity retention after 500 cycles is obtained. Furthermore, QZIB exhibits promising prospects, demonstrating robust stability after various mechanical stresses. Moreover, PNC1 maintains seamless operation even at sub-zero temperatures, enhancing its applicability across diverse environmental conditions.