*2.4. Fabrication of the Self-Healing Solid-State Supercapacitor*

The supercapacitor device was a symmetric configuration, which was assembled by two pieces of TOCNF-CNT@PANI/PVA-2 (5.0 <sup>×</sup> 1.5 <sup>×</sup> 0.1 cm3) and one piece of TOCNF/PVA (5.0 <sup>×</sup> 1.5 <sup>×</sup> 0.1 cm3). They were immersed into 6 M KOH solution for 12 h before assembling. In symmetrical supercapacitors, the electrolyte and separator were TOCNF/PVA hydrogels, which were sandwiched in TOCNF-CNT@PANI/PVA-2 hydrogels using as electrodes and current collectors. The interfaces between electrodes and separators could be completely glued into a single thin separating layer as excellent self-healing character, thereby manufacturing an integrated solid-state supercapacitor. The electrochemical measurements of supercapacitors were performed on an electrochemical workstation (CHI 760E, Shanghai, China).
