Fig. 5: Comprehensive stability and practical battery performance.
From: Electronegativity and entropy design of layered oxides for sodium-ion batteries
a XRD patterns of O3-Na0.67 electrode. b XRD patterns and c cycling performances of fresh and aged O3-Na0.67. d DSC profile and thermogravimetric analysis–mass spectrometry (TGA–MS) of O3-Na0.67 electrode. The shaded area under the exothermic peak corresponds to the integrated enthalpy change of 208.2 J g−1. The inset shows the corresponding TGA curves, where the residual mass is plotted as a function of temperature. e Schematic illustrations of the electrochemical ion-exchange method. f Cycling performance of the O3-Na0.67 positive electrode in a K half-cell. The inset shows the galvanostatic charge-discharge profiles for the first cycle in the range of 1.5 − 3.9 V at 86.5 mA g−1. g Initial charge/discharge curves of the full cell of O3-Na0.67 positive electrode and hard carbon negative electrode in the range of 1.0 − 4.0 V at 17.3 mA g−1. h Cycling performance with Coulombic efficiency of the full-cell at 86.5 mA g−1, and i schematic drawing of the full-cell configuration.
