锂离子电池中重要正极材料体系的磁共振研究进展

Lithium-ion batteries have grown rapidly and have changed our lives. The research on the cathode materials of lithium ion battery is the key to improve the performance of the battery. Therefore, understanding the relationship between the structure-performance relationship and explaining the electrochemical reaction mechanism (especially the performance degradation and failure mechanism) of the cathode materials can help to improve the energy density and power density of the materials. Magnetic Resonance techniques, including NMR (nuclear magnetic resonance) and EPR (electron paramagnetic resonance), has been continuously improved during the past three decades of material research, and has gradually become one of the key technologies for studying the structure-performance relationship of cathode materials. NMR could be used to study light elements commonly found in battery materials such as Li, Na, F, P, C, H and O, while EPR can be employed to study transition metals such as Co, Ni, Mn, Fe and V. This paper summarizes the progress of magnetic resonance research on several important commercial cathode materials (LiCoO₂, NCA, NMC and LiFePO₄), and demonstrates the important role of NMR and EPR in the study of structure-performance relationship of cathode materials. It is emphasized here that the development of in-situ technology has gradually shown its importance to investigate the electrochemical reaction mechanism. This article will help to understand the important value of magnetic resonance technology in battery materials research and further promote the development of magnetic resonance technology.