Graduate Student Spotlight: Yi-Ting Cheng Publishes First-Author Paper with International Research Team
Yi-Ting Cheng is a third-year PhD student in the Chris Bartel research group whose work focuses on the computational design of battery materials. Recently, she published her first first-author paper, Synthesis, Electronic Structure, and Redox Chemistry of Li₂MnP₂S₆, a Candidate High-Voltage Cathode Material. The study is the result of an exciting collaboration with Hokkaido University’s Prof. Miura and his experimental group in Japan. In this Q&A, Yi-Ting shares insights into her groundbreaking research, the challenges and rewards of bridging computation and experiment, and how this experience has shaped her path as a researcher.
Q: What is the focus of your recent paper, and what makes it significant?
Our study, in collaboration with Prof. Miura's group, focuses on the synthesis and redox mechanisms of lithium manganese thiophosphates (Li₂MnP₂S₆). Experimental results revealed that Li₂MnP₂S₆ and Li₂FeP₂S₆ exhibit similar voltages, often indicative of analogous redox mechanisms. However, our computational analysis uncovered a surprising distinction: while Li₂FeP₂S₆ relies on Fe redox activity for charge compensation, the substitution of Fe with Mn in Li₂MnP₂S₆ activates an unexpected anionic S redox mechanism. This provides new insights into thiophosphate cathodes and highlights their potential for high-capacity Li-ion batteries.
Q: How did the collaboration with the experimental group in Japan come about?
The collaboration began through a longstanding relationship between my advisor, Prof. Bartel, and Prof. Miura, who worked together during my advisor's postdoctoral research. When Prof. Miura’s group successfully synthesized this new material, they invited us to explore it further using computational methods. It’s been incredibly rewarding to see how theory and experiment work hand in hand—our computational predictions about redox mechanisms were validated through experimental techniques like spectroscopy.
Q: What challenges or memorable moments stand out from the collaboration?
At first, it was challenging to integrate the experimental findings with our computational results and communicate effectively with the experimental team. Bridging the gap between theory and experiment took time and mutual learning. However, as the project progressed, I gained a deep appreciation for how these approaches complement each other. Seeing our predictions confirmed was particularly exciting.
Q: How has this research influenced your growth as a graduate student?
This project led to my first first-author paper, which has been a major milestone in my PhD journey. It allowed me to develop my computational skills, collaborate with experimental researchers, and experience the full process of scientific discovery—from initial ideas to publication. It has strengthened my technical expertise and improved my ability to communicate research findings, which will serve me well in my future career.
Q: How will this paper shape your future research direction?
This work establishes a framework for understanding redox mechanisms in sulfide materials through computational tools. Moving forward, I aim to refine these methods to better connect solid-state structures to battery properties. This will help guide the design of next-generation sulfide cathode materials and aligns with my long-term goal of contributing to battery development.
Q: Are there ongoing or future projects stemming from this research?
Yes, we’re continuing our collaboration with Prof. Miura’s group to explore other sulfide cathode materials and their atomic environments. Unlike commercial oxide cathodes, sulfide materials present open questions about their redox mechanisms and structural changes during cycling. I’m eager to study how these factors influence performance and hope to unlock new pathways for optimizing sulfide-based battery materials.
Congratulations to Yi-Ting on this exciting achievement! She is the past recipient of both the Dr. Doraiswami and Mrs. Geetha Ramkrishna Fellowship in Chemical Engineering and the Arnie Fredrickson Fellowship.
If you’d like to read the full paper, Synthesis, Electronic Structure, and Redox Chemistry of Li₂MnP₂S₆, a Candidate High-Voltage Cathode Material, you can find it at the Chemistry of Materials digital platform.