Charge compensation and capacity fading in LiCoO<sub>2</sub> at high voltage investigated by soft x-ray absorption spectroscopy

Charge compensation and capacity fading in LiCoO₂ at high voltage investigated by soft x-ray absorption spectroscopy

Long Xing-Hui^{1, 2, 3}, Wu Yan-Ru^{1, 2, 3}, Zhang Nian^{1, 2}, Yu Peng-Fei^{1, 2, †}, Feng Xue-Fei⁴, Zheng Shun^{1, 2, 3}, Fu Jia-Min^{1, 2, 5}, Liu Xiao-Song^{1, 2, 5}, Liu Na⁶, Wang Meng⁶, Xu Lei-Min⁶, Chen Jin-Ming⁷, Lee Jenn-Min⁷

(color online) (a) Normalized Co L_2,3-edge x-ray absorption spectra, (b) normalized oxygen K-edge x-ray absorption spectra of Li_1−xCoO₂ with respect to the cut-off voltage in the TEY mode, and ((c) and (d)) magnified parts of Co L₃ and O K pre-edge spectra above 4.4 V, respectively, which are convenient for comparison.