Biodegradable Pea Protein Fibril Hydrogel-Based Quasi-Solid-State Zn-Ion Battery

Zinc-ion batteries show great potential as the next-generation power source due to their nontoxic, low-cost, and safe properties. However, issues with zinc anodes, such as dendrite growth and parasitic hydrogen evolution reactions (HERs), must be addressed to commercialize them. Solutions, such as quasi-solid-state electrolytes made from synthetic polymer hydrogels, have been proposed to improve battery flexibility and energy density. However, most polymers used are nonbiodegradable, posing a challenge to sustainability. In this study, hydrogels made from biodegradable poly(vinyl alcohol) and protein nanofibrils from pea protein, a renewable plant-based source, are used as an electrolyte in aqueous zinc-ion batteries. Results show that the flexible and biodegradable hydrogel can enhance the zinc anode stability and effectively restrict HER. This phenomenon is because of the hydrogen-bond network between nanofibril functional groups and water molecules. In addition, the interaction between functional groups on nanofibrils and Zn2+ constructs ion channels for the even migration of Zn2+, avoiding dendrite growth. The Zn||Zn symmetric cell using the hydrogel electrolyte exhibits a long lifespan of over 3000 h and improved capacity retention in the Zn||AC-I2 hybrid ion batteries by suppressing cathode material dissolution. This study suggests the potential of biodegradable hydrogels as a sustainable and effective solution for biodegradable soft powering sources

Highly Crumpled Hybrids of Nitrogen/Sulfur Dual-Doped Graphene and Co₉S₈ Nanoplates as Efficient Bifunctional Oxygen Electrocatalysts

A bifunctional electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly attractive for the manufacture of clean energy conversion devices. In this work, highly crumpled hybrid of nitrogen and sulfur dual-doped graphene and quasi-hexagonal Co₉S₈ nanoplates (Co₉S₈/NSG_g‑C3N4) is fabricated via a facile ionic assembly approach. The unique structure of Co₉S₈/NSG_g‑C3N4 renders it high specific surface area (288.3 m² g^–1) and large pore volume (1.32 cm³ g^–1). As the electrocatalyst for ORR, Co₉S₈/NSG_g‑C3N4 demonstrates excellent performance with the onset potential of −0.02 V vs Ag/AgCl and the limited current density of 6.05 mA cm^–2 at −0.9 V vs Ag/AgCl. Co₉S₈/NSG_g‑C3N4 also presents outstanding catalytic activity toward OER by delivering a limited current density of 48 mA cm^–2 at 1 V vs Ag/AgCl. The bifunctional catalytic behaviors of Co₉S₈/NSG_g‑C3N4 enable the assembly of a rechargeable Zn–air battery with it as the cathode catalyst, which exhibits stable discharge/charge voltage plateaus upon long time cycling over 50 h

Additional file 6: Table S3. of Comparative genomics reveals Cyclospora cayetanensis possesses coccidia-like metabolism and invasion components but unique surface antigens

Comparison of essential cellular metabolic pathways among some common apicomplexan parasites. (XLSX 70 kb