1,4-Naphthoquinone

All‐solid‐state rechargeable air batteries are designed and fabricated using 1,4‐naphthoquinone as a negative electrode, proton‐conductive polymer membrane as a solid electrolyte, and platinum‐based oxygen diffusion as a positive electrode as an emerging energy device. 1,4‐Naphthoquinone molecules exhibit reversible redox reactions peaked at 0.28 and 0.52 V versus reversible hydrogen electrode with the polymer electrolyte similar to that in an acid aqueous solution. The all‐solid‐state rechargeable air battery cell shows an open circuit voltage of 0.83 V, a nominal voltage of 0.3–0.4 V, a discharge capacity of 83.6 mAh g−1, and an initial Coulombic efficiency of 86.8%. The Coulombic efficiency after 15 charge–discharge cycles improves from 57.3% to 69.1% by replacing carbon black with graphite carbon as a support for the platinum catalyst in the positive electrode. Furthermore, replacing the commercial Nafion electrolyte membrane with the synthesized (in‐house) polyphenylene‐based ionomer (sulfonated polyphenylene‐quinquephenylene) electrolyte membrane improves the cycle durability of the resulting all‐solid‐state rechargeable air battery with high Coulombic efficiency retention (>98%) after 135 cycles owing to the lower oxygen permeability of the latter membrane. Overall, the present all‐solid‐state rechargeable air battery using 1,4‐naphthoquinone outperforms our previous all‐solid‐state rechargeable air battery using dihydroxybenzoquinene as a redox‐active molecule.

Advanced redox electrolytes are essential for boosting the electrochem. performance of hybrid capacitors, which merge the high-power d. of supercapacitors with the energy d. of metal-ion batteries.This work focuses on the development of redox electrolytes using naphthoquinone compoundsA series of naphthoquinone derivatives with diverse structures were investigated for their application in zinc-ion hybrid capacitors (ZICs).The results reveal that naphthoquinone mols. featuring adjacent bonding ligands exhibit enhanced stability of zinc anodes due to their bidentate behavior, which facilitates strong chelating interactions with metal atoms.The redox electrolyte, prepared by 2-Hydroxy-1,4-naphthoquinone (HNQ), improves the durability of Zn//Zn cells from 24 to 972 cycles at 1 mAh cm^-2 and 2 mA cm^-2.Moreover, the ZIC based on the HNQ-containing electrolyte demonstrates an increased capacity of 82.2 mAh g^-1, compared to 64.4 mAh g^-1 for the pristine ZnSO₄ electrolyte.The findings underscore the dual role of redox electrolytes in improving the electrochem. stability of zinc anodes while simultaneously enhancing the capacity of ZICs.