A green gel polymer electrolyte combining sodium alginate, lignin and Na2SO4 was compositionally optimized. Conductivity reached 2.91×10^-4 S/cm versus 2.09×10^-5 S/cm in the baseline, about a 13.9-fold increase. Dielectric and electric-modulus analysis indicated shorter relaxation and improved carrier dynamics, ionic transference reached 0.98, and the stability window reached 2.85 V. Excess salt caused ion association and reduced transport.
Key findings
- Conductivity rose from 2.09×10^-5 to 2.91×10^-4 S/cm; ionic transference reached 0.98; the window reached 2.85 V; optimal salt balanced carrier density and mobility, while excess salt promoted ion association.
Why this matters globally
Renewable alginate and lignin could reduce fossil-derived content in storage devices, while the polymer-salt interaction strategy may transfer to other biobased electrolytes.
Thai researcher contribution
Everton Granemann Souza is affiliated with Thailand's National Electronics and Computer Technology Center, linking a Thai research agency to biobased energy materials and ion-transport analysis.
Limitations to consider
Conductivity is a material-level metric sensitive to temperature and humidity. Tensile strength, leakage, thermal durability, long-term cycling and full-cell performance are absent. A 2.85-V window may constrain electrode chemistry, and ‘green’ requires manufacturing and end-of-life evidence.