中国物理B ›› 2020, Vol. 29 ›› Issue (2): 26103-026103.doi: 10.1088/1674-1056/ab6585
• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇 下一篇
Zhi-Sen Jiang(蒋之森), Shao-Feng Li(李少锋), Zheng-Rui Xu(许正瑞), Dennis Nordlund, Hendrik Ohldag, Piero Pianetta, Jun-Sik Lee, Feng Lin(林锋), Yi-Jin Liu(刘宜晋)
Zhi-Sen Jiang(蒋之森)1, Shao-Feng Li(李少锋)2, Zheng-Rui Xu(许正瑞)3, Dennis Nordlund2, Hendrik Ohldag2, Piero Pianetta2, Jun-Sik Lee2, Feng Lin(林锋)3, Yi-Jin Liu(刘宜晋)2
摘要: The hierarchical structure of the composite cathodes brings in significant chemical complexity related to the interfaces, such as cathode electrolyte interphase. These interfaces account for only a small fraction of the volume and mass, they could, however, have profound impacts on the cell-level electrochemistry. As the investigation of these interfaces becomes a crucial topic in the battery research, there is a need to properly study the surface chemistry, particularly to eliminate the biased, incomplete characterization provided by techniques that assume the homogeneous surface chemistry. Herein, we utilize nano-resolution spatially-resolved x-ray spectroscopic tools to probe the heterogeneity of the surface chemistry on LiNi0.8Mn0.1Co0.1O2 layered cathode secondary particles. Informed by the nano-resolution mapping of the Ni valance state, which serves as a measurement of the local surface chemistry, we construct a conceptual model to elucidate the electrochemical consequence of the inhomogeneous local impedance over the particle surface. Going beyond the implication in battery science, our work highlights a balance between the high-resolution probing the local chemistry and the statistical representativeness, which is particularly vital in the study of the highly complex material systems.
中图分类号: (X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.)