Reinforcing active sites and multi-empty orbitals on N, S, B co-doped lignin-based catalysts for rechargeable zinc-air batteries

The advancement of rechargeable zinc-air batteries (ZABs) faces significant challenges, particularly due to substantial polarization and the slow kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Multi-element doping represents an effective strategy to address the deficiencies in catalytic activity and stability observed in single-atom catalysts. In this study, we prepare an activated lignin carbon catalyst doped with three elements (N, S, and B) via salt assisted (KOH), referred to as AL-NSB, with the aim is to achieve bifunctional catalysis through the synergistic interaction between the three elements to influence the distribution of the electron cloud and the extent of carbonaceous defects within the catalyst. The catalyst exhibits an ORR half-wave potential ( E 1 / 2 ) of 0.798 V relative to the reversible hydrogen electrode. The superior activity of AL-NSB results in a peak power density of 293.76 mW cm − 2 for the ZAB, along with an excellent cycle lifetime exceeding 1000 h, surpassing the performance of commercial Pt/C-RuO 2 catalysts. The findings of this study underscore the critical roles of N, S, and B in enhancing the activity and stability of both the oxygen reduction and evolution reactions.