Presentation Title: The Possible Mechanism of Nb Element on Improving Layered Cathode Materials for Li-ion Battery

Abstract: 

     Interfacial stability and bulk structural integrity of layered cathode materials are core factors restricting their electrochemical performance. As an effective modifier, niobium plays an extremely important role in lithium-ion layered cathode materials; nevertheless, its modification mechanism remains insufficiently clarified. In this report, a detailed discussion on the mechanism by which niobium improves the performance of layered cathode materials is presented: 

     1. In the conventional liquid LiCoO₂ system, it is found that niobium sources react with the matrix during heat treatment to generate diverse interfacial phases. When a triphase composite interface consisting of LiNbO₃/Li₃NbO₄/Co₃O₄ is constructed, the stability of liquid-state batteries can be effectively enhanced. However, when this strategy is applied to sulfide-based all-solid-state batteries, the newly formed Co₃O₄ deteriorates the interfacial properties between the cathode and sulfide electrolyte, leading to rapid degradation of battery performance. 

    2. The niobium modification strategy is extended to nickel-rich cathode materials for sulfide solid-state batteries. It is revealed that temperature-tuned interfacial phases differ from those in the LiCoO₂ system. The in-situ formation of a three-dimensional superionic conductive Li₃NbO₄ layer remarkably boosts the electronic conductivity and interfacial compatibility of NCM811, and elevates the cycling stability of the material under high voltages. 

     3. High-valence elements including Nb, W, Ta and Mo suffer from inherent solubility limitations when employed for doping modification of layered cathodes. Accordingly, only trace doping can be achieved, while the residual species precipitate between primary particles of polycrystalline ternary cathodes to form a coating layer in situ. This realizes a triple synergistic effect: limited bulk doping, inter-primary-particle segregation and secondary-particle surface coating. 

    This work systematically uncovers the formation mechanism of niobium-derived interfacial phases in layered materials and distinguishes the behavioral differences between liquid and solid-state battery systems, offering viable design strategies for interfacial modification of high-performance cathode materials.

Biography: 

    Prof. Dr. Zhang Lianqi currently serves as the Director of the Office of Science and Technology, Professor at the School of Materials Science and Engineering, Dean of the Institute of Advanced Technology, and Director of the Technology Transfer Center at Tianjin University of Technology. He also leads the Advanced Power Batteries and Energy Storage Technology research group. He obtained his B.Sc. in Chemistry from Shandong Normal University in 1996, his M.Sc. in Physical Organic Chemistry from the Institute of Chemistry, Chinese Academy of Sciences, in 1999, and his Ph.D. in Applied Chemistry from Saga University, Japan, in 2003. From April 2003 to June 2008, he engaged in postdoctoral research successively at the National Institute for Materials Science (NIMS) and Tokyo Institute of Technology in Japan. From June 2008 to October 2010, he held the position of Senior Engineer at the Key Laboratory of Physical and Chemical Power Sources, the 18th Research Institute of China Electronics Technology Group Corporation. He joined Tianjin University of Technology as a Professor in November 2010, was appointed Deputy Director of the Office of Science and Technology in November 2020, and has been serving as Director of the Office of Science and Technology since March 2026. His research interests primarily focus on advanced materials for high-specific-energy secondary batteries and solid-state battery technologies. In the domain of high-energy cathode materials, he pioneered strategies including multi-shell core-shell structural design and gradient elemental doping, which effectively mitigate voltage decay and anionic oxygen release during high-voltage cycling. In the field of solid-state electrolytes, he has systematically investigated the molecular engineering of polymer electrolytes and elucidated the mechanistic role of anion-rich solvation structures in facilitating rapid Li⁺ transport, while also accumulating substantial expertise in the stabilization of solid-solid interfaces for sulfide-based solid-state batteries. Furthermore, he has been at the forefront of developing recycling technologies for spent lithium-ion power batteries in China, establishing an integrated research framework encompassing cathode materials, electrolytes, interface engineering, and battery lifecycle management. His scholarly achievements have been recognized through numerous honors: he was named a New Century Excellent Talent by the Ministry of Education in 2010, selected as a First-Level Talent of the Tianjin "131" Innovative Talent Training Program in 2011, appointed as a Tianjin Distinguished Professor in 2012, designated as a Tianjin University Discipline Leading Talent in 2017, and honored as a Tianjin Outstanding Jinmen Scholar in 2019. In 2025, he received the First Prize of the Tianjin Science and Technology Progress Award (ranked 3rd among the awardees). He has led his research team in undertaking over ten nationally funded projects, including those under the Military 973 Program, the National Key R&D Program, the National 863 Program, and the National Natural Science Foundation of China, with cumulative research funding exceeding RMB 40 million. He has published over 200 peer-reviewed SCI papers as the corresponding author in prestigious journals including Angew. Chem. Int. Ed., Adv. Mater., and Energy Environ. Sci., and holds over 30 authorized invention patents, of which 10 have been successfully commercialized.