Dr Mahdokht Shaibani

NEW LITHIUM-SULPHUR BATTERY; HIGHER PERFORMANCE, CHEAPER AND GREENER

By Ms Nancy Van Nieuwenhove | 3rd March 2020 (update* 23/07/2020)

Dr Mahdokht Shaibani

Research Fellow, Mechanical & Aerospace Engineering

Research interests: battery, energy storage systems, climate change, sustainable manufacturing, environmental engineering, metal composites, materials synthesis, lithium-sulphur batteries, flow batteries, supercapacitors, and lithium-ion capacitors

Dr Mahdokht Shaibani was born in Shiraz, Iran. She spent most of her childhood in her grandparent’s house, where she found some of her favourite books (Jules Verne and Isaac Asimov) “The practicality of the science fiction stories in those books and the awareness of Verne and Asimov of the theoretical limitations of the fiction technologies they wrote about contributed a lot in the engineer that I am today”.

From young age, Mahdokht knew the key to improving our everyday technologies was linked to new materials or new processing techniques to make available materials perform better. That’s why she followed a material engineering degree. Mahdokht holds a bachelor’s in Materials Engineering from Shiraz University and a master’s in Materials Engineering from University of Tehran. With a metallurgy background, she didn’t suspect she would ever join the energy sector and didn’t work on energy-storage materials or devices until her PhD. “I was offered scholarships with different universities and on subjects from computational studies to pharmaceuticals and energy storage. I wanted to work on something that the general public could relate to and have an immediate impact on their daily lives. That’s why I choose the PhD project at Monash”.

Mahdokht completed a PhD at Monash in 2017, in collaboration with CSIRO, on advanced electrochemical energy storage devices and carbon-based supercapacitors. She immediately discovered she truly enjoyed improving the performance metrics of batteries. “I choose to work on lithium sulphur battery (Li-S) as there is no limit in achieving better performance or using more sensible materials, or more practical designs. I was extremely lucky to work under amazing supervision: Prof Mainak Majumder (Monash Mechanical and Aerospace Engineering) is a globally renowned scientist, who has had an exceptional influence on my career. I learned that if we want our fundamental discoveries to be translated to real life environment from industry to market, practicality should always be in the experimental design. I’m still learning about leadership skills from Australia’s influential science leader A/Prof Matthew Hill (Monash and CSIRO) and am further developing my scientific thinking and reasoning skills from the discussions with former co-supervisor Dr Tony Hollenkamp (CSIRO)”.

From left to right: A/Prof Matthew Hill, Dr Mahdokht Shaibani and Prof Mainak Majumder (Photo credits Monash University)

Her PhD was followed by postdoctoral research. That’s when she discovered how to create the most efficient Li-S battery. “In the final year of my PhD, I turned a part of my thesis into a patent for a new design of battery. The company invested in the research and helped to fund my research fellowship and the establishment of a battery prototyping lab at Monash University. Back then, it was only me, Matt and Mainak. Now, we have 4 PhD students, Postdocs, and we are moving towards the commercialisation project of the new Li-S battery”.

Graph listing the theoretical energy density of some currently used batteries such as Li-ion and some of the currently explored ones such as Li-S (Dr Mahdokht Shaibani).

What are the differences between Lithium-ion batteries (Li-ion) and Lithium sulphur (Li-S) batteries? For Mahdokht, there are 3 main differences: the first one is the performance – all sectors want batteries with more power and a better cycle life. Li-S battery offers 4 to 5 times improvement compared to Li-ion in the energy density (on paper), so we can expect 2 or 3 times increase in the energy density (in practice). The second difference is material availability and pricing – certain materials are easily available; others are getting scarce making them expensive and unreliable in terms of exploitation. With Li-ion battery, there are ethical concerns around the sourcing of the materials required, such as Cobalt (which is predicted to be more difficult to source in the future). In comparison, Li-S batteries use lithium and sulphur electrodes, so do not require rare or heavy metals and sulphur can be found pretty much anywhere on earth which make it inexpensive (US$100 per tonne). Also, our patented electrode processing for Li-S batteries (PCT/AU2019/051239) is completely water-based, with no need for toxic hazardous solvents often used in Li-ion battery manufacturing. The third difference is the cost of production of Li-S batteries estimated to be 4 to 8 times less than Li-ion battery.

Monash University Lithium-sulphur battery prototype (Dr Mahdokht Shaibani).

Dr Mahdokht Shaibani is leading the scale-up manufacturing and commercialisation lithium-sulphur battery project between diverse research, industry, and R&D partners. “Since day one, I knew that no manufacturer was going to shut-down their manufacturing line and create a new one for me. We needed to use the same fabrication method used in the battery industry and the same commercially available materials as the price was going to be a governing factor. As material scientist, I am not as excited to synthesise the material, because even if the device the battery works perfectly fine, the scale-up of that synthesis could take years and may never be cost-effective”.

The Lithium-sulphur battery prototypes built with the researchers' electrodes maintain 99 percent efficiency for over 200 charging cycles. The next prototypes have been successfully fabricated by German R&D partners Fraunhofer Institute for Material and Beam Technology. The team is also wanting to explore the use of Li-S batteries for more sustainable and clean transportation and grid storage. Last year in June, they teamed up with Monash Motorsport to explore the use of Li-S batteries in electric vehicles. Mahdokht mentions that "today’s EV batteries are an important part of the total EV cost (33% to 57% depending on the car) and EV weight (20% to 25%). Lighter batteries would result in higher EV range; and a low-cost lighter battery means the EV manufactures could, if interested, explore new car concepts like allocating more car space to the battery pack without having cost and weight concerns!".

Everything is moving towards being battery-powered, portable electronics, smart watch, cell phones, indispensable devices we use in our daily lives. Mahdokht mentions “Hunger for energy has reached a scary level, not for the users but for the players of the energy sector. Who doesn’t want to drive an E.V? Who doesn’t want to have a big battery to their residential solar plan to save on electricity bills? It is a critical time to explore alternative battery technologies. What I would like to see in the next years is more collaboration between governments, industries and universities to lead the change and take major steps towards cleaner batteries!"

For further information:

https://www.linkedin.com/in/mahdokht-shaibani-29868440/?originalSubdomain=au

Scientific Paper:

Mahdokht Shaibani, Meysam Sharifzadeh Mirshekarloo, Ruhani Singh, Christopher D. Easton, M. C. Dilusha Cooray, Nicolas Eshraghi, Thomas Abendroth, Susanne Dörfler, Holger Althues, Stefan Kaskel, Anthony F. Hollenkamp, Matthew R. Hill, Mainak Majumder (2020) “Expansion-tolerant architectures for stable cycling of ultrahigh-loading sulphur cathodes in lithium-sulphur batteries” Science Advances doi: 10.1126/sciadv.aay2757

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