ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Composite of activated carbon derived from coconut shell with sulfur as a high-performance cathode for β″-alumina-based sodium solid-state batteries

Denis Octareta Amelia Putri, Yuniawan Hidayat, Younki Lee, Anisa Raditya Nurohmah, Nazarudin, Volkan Degirmenci, and Fitria Rahmawati

Chemistry Department, Faculty of Mathematics and Natural Sciences, Sebelas Maret University, Surakarta, Indonesia

E-mail: fitria@mipa.uns.ac.id

Received: 1 January 2025  Accepted: 3 April 2025

Abstract:

A novel activated carbon/sulfur (AC/S) composite cathode was synthesized from coconut shell charcoal through a thermal treatment method, with a sulfur-to-activated carbon (S/AC) mass ratio of 5:1. The AC/S composite displayed broad diffraction peaks at 2θ = 23.03° and 2θ = 43.45°, indicating an amorphous carbon structure. Morphology analysis revealed a dense, pore-free structure with particle sizes ranging from 50 to 200 nm. Meanwhile, TEM analysis revealed sulfur encapsulation within a carbon matrix, with encapsulated particle sizes ranging from 10 to 20 nm. FTIR analysis confirmed C–S bonding with characteristic vibrations at 1189.17 cm⁻¹, supported by Raman peak at 996.08 cm⁻¹ and XPS signals at 164.03 eV and 165.21 eV. The composite exhibited a high electronic conductivity of 1.11 × 10^ (− 1) S cm⁻¹. Electrochemical performance tests of the AC/S composite as a cathode in an all-solid-state sodium battery (AC/S | PTFE-β”-Al₂O₃ | Na) demonstrated promising initial charge and discharge capacities of 553.01 mAh/g and 331.9 mAh/g, respectively. Cycle stability tests further showed a Coulombic efficiency of 74% and capacity retention of 22.33% over 150 cycles, highlighting the composite’s potential for sustainable, high-capacity sodium storage applications.

Keywords: Batteries; Carbon Materials; Composites; Electrochemistry; Sodium; Supercapacitors; Activated carbon–sulfur composite; Coconut shell; β″-Alumina; Solid-state sodium battery

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04051-2

Chemical Papers 79 (6) 4001–4017 (2025)