By summer student Qiujing Gou >

As society transitions toward large-scale adoption of green energy, we need high-performance batteries to store electricity. Lithium-sulfur (Li-S) batteries, owing to their high theoretical energy density (>1000 Wh/kg vs. approximately 250 Wh/kg for state-of-the-art lithium-ion batteries) and the low-cost and abundance of sulfur, are considered to be one of the most promising technologies for next-generation energy storage solutions.

My research at HZB

During the summer school at HZB, I investigated a novel water-based biopolymer binder, chitosan for the sulfur cathode. Chitosan, made from seafood waste, is an eco-friendly material. Through modification, it becomes water-soluble and more suitable for lithium-sulfur batteries. Additionally, at HZB I learned the cathode production including slurry formulation, electrode coating, calendaring and assembly of lithium-sulfur batteries and electrochemical testing. Then, I prepared the cathodes using commercial binders and my developed aqueous chitosan binder, tested and compared their electrochemical performances. By step-by-step optimization, from binder design, to binder synthesis, electrode production and battery assembly, the as-developed aqueous chitosan binder exhibit excellent performances for lithium-sulfur batteries.

Throughout this research journey, I’ve learned a lot along the way

My mentor, Prof. Yan Lu, always pointed out key questions in my research, helping me to inspire  my crucial and scientific thinking, and help me to make experimental plan effectively. The senior researchers at the lab provided valuable advice and assistance, emphasizing the importance of details like every parameter and process of the slurry formulation. I feel incredibly fortunate to study with such supportive mentors and lab members, and therefore I aspire to be an outstanding researcher.

Research environment at HZB and daily life during summer school

This trip to Berlin has not only allowed me to delve deep into the research of lithium-sulfur batteries but also to experience the plentiful and vibrant research environment. At HZB, I participated in a science communication workshop, where I learned valuable skills for conveying complex scientific concepts to the public. Additionally, I took part in a guided tour of the facility for eye tumor therapy, which gave me an up-close look at cutting-edge medical technologies and their impact on people’s lives.

Living in Berlin added a unique layer of richness to this experience. During weekdays, I immersed myself in the dynamic research culture. For instance, during lunchtime every day, we would sit together with Prof. Yan Lu and the group to talk about everything from the latest research breakthroughs to news and funny anecdotes from our daily lives. In addition, during the summer, my summer school students and I watched the European Cup together, bonding over a shared love of soccer and science.

On weekends, we often explored the city’s rich history and cultural heritage by visiting museums. We also made time to keep fit by going to the gym, which helped us stay energized and focused throughout our busy days. Cooking together in the student apartment with roommates from different countries and cultures was particularly warm and enriching. Sharing recipes and stories from our respective backgrounds led to many interesting conversations and a deeper understanding of each other.

As the summer school draws to a close, I find myself increasingly grateful for the time spent here, and I know that the memories and friendships formed will last a lifetime.

About the Author: My name is Qiuying Gou, and I am currently a second-year graduate student at Donghua University in Shanghai, China. At the Helmholtz-Zentrum Berlin (HZB), my research focuses on the design and synthesis of a bio-based, water-soluble binder for lithium-sulfur batteries.