Center and multi-points current collecting for improving capacitances of rectangular polypyrrole/knitted cotton fabric-based supercapacitor

Polypyrrole (PPy) electrodes with favorable pseudocapacitance are rapidly developed for supercapacitor. However, longer PPy electrodes are usually underutilized, which affects their capacitances. Herein, rectangular textile-based electrodes, PPy/knitted cotton fabric (PKCF), is fabricated via in-situ polymerization, and the effects of electrodes length on their capacitances are investigated. To improve capacitances of longer PKCF, a center current collecting method is proposed, which enhances 46.8% capacitance for the PKCF at 20 mA. Besides, the capacitance of PKCF is further improved from 5190 to 6950 mF (at 4 mA) via a means of multi-points current collecting. According to the results, a reduced potential decrease mechanism is put forward to explain the enhanced capacitances. The obvious differences of device capacitances (1985-100 mF, 3440-2125 mF and 3750-2900 mF at 4-20 mA, based on end, center and multi-points current collecting, respectively) indicate the proposed latter two methods are effective to make more utilization of PKCF, which is instructive for the practical application of longer electrodes and corresponding devices.

Automated summary

Polyprrole (PPy) electrodes with favorable pseudocapacitance have been rapidly developed for supercapacitors. However, longer PPy electrodes are often underutilized, affecting their capacitances. A study investigated the effects of electrode length on capacitances and proposed methods to improve capacitance for longer electrodes, such as center current collecting and multi-points current collecting. The research demonstrated significant improvement in capacitances for longer PKCF electrodes through these methods, providing insights for practical applications of longer electrodes and devices.