Periodic Reporting for period 1 - BIOSIC (Biopolymer based Single-Ion Conducting Gel Polymer Electrolytes for Highly Performant and more Sustainable Batteries)
Berichtszeitraum: 2021-09-01 bis 2023-08-31
Today’s lithium (Li)-ion batteries play an important role in our society; they are everywhere in our daily life from our smartphones, laptops, and E-bikes to our electric cars. However, the rapidly growing Li-ion battery industry places high pressure on raw materials production such as Li, cobalt, and nickel - needed for electrode preparation. These materials are not only scarcer but also not globally distributed, posing significant geopolitical issues. Furthermore, Li-ion battery accidents have recently become more common, which is closely related to the electrolyte composition. To properly ensure safe batteries, the development of safer and more environmentally-friendly ‘green’ electrolytes is urgently needed. The research aim of this project is to create performant sustainable electrolytes from bio-sourced, abundant, reliable and low-cost materials. This project addressed electrolyte design and development of aqueous Zinc-ion battery (ZIB) – a highly promising battery chemistry for large-scale applications. Indeed ZIBs have the capability to revolutionize the energy storage industry, due to their cost and scalability compared to Li-ion technology. However, a significant challenge facing ZIB technology lies in their limited compatibility of Zn anode with conventional aqueous electrolytes. This issue primarily stems from the undesired water decomposition that occurs during the zinc plating process during battery cycling.
More precisely, the primary innovation of this project lies in the creation of sustainable electrolytes, presented in the form of gel biopolymers and aqueous liquid electrolytes, surpassing the capabilities of existing electrolytes. The gel polymer, derived from a charged chitin polymer, demonstrates significant enhancements of Zn metal stability. Additionally, the developed aqueous eutectic electrolytes not only enhance battery performance but also exhibit compatibility improvement with various battery components. Furthermore, the approach of this electrolyte, based on the Brønsted-Lowry concept, exhibits versatility with different types of salts. This work presents an efficient, simple, and low-cost strategy for the development of aqueous electrolytes for the practical application of zinc batteries.
More precisely, the primary innovation of this project lies in the creation of sustainable electrolytes, presented in the form of gel biopolymers and aqueous liquid electrolytes, surpassing the capabilities of existing electrolytes. The gel polymer, derived from a charged chitin polymer, demonstrates significant enhancements of Zn metal stability. Additionally, the developed aqueous eutectic electrolytes not only enhance battery performance but also exhibit compatibility improvement with various battery components. Furthermore, the approach of this electrolyte, based on the Brønsted-Lowry concept, exhibits versatility with different types of salts. This work presents an efficient, simple, and low-cost strategy for the development of aqueous electrolytes for the practical application of zinc batteries.
The project results in the development of two sustainable electrolytes for aqueous Zinc-ion batteries - Zwitterionic chitin gel-polymer and aqueous eutectic-based electrolytes:
1. Gel-polymer electrolyte: a novel gel polymer electrolyte has been developed, serving the dual function of both electrolyte and separator. The zwitterionic chitin polymer demonstrates remarkable mechanical properties and compatibility with the Zn anode. The gel polymer electrolyte shows a boost is Zn cycling stability from 200 cycles in glass and cellulose separators to 2000 cycles. This collaborative effort involves an expert in biopolymers, specifically cellulose and chitin. Ongoing analyses are underway, and we anticipate that the results will bring about a revolutionary advancement in the field. The obtained results are aimed to be published in the form of a scientific paper.
2. Aqueous eutectic electrolyte: we reported in this project an aqueous eutectic electrolyte (AEE) based on Brønsted–Lowry concept – allowing the usage of cheap and abundant salts, ZnCl2 and sodium acetate. The reported, pH buffered, AEE displays a higher coordination of water at an even lower salt concentration, by simply balancing the acceptor–donor H–bonding. This results in impressive improvement of electrolyte properties such as high electrochemical stability, high transport properties and low glass transition temperature. The developed AEE displays higher compatibility with vanadium oxide-based cathode with a 50 % increase in capacity retention in comparison to sat. ZnCl2. More importantly, the pH buffered AEE solves the incompatibility issues of ZnCl2 towards commonly used Aluminum (Al) current collector as well as cellulose separator.
The obtained results are available in the published paper in Small journal: R. Bouchal*, I Al Kathemi and Markus Antonietti*. Brønsted–Lowry Acid-Based Aqueous Eutectic Electrolyte for Practical Zinc Batteries. Small, 2023, 2309556. DOI: 10.1002/smll.202309556.
1. Gel-polymer electrolyte: a novel gel polymer electrolyte has been developed, serving the dual function of both electrolyte and separator. The zwitterionic chitin polymer demonstrates remarkable mechanical properties and compatibility with the Zn anode. The gel polymer electrolyte shows a boost is Zn cycling stability from 200 cycles in glass and cellulose separators to 2000 cycles. This collaborative effort involves an expert in biopolymers, specifically cellulose and chitin. Ongoing analyses are underway, and we anticipate that the results will bring about a revolutionary advancement in the field. The obtained results are aimed to be published in the form of a scientific paper.
2. Aqueous eutectic electrolyte: we reported in this project an aqueous eutectic electrolyte (AEE) based on Brønsted–Lowry concept – allowing the usage of cheap and abundant salts, ZnCl2 and sodium acetate. The reported, pH buffered, AEE displays a higher coordination of water at an even lower salt concentration, by simply balancing the acceptor–donor H–bonding. This results in impressive improvement of electrolyte properties such as high electrochemical stability, high transport properties and low glass transition temperature. The developed AEE displays higher compatibility with vanadium oxide-based cathode with a 50 % increase in capacity retention in comparison to sat. ZnCl2. More importantly, the pH buffered AEE solves the incompatibility issues of ZnCl2 towards commonly used Aluminum (Al) current collector as well as cellulose separator.
The obtained results are available in the published paper in Small journal: R. Bouchal*, I Al Kathemi and Markus Antonietti*. Brønsted–Lowry Acid-Based Aqueous Eutectic Electrolyte for Practical Zinc Batteries. Small, 2023, 2309556. DOI: 10.1002/smll.202309556.
The findings will have a significant impact on the practical application of zinc batteries. The beneficiary addressed the Zinc anode stability issue by reporting high-performing aqueous electrolytes and more stable polymer-based electrolytes. Furthermore, the combination of the reported aqueous eutectic electrolyte and the polymer separator is expected to improve stability even further. Achieving high stability by developing a more compatible electrolyte and separator with zinc electrode will be crucial for future zinc-ion battery applications.