Research / 2020 / Article / Fig 4

Research Article

Large-Scale Synthesis of the Stable Co-Free Layered Oxide Cathode by the Synergetic Contribution of Multielement Chemical Substitution for Practical Sodium-Ion Battery

Figure 4

Air-exposure stability and crystal structure evolution under Na+ (de)intercalation. (a) In situ XRD patterns of air-exposure stability test for three days (the different colour regions stand for the different air-exposure stages). (b–d) Galvanostatic charge/discharge curves versus specific capacity at 0.2C and cyclic voltammograms at 0.1 mV s-1 in different cycles as well as cyclic voltammograms at different scan rates after exposing O3-NaNCMMT cathode material to air for three days. (e) In situ XRD patterns during the charge/discharge process at 0.1C in the voltage range of 2.0-4.0 V and corresponding intensity contour maps (bird’s eye view) concerning the evolution of the main characteristic diffraction peaks.