Whole Landscape of the Origin and Evolution of Gassing in Supercapacitors at a High Voltage.

Although supercapacitors with acetonitrile-based electrolytes (AN-based SCs) have realized high-voltage (3.0 V) applications by manufacturers, gas generation at high voltages is a critical issue. Also, the exact origins and evolution mechanisms of gas generation during SC aging at 3.0 V still lack a whole landscape. In this work, floating tests under realistic working conditions are conducted by 22450-type cylindrical cells with an AN-based commercial electrolyte. Comprehensive insights into the origins and evolution mechanisms of gas species at 2.7 and 3.0 V are acquired, which involves multiple side reactions related to the electrode, current collector, and electrolyte. Both experimental evidence and density functional theory calculations demonstrate that the primary reasons for gas generation are residual water and oxygen-containing functional groups, especially hydroxyl and carboxyl. More importantly, additional types of gas (such as CO2, NH3, and alkenes) can only be detected at a higher voltage of 3.0 V rather than 2.7 V after failure, suggesting that these gas species can be regarded as the failure signatures at 3.0 V. This breakthrough analysis will provide fundamental guidance for failure evaluation and designing AN-based SCs with extended lifetime at 3.0 V.

Orally Administrated Whole Yeast Vaccine Against Porcine Epidemic Diarrhea Virus Induced High Levels of IgA Response in Mice and Piglets.

The mucosal immune response against the porcine epidemic diarrhea virus (PEDV) is very important in piglets. To develop a PEDV vaccine suitable for inducing high levels of intestinal IgA in piglets, recombinant yeast expressing the PEDV S1 gene was constructed and tested by oral immunization of mice and piglets. The S1-specific IgG and IgA were tested at 0, 14, and 28 days postimmunization (dpi) in mice. Compared to the control group, the mice treated with S1 expressing yeast, demonstrated significantly higher levels of IgG and IgA against PEDV from 14 dpi onward. The recombinant yeast inducing a fecal IgA response in piglets was also tested. PEDV-specific IgA could be detected at 7 dpi and increased to 28 dpi. We demonstrated that whole recombinant yeast can be used as a PEDV vaccine vector for inducing high levels of IgA against PEDV in piglets. This could be a good vaccine candidate for PEDV control in piglets.