The secret of the magic gourd (II): zinc-silicate integrated with gourd leaf-derived biomass carbon for high-performance supercapacitors

Abstract

As a significant role in the human body, zinc ions were used to prepare the electrodes and devices of the supercapacitors with the amorphous carbon obtained from planted gourd leaves by in situ hydrolysis and in situ hydrothermal treatment. Herein, sandwich structure Zn₂SiO₄·H₂O@C@Zn₂SiO₄·H₂O (C@ZnSi and C@ZnSi@ZnSi) prepared by in-situ growth strategy is facilitated by the insertion and removal of OH⁻ adsorption for energy storage. As the conductive core, the internal amorphous C can facilitate the rapid transfer of electrons, thus significantly enhancing the conductivity of the materials. In detail, in the three-electrode system, C@ZnSi@ZnSi exhibited high electrochemical performance (591 F g⁻¹ at 0.5 A g⁻¹ and the capacitance retention of 98.7% after 10,000 cycles). The HSC devices also achieve very excellent electrochemical properties (the areal specific capacitance with 714 mF cm⁻² at 2 mA cm⁻², the energy density with 4.65 Wh m⁻² at the power density of 15.24 W m⁻² and the cycle stability with 75.8% after 10,000 cycles. Additionally, it opens up a new territory for the preparation of supercapacitors, which enhances electrochemical performance while reducing environmental pollution and lowering costs. Due to the high electrochemical performance of the supercapacitors, it may serve as a possible explanation for the superpowers of the Calabash Brothers, especially the Red Boy and Orange Boy.