Solid-State Rechargeable Zinc-Air Battery with Long Shelf Life Based on Nanoengineered Polymer Electrolyte

Zinc-air batteries (ZABs) are vulnerable to the ambient environment (e.g., humidity and CO₂ ), and have serious selfdischarge issues, resulting in a short shelf life. To overcome these challenges, a near-neutral quaternary ammonium (QA) functionalized polyvinyl alcohol electrolyte membrane (different from conventional alkali-type membranes) has been developed. QA functionalization leads to the formation of interconnected nanochannels by creating hydrophilic/-phobic separations at the nanoscale. These nanochannels selectively transport OH^- ions with a reduced migration barrier, while inhibiting [Zn(NH₃ )₆ ]²⁺ crossover. Owing to the superior water retention ability and enhanced chemical stability of the membrane, the solid-state zinc-air battery (SZAB) displays outstanding flexibility, a promising cycle lifetime, and a large volumetric energy density. More importantly, the self-discharge rate of SZAB is depressed to less than 7 % per month, and the fully dehydrated SZAB could recover its rechargeability upon replenishment of the solution of NH₄ Cl.

A novel electro-catalytic degradation method of phenol wastewater with Ti/IrO2-Ta2O5 anodes in high-gravity fields

In the electro-catalytic degradation process of phenol wastewater, bubbles and mass transfer limitation will result in the decrease in wastewater degradation efficiency, a long electrolysis time and a high energy consumption. Self-made Ti/IrO₂-Ta₂O₅ anodes and a high-gravity electro-catalytic reactor were used to improve them. The Ti/IrO₂-Ta₂O₅ anode was prepared with a thermal decomposition method and characterized by scanning electron microscopy (SEM). Under optimum conditions, the removal efficiencies of phenol, total organic carbon (TOC) and chemical oxygen demand (COD) respectively reached 94.77%, 50.96% and 41.2% after 2 h electrolysis in the high-gravity field, which were respectively 10.93%, 16.72% and 24.84% higher than those in the normal gravity field. For about the same removal efficiencies, the electrolysis time and energy consumed in the high-gravity field were 33.3% and 15.4% lower than those consumed in the normal gravity field, respectively. The degradation pathway of phenol detected by high performance liquid chromatography (HPLC) was unchanged in the high-gravity field, but the degradation rate of phenol increased. The Ti/IrO₂-Ta₂O₅ anode provided good stability because the removal efficiencies of phenol and TOC decreased slightly and the surface morphology of the coating was almost unchanged when it had been used in electrolysis for 11 months, about 1,200 h, in the high-gravity field. Results indicated that the phenol wastewater degradation efficiency was improved, the time was shortened, and the energy consumption was reduced in the high-gravity field.

Sonoelectrochemical effects in electro-organic systems

This paper describes recent studies in organic sonoelectrochemistry at Coventry University, including the oxidation of thiophene monoxides, degradation of dye pollutants, formation of conducting polymers and electrosynthetic modification of proteins.