N and P Co‐doped Green Waste Derived Hierarchical Porous Carbon as a Supercapacitor Electrode for Energy Storage: Electrolyte Effects
Muhammad Asif Rabbani, Akeem Adeyemi Oladipo, Mehmet Kuşaf
Abstract
Abstract N, P dual‐doped watermelon peel‐derived carbon (NPW) was prepared and found to exhibit a larger specific surface area of 1809 m 2 g −1 and improved hierarchically interconnected pores than N‐doped and P‐doped carbons. The NPW electrode exhibits excellent electrochemical activity in a three‐electrode setup with 1 M H 2 SO 4 , 6 M KOH, and 1 M Na 2 SO 4 electrolytes; with high specific capacitance (498.8, 397.6, and 378.6 F g −1 at 1 A g −1 , respectively) and an average capacitance retention of ∼96.9 % after 10,000 charge‐discharge cycles at 10 A g −1 . The NPW//NPW‐based symmetric cell with 1 M H 2 SO 4 ‐PVA‐electrolyte provided a high energy density of 71.84 Wh kg −1 at 1 A g −1 and a specific capacitance of 263.9 F g −1 . In the neutral electrolyte, NPW showed a wider operating voltage window of up to 2.0 V with no discernible anodic current and delivered 97.11 Wh kg −1 energy density.