Li-ion batteries: Phase transition
Hou Peiyu1, Chu Geng2, Gao Jian2, Zhang Yantao1, Zhang Lianqi1, †,
       

STEM-HAADF images of surface structure: (a) pristine LiCoO2, (b) LiCoO2charged to 4.2 V, (c) charged to 4.5 V, and (d) discharged to 3.0 V at the [010] zone axis. (e) Phase diagram of LixCoO2(1 ≤x≤ 0.50) nanoparticle. Numerical symbols 0-4 represent the sample points for STEM observation: (0) pristine LiCoO2, (1) charged to 3.9 V, (2) charged to 4.2 V, (3) charged to 4.5 V, and (4) back to 3.0 V.[28]