Presentation Title: Columnar Structured Ni-rich Cathode Materials for Next-Generation Lithium Batteries

Abstract：

To achieve carbon neutrality, the widespread adoption of electric vehicles (EVs) is driving the demand for next-generation lithium-based batteries with higher energy density, improved safety, and longer lifespan. All-solid-state batteries (ASSBs) employing LiMO₂(M = Ni, Co, Mn, and/or Al, Ni ≥ 80%) cathode active materials (CAMs) are considered promising candidates due to their high reversible capacities. However, Ni-rich CAMs suffer from structural and interfacial degradation, which is exacerbated when combined with sulfide-based solid electrolytes in ASSBs. Challenges include severe parasitic reactions at the CAM/electrolyte interface due to chemical incompatibility and electrochemical instability, and mechanical degradation such as particle isolation and CAM–electrolyte detachment, which intensifies with increasing Ni content.

In this presentation, to overcome the trade off relationship between reversible capacity and cycling stability of NCM cathode, an approach is to develop radially aligned primary particles with crystallographic texture by Nb doping in Ni-rich layered cathodes. The Nb-doped Ni-rich cathode not only induces the surface coating layer on cathode particle surface but also produces radially oriented primary particles, demonstrating good long-term cycling performances.

Furthermore,we systematically evaluated the degradation mechanisms of Ni-rich Li[Ni_xCo_yAl_1-x-y]O₂ cathodes in sulfide-based ASSBs using a series of CAMs with controlled surface and morphology modifications across a wide range of Ni contents (80–95%). Quantitative comparisons among pristine, surface-modified, morphology-modified, and dual-modified CAMs revealed that surface degradation dominates at 80% Ni content, while particle isolation and interfacial detachment become significant at 85% and above. Based on the deep understanding of the capacity fading mechanisms of Ni-rich CAMs in ASSBs and the contribution of each capacity fading factor, we also propose future research strategies for developing high-performance ASSBs.

Bio

YANG-Kook Sun, a member of the Korean Academy of Engineering and a professor at Hanyang University, is primarily engaged in research on advanced energy storage materials and lithium-ion batteries. He has made significant contributions to the commercialization of lithium-polymer batteries and proposed the concept of layered concentration-gradient cathode materials for lithium-ion batteries. His research focuses on the development of cathode materials for power batteries, including the capacity fade mechanisms of high-nickel cathodes, the design of concentration-gradient structures, and microstructural control through ion doping. His team has achieved groundbreaking progress in the field of power batteries for new energy vehicles, with relate (results/achievements) having been applied to commercial production.