2025-09-24 テキサスA&M大学
＜関連情報＞
- https://stories.tamu.edu/news/2025/09/24/battery-made-from-natural-materials-could-replace-conventional-lithium-ion-batteries/
- https://www.pnas.org/doi/10.1073/pnas.2509325122
持続可能なエネルギー貯蔵材料としての、生物に着想を得た分解性リボフラビン含有ポリペプチドA bioinspired and degradable riboflavin-containing polypeptide as a sustainable material for energy storage
Shih-Guo Li, Khirabdhi T. Mohanty, Alexandra D. Easley, +7 , and Karen L. Wooley
Proceedings of the National Academy of Sciences Published:June 23, 2025
DOI:https://doi.org/10.1073/pnas.2509325122
Significance
Sustainable energy storage materials can address environmental, safety, security, and ethical issues associated with conventional battery platforms. Herein, we advance the design of redox-active polypeptide materials by incorporating riboflavin, a biological redox cofactor, as redox-active pendant groups on a hydrolytically degradable polyglutamate backbone. This design retains the polypeptide backbone architecture while introducing renewable side-chain functionality, enabling the construction of a biologically sourced organic battery material. The resulting design improved sustainability, minimized cytotoxicity, and demonstrated effective degradability under hydrolytic conditions. By decoupling redox activity from fossil-based feedstocks or metals, this bioinspired strategy introduces a class of environmentally friendly materials for next-generation energy storage systems (ESSs).
Abstract
Inspired by Nature, we present a polypeptide-based organic redox-active material constructed from renewable feedstocks, L-glutamic acid (an amino acid) and riboflavin (vitamin B2), to address challenges with start-to-end-of-life management in energy storage systems (ESSs). The amino acid was utilized to establish a degradable polymer backbone, along which many copies of riboflavin were incorporated to serve as the redox-active pendant groups that enabled energy storage. The overall synthesis involved the ring-opening polymerization (ROP) of an l-glutamic acid-derived N-carboxyanhydride (NCA) monomer, followed by side chain activation with azides and, finally, click coupling to achieve installation of alkyne-functionalized riboflavin moieties. The steric bulkiness and rich chemical functionality of riboflavin resulted in synthetic complexities that required reaction optimization to achieve the desired polymer structure. Electrochemical characterization of the resultant riboflavin polypeptide, in organic electrolyte, showed quasireversible redox activity with a half-wave potential (E1/2) of ca. −1.10 V vs. ferrocene/ferrocenium (Fc/Fc+). Cell viability assays revealed biocompatibility, as indicated by negligible cytotoxicity for fibroblast cells. The polypeptide design, consisting of labile amide backbone linkages and side-chain ester functionalities that tethered the riboflavin units to the backbone, enabled hydrolytic degradation to recover building blocks for future upcycling or recycling. This bioinspired strategy advances the development of degradable redox-active polymers and promotes sustainable materials design for circular energy storage technologies.
