Enhanced Electrochemical Behavior of Peanut-Shell Activated Carbon/Molybdenum Oxide/Molybdenum Carbide Ternary Composites

Nanomaterials

Ncholu Manyala¹  BridgetK. Mutuma¹  NdeyeF. Sylla¹  Samba Sarr¹  Astou Seck²  Mohamed Chaker²  NdeