It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, September 20, 2024
Charging ahead towards future low-cost polymer zinc-ion batteries
More sustainable solutions for future power sources
With global demand for lithium-ion batteries fast depleting reserves of raw materials, experts are seeking safe, affordable and reliable alternatives for rechargeable batteries.
Aqueous zinc-ion batteries (AZIBs) could be the answer to producing low-cost alternatives from abundant feedstocks, and Flinders University scientists are paving the way for the production of simple and practical polymer AZIBs using organic cathodes for more sustainable energy storage technology.
“Aqueous zinc-ion batteries could have real-world applications,” says Associate Professor in Chemistry Zhongfan Jia, a nanotech researcher at the College of Science and Engineering at Flinders University.
From electric vehicles to portable electronic devices, the demand and consumption of lithium-ion batteries (LIBs) have led to resource shortages and supply-chain issues of strategic metals including lithium and cobalt.
Meanwhile, millions of spent batteries, most of which are not properly recycled, have caused enormous waste and environmental risks - which future alternatives such as AIZBs promise to reduce.
“Among these alternatives, AZIBs stand out because of the much higher abundance of zinc in the earth's crust (ten times more than lithium), and their low toxicity and high safety.”
AZIBs usually use zinc metal as an anode and inorganic or organic compounds as a cathode. While substantial work has been devoted to improving the stability of zinc anodes, high-performing cathodes are needed and remain a major challenge.
“Our research is building conductivity using nitroxide radical polymer cathodes made from cheap commercial polymer and optimised the battery performance using low-cost additives,” says Associate Professor Jia, who leads a research group working on Sustainable Polymers for Energy and Environment.
“Our work reevaluated the use of high redox potential nitroxide radical polymers cathodes in AZIBs, and produced the highest mass loading so far,” he says, about a new online journal article in the Journal of Power Resources.
The study, led by Flinders master student Nanduni Gamage and postdoc fellow Dr Yanlin Shi, developed a lab-made pouch battery using scaled-up polymer (at approx. cost $20 / kg), a non-fluoro Zn(ClO4)2 electrolyte, and BP 2000 carbon black ($1 / kg) without binder to provide a capacity of nearly 70 mAh g-1 and a middle discharge voltage of 1.4 V.
With a mass loading of 50 mg cm-2, the pouch battery had a capacity of 60 mAh, which can easily power a small electric fan and a model car (see videos in the article).
Collaborators in the study, including Dr Jesús Santos-Peña, from the Université Paris Est Creteil CNRS in France, worked with other experts from the Flinders University Institute for Nanoscale Science and Technology.
In collaboration with Griffith University, the team has also recently developed organic radical/K dual-ion batteries, a technique that can also relieve dependence on lithium-ion batteries.
Acknowledgements: This project is supported by funding from the Australian Research Council (DP230100587, DP230100642, LE230100168) and the French-Australian International Research Network on Conversion and Energy Storage (IRN-FACES). The authors also acknowledge the Australian National Fabrication Facility (ANFF) SA node for supporting the electroanalytical and electrochemical synthesis labs at Flinders University.
Converting a low-cost industrial polymer into organic cathodes for high mass-loading aqueous zinc-ion batteries
New 'PVDF alternative battery binder' surpasses EU environmental regulations!
National Research Council of Science & Technology
image:
The research results of KERI's 'PVDF Replacement Battery Binder Technology' have been published as the cover article in the prestigious journal ‘Advanced Functional Materials’.
Credit: Korea Electrotechnology Research Institute
A team led by Dr. Hyeon-Gyun Im and Dr. Dong Jun Kang from the Insulation Materials Research Center of Korea Electrotechnology Research Institute (KERI), in collaboration with Dr. Jung-keun Yoo from KIST and Professor Jong-soon Kim from Sungkyunkwan University, have developed a technology that enhances the performance of binders—often the 'unsung heroes' in the field of secondary batteries—while using environmentally friendly materials. This technology has been published in a prestigious international journal.
