Roll-to-roll printed high voltage supercapattery in lead-contaminated aqueous electrolyte

This work investigated the potential application of roll-to-roll printed PEDOT:PSS on an ITO/PET substrate using Pb²⁺ containing 0.1 M NaCl aqueous solution for a supercapattery. The PEDOT:PSS/ITO/PET electrode achieved 2.2 μAh cm^-2 (46.5 mAh g^-1) in 0.1 M NaCl and 10 μAh cm^-2 (216.8 mAh g^-1) in 2 mM Pb²⁺/0.1 M NaCl at a current density of 0.2 mA cm^-2 (4.34 A g^-1). The electrode also shows good cyclic performance that retains 63% of its initial capacitance after 1000 charge-discharge cycles. A device operating at a high voltage of 1.8 V was built using PEDOT:PSS/ITO/PET in aqueous electrolyte. The energy density of the symmetric PEDOT:PSS/ITO/PET device is 6.2 Wh kg^-1 in 0.1 M NaCl and is improved to 11 Wh kg^-1 in 3 mM Pb²⁺/0.1 M NaCl.