Adding Value to Biomass via Energy Applications: High-Performance Biocarbon from Sewage Sludge for Supercapacitors and Fuel Cells
Year: 2025
Type: article
Abstract: A sewage sludge-derived biocarbon (SSB) was produced using biomass from a water treatment plant in Saltillo, Mexico. Its specific surface area was 412.0 m2 g−1, with an average pore diameter of 4.4 nm. Evaluation in an SSB||SSB symmetrical supercapacitor showed a high performance in several electrolytes (6 M KOH, 0.5 M Na2SO4, and 1 M NaClO4). The supercapacitor in KOH exhibited the highest specific capacitance (Csp) of 144.80 F g−1 at 1 mV s−1. Nevertheless, the widest operating voltage window of 2.5 V was attained in NaClO4. This enhanced behavior led to achieving energy density (ED) and power density (PD) values of 22.52 Wh kg−1 and 508.0 W kg−1, respectively, in the organic electrolyte. Moreover, rotating ring-disc electrode tests in 0.1 M KOH showed that SSB catalyzes the oxygen reduction reaction, with a low percentage of perhydroxyl ion produced ( % H O 2 − ) of 7.41% and a high electron transfer number (n) of 3.85 before an accelerated degradation test of 3000 cycles, sustaining a high stability after the cycling. This study provided evidence that high-performance active catalytic materials for symmetric supercapacitors and cathodes for anion exchange membrane fuel cells can be produced from Earth-abundant sewage sludge biomass.
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $1,950
Award: G3007173845
OpenAlex ID: W4408319950