Cucumis melo var agrestis based activated carbon/manganese ammonium phosphate @ carbon hollow sphere in dual redox additives for supercapattery device

Abstract

The electrochemical performance of manganese ammonium phosphate (MnAP) intercalated carbon hollow sphere (CS) at four mass variates has been investigated. The XRD, Raman, SEM, and electrochemical studies reveal that only 50 mg of CS strongly intercalating with MnAP (MnAP@CS2) is observed. The half‐cell test has shown the profound pseudocapacitance for 50 mg intercalated MnAP@CS2 hybrid composite (2545 C g−1 @ 1 A g−1 in KI added 2 M H2SO4) and confirms the imminence of optimal mass concentration of CS with MnAP and the effect of KI redox additive towards enhancing the specific capacity. The supercapattery hybrid device (SBHD) using MnAP@CS2 as the positive electrode and as newly synthesized activated carbon (AC) derived from cucumis melo var agrestis as a negative electrode is examined in pure 3 M H2SO4 and in 0.025 M KI/VOSO4 dual redox additive added 3 M H2SO4. The exquisite complacency requisite on specific capacitance (536 C g−1/149 mAh g−1 @ 1 A g−1 @ 20 A g−1), energy density (80 Wh g−1), and capacity retention (89% for 5000 charge‐discharge cycles) have profusely advocating MnAP@CS2 and AC for SBH device applications.