Fig. 4. Electrochemical tests for asymmetric full cells.

a Full cell fabrication: three-electrode CVs of the MXene-knotted CNT (Ti₃C₂/CNT) composite electrode and aligned CNT electrode at 50 mV s⁻¹. b Cyclic voltammograms for the full cell at different scan rates. c Galvanostatic charge–discharge curves for the full cell at different current densities. d Cyclic voltammograms at different temperatures at 20 mV s⁻¹ and e cyclic voltammograms with larger voltage windows at low temperatures for the full cell using MXene-knotted CNT composite electrode with a CNT content of 17% as the negative electrode. f Capacitance retention of full cells with different Ti₃C₂ MXene-based electrodes as a function of temperature.