Related Experiment Video
Updated: Dec 15, 2025

Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries Using Synchrotron Radiation Techniques
Published on: November 11, 2013
Excess-Li Localization Triggers Chemical Irreversibility in Li- and Mn-Rich Layered Oxides
Jaeseong Hwang1, Seungjun Myeong1, Wooyoung Jin1
1Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, 44919, Republic of Korea.
Abstract:
Li- and Mn-rich layered oxides (LMRs) have emerged as practically feasible cathode materials for high-energy-density Li-ion batteries due to their extra anionic redox behavior and market competitiveness. However, sluggish kinetics regions (<3.5 V vs Li/Li+ ) associated with anionic redox chemistry engender LMRs with chemical irreversibility (first-cycle irreversibility, poor rate properties, voltage fading), which limits their practical use. Herein, the structural origin of this chemical irreversibility is revealed through a comparative study involving Li1.15 Mn0.51 Co0.17 Ni0.17 O2 with relatively localized and delocalized excess-Li in its lattice system. Operando fine-interval X-ray absorption spectroscopy is used to simultaneously observe the interplay between transition-metal-oxygen (TM-O) redox chemistry and TM migration behavior in real time. Density functional theory calculations show that excess-Li localization in the LMR structure attenuates TM-O covalency and stability, leading to overall chemical irreversibility. Hence, the delocalized excess-Li system is proposed as an alternative design for practically feasible LMR cathodes with restrained TM migration and sustainable O-redox chemistry.
More Related Videos
Related Concept Videos
Ionic Bonding and Electron Transfer
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Common Ion Effect
Alkali Metals
Table 1: Properties of the alkali metals
Weak Acid Solutions
Complexation Equilibria: The Chelate Effect

