Exploring the energy storage properties of calcite/carbon composites derived from sargassum: An experimental and theoretical approach
Por:
Kar, T, Celaya, CA, Flores-Rodriguez, MF, Jiménez-Juárez, JA, Castro-Ocampo, O, Muñiz, J, Kesarla, MK
Publicada:
1 ago 2026
Resumen:
High surface area conducting carbon derived from biomass is a promising material for electrochemical energy storage. Herein, we report that the presence of crystalline calcite in carbon derived from Sargassum natans significantly enhances electrochemical capacitance. The materials were characterized by XRD, SEM, and EDS to determine their crystalline structure, morphology, and composition. Electrochemical measurements in 6.0 M KOH revealed that KOH-activated carbon containing abundant calcite exhibits a high specific capacitance of 185.4 F g-1, whereas HCl-washed carbon lacking calcite shows a reduced capacitance of 107 F g-1. A two-electrode device fabricated with calcite-rich carbon delivers an energy density of 13.31 Wh kg-1 at a power density of 150 W kg-1. Density functional theory calculations support these findings, showing partially occupied Ca3d states near the Fermi level that increase the density of states and enhance charge storage. Hybridization between O2p and C2p orbitals further promotes charge accumulation and transport. Importantly, excessive Mg content is detrimental, as Mg-derived states suppress the density of states near the Fermi level, reducing quantum capacitance. Overall, optimal inorganic composition is key to maximizing performance.
Filiaciones:
Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Ave Univ S-N, Col Chamilpa, Cuernavaca 62210, Morelos, Mexico
Univ Nacl Autonoma Mexico, Inst Invest Mat, Circuito Exterior Ciudad Univ S-N,Apartado Postal, Mexico City 04510, Mexico
Univ Nacl Autonoma Mexico, Ctr Nanociencias & Nanotecnol, Km 107 Carretera Tijuana, Ensenada 22800, BC, Mexico
Univ Nacl Autonoma Mexico, Inst Energias Renovables, Priv Xochicalco S-N,Col Ctr, Temixco CP 62580, Morelos, Mexico
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