Bitter Apple Pulp-Derived Porous Carbon with Rich Oxygen Functionalities for High-Performance Zinc-Ion Storage

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Aqueous zinc-ion hybrid supercapacitors (ZIHSCs) require advanced carbon-based cathodes for improved energy and power performance.
• Plant-based biomass offers a sustainable and cost-effective source for developing porous carbon materials with desirable properties.

Purpose of the Study:

• To investigate the potential of bitter apple pulp (BAP) as a precursor for activated carbon synthesis.
• To evaluate the electrochemical performance of BAP-derived activated carbon as a cathode material in ZIHSCs.

Main Methods:

• Bitter apple pulp was activated using KOH at 900 °C to produce porous carbon (BAPC1-900).
• The structural and chemical properties of the activated carbon were characterized using BET surface area analysis and Raman spectroscopy.
• Electrochemical performance was assessed in an aqueous ZnSO4 electrolyte, evaluating energy density, power density, and cycling stability.

Main Results:

• KOH activation significantly enhanced the specific surface area (SSA) to 3254 m² g⁻¹ and pore volume to 1.8 cm³ g⁻¹, compared to the non-activated material.
• The optimized BAPC1-900 cathode delivered a high Zn-ion energy density of 162 Wh kg⁻¹ within a 0-1.8 V potential window.
• The electrode exhibited excellent long-term stability, retaining over 95% capacity after 50,000 cycles.

Conclusions:

• Bitter apple pulp is a viable and sustainable precursor for high-performance activated carbon in ZIHSCs.
• KOH activation is an effective strategy to engineer porous carbon structures with rich oxygen functionalities for enhanced zinc-ion storage.
• The developed material shows significant promise for next-generation aqueous energy storage devices.