Fig. 6.

a Photograph of an as-fabricated self-charging power system, including three EP-TENGs in parallel and three EP-SCs in series (scale bar, 1 cm). Reprinted with permission from Ref. [24]. b Schematic structure of a kirigami-based supercapacitor (KP-SC). Reprinted with permission from Ref. [26]. c Fabrication of the convoluted power device. Reprinted with permission from Ref. [27]. d Structural scheme of the PC-SCPU. Insets 1 and 2 show the basic working component of the P-TENG and P-SC. Insets 3 and 4 are the SEM image of the graphite-based electrode (scale bar, 2 μm) for the P-SC and the nanostructured FEP film (scale bar, 2 μm) for the P-TENG. Inset 5 shows a photograph of the as-prepared P-SCPU, which is compared with a coin (scale bar, 3 cm). Reprinted with permission from Ref. [28]