Electrophoretically Deposited Activated Carbon/Chitosan Electrodes Combined with Perchlorate-Filled Poly(vinylidene fluoride- co -hexafluoropropylene) Membranes as High-voltage Supercapacitor Devices

Activated carbons (ACs) are very attractive in terms of the preparation of electrode materials for supercapacitors (SCs). Their slurries are frequently deposited on the conductive current collectors. However, this approach is time-consuming and often requires multiple steps. To overcome these inconveniences, this work presents that the ACs can be successfully deposited on the stainless steel discs with the electrophoresis deposition (EPD) method using a small content of chitosan (CS) (∼0.7 wt %) as binder. Moreover, the second objective of this work is to check the compatibility of the obtained AC/CS electrodes with the poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP) gel polymer electrolytes (GPEs) filled with three different salts (LiClO 4, NaClO 4, and Mg(ClO 4 ) 2 ) dissolved in propylene carbonate. The use of GPEs enables long-term and safe operation up to 10,000 cycles with a capacitance retention over 55% at an electrochemical stability window of 2.6 V for all investigated cells. Nevertheless, the SC cell containing the NaClO 4 salt reveals the greatest electrochemical performance. It achieves a specific capacitance of 35.1 F g –1 (measured at 2 A g –1 ), capacitance retention of 84.5% after extended charge–discharge cycling, and an energy density of 35.1 W h kg –1 at a power density of 5.2 kW kg –1 . The obtained results indicate that EPD and a low-content CS can be effectively used to prepare AC-based electrodes for SCs equipped with GPEs.