Presentation Title: Mechanically and Chemically Co-Robust Ni-Rich Cathodes with Ultrahigh Capacity and Prolonged Cycle Life

Abstract: 

   Lithium-ion batteries (LIBs) have been widely applied in electric vehicles, unmanned aerial vehicles, and mobile robots owing to their high specific energy and long cycle life. As the key components of LIBs, cathode and anode materials directly govern the battery performances. Layered oxides are the widely used cathode materials. However, Ni-rich layered oxide cathodes suffer from mechano-electrochemical failure during charging, which degrades the cycling performance and shortens the battery lifespan. To address this issue, we effectively enhance the mechano-electrochemical stability of Ni-rich layered oxide cathodes through high-valence niobium (Nb) doping. By combining scanning transmission electron microscopy (STEM), density functional theory (DFT) calculations, and electrochemical measurements, we reveal that Nb doping strengthens the Nb-O bonding and mitigates the structural strain during delithiation, thereby improving the stability of Ni-rich cathodes. On the anode side, in situ electron microscopy demonstrates that the carbon-coated Nb₂O₅ anode effectively homogenizes Li-ion and electron transport, which improves the (de)lithiation kinetics and cycling performance of Nb₂O₅ anode. These studies on Nb in both cathode and anode materials highlight its promising application prospects in lithium-ion batteries. 

Biography: 

    Yongfu Tang is a Professor and Ph.D. supervisor at Yanshan University and a recipient of the National High-level Young Talent Program of China. His research is focused on the design and development of high-performance electrochemical energy storage devices, including solid-state batteries and sodium-ion batteries, as well as their characterization by in situ and cryogenic electron microscopy. In recent years, he has presided over more than 20 research projects, including grants from the National Natural Science Foundation of China (NSFC), the Hebei Provincial Science Fund for Distinguished Young Scholars, and industry-commissioned projects. His honors include the "Young Top-notch Talent" of Hebei Province, and the Third Prize of the Hebei Provincial Natural Science Award (ranked first). As first or corresponding author, he has published over 120 papers in high-impact journals such as Nat. Nanotechnol., Nat. Commun., Adv. Mater., Angew. Chem. Int. Ed., and Energy Environ. Sci. His publications have been cited more than 6,000 times by other researchers, with an h-index of 44. He has filed over 20 national invention patent applications, more than 10 of which have been granted.