The electrode, which has the greatest impact on the performance of secondary batteries, is manufactured by mixing an 'active material' that generates electricity, a 'conductive material' that facilitates the flow of electricity, and a 'binder' with a solvent. The role of the binder is to help the active material and conductive material adhere well to the metal plate (current collector) and to physically stabilize the electrode.
The binder has a relatively small proportion in the electrode, which has led to slower research progress in the past. However, with the increasing demand for high-capacity and high-performance batteries, interest in binders is growing. Currently, Polyvinylidene Fluoride (PVDF), a fluoropolymer material, is predominantly used as the binder material for lithium-ion battery positive electrodes. However, PVDF is dominated by some global companies in Japan and Europe, and there have been ongoing functional issues, such as decreased battery stability, associated with its use.
Specifically, PVDF is composed of a very strong carbon-fluorine (C-F) bond and is almost indestructible in nature, earning it the nickname 'zombie compound.' Due to its difficulty in decomposition, it remains in the environment for extended periods and is known to emit significant amounts of greenhouse gases when burned. Due to these environmental concerns, the European Union (EU) is considering regulating the use of PVDF. Therefore, the development of binder materials that surpass PVDF is extremely urgent.
KERI has addressed this issue by applying 'siloxane' to positive electrode binders. Siloxane is a compound composed of silicon and oxygen, known for its excellent electrical properties and chemical stability. Dr. Hyeon-Gyun Im and Dr. Dong Jun Kang’s team has secured a 'hybrid siloxane resin manufacturing technology' that combines the advantages of both organic and inorganic materials* through years of research on nanocomposites. They have also developed molecular structure design and synthesis control technologies applicable to positive electrode binders. * Organic and Inorganic Materials: In chemical structure, if a material lacks carbon atoms, it is classified as inorganic; if it contains carbon atoms, it is classified as organic. Inorganic materials are known for their strength and durability, making them suitable for use in aircraft parts and construction materials. Organic materials, due to the numerous bonds formed by carbon atoms, have complex molecules and exhibit a variety of physical properties (such as resistance and elasticity). Because of these characteristics, organic materials are widely used in electronics, clothing, and other products.
The research team conducted multiple validations by producing full cells using the applied technology. As a result, it was confirmed that the KERI technology exhibits over 1.4 times higher lifespan stability compared to conventional binders with PVDF. While PVDF is known for its physical and chemical stability and good adhesion properties, it has faced issues such as swelling and unwanted side reactions between internal materials as batteries have progressed toward higher capacity and performance. However, KERI's technology has surpassed these limitations.
The major advantage of this achievement is that it does not contain fluorine, making it environmentally friendly and safe for human health. The new technology is expected to not just avoid the EU's environmental regulations aimed at limiting the use of PVDF but significantly contribute to reducing the reliance on imported positive electrode binders.
Dr. Hyeon-Gyun Im from KERI stated, "While Korea’s battery industry is world-class, we currently rely entirely on imports for positive electrode binders due to the lack of specialized technology and companies domestically. Our environmentally friendly binder technology using siloxane has the potential to replace existing PVDF and enhance the safety and lifespan of products requiring high-capacity batteries, such as electric vehicles."
Additionally, the research results have been recognized for their excellence and were recently published as a back cover article in the prestigious journal ‘Advanced Functional Materials’. The “JCR Impact Factor” of the journal is 18.5, ranking in the top 5% of the field.
The research team anticipates that this achievement will attract significant interest from the secondary battery industry and plans to identify potential demand partners to facilitate technology transfer. Furthermore, they plan to apply the developed technology to dry positive electrode binder materials and continue research to extend its use to various areas, including zinc batteries and sodium batteries.
KERI has developed a battery positive electrode binder that can replace PVDF using siloxane.
KERI researchers are developing a battery positive electrode binder that can replace PVDF using siloxane.
Credit
Korea Electrotechnology Research Institute
<KERI is a government-funded research institute under the National Research Council of Science & Technology of the Ministry of Science and ICT.>
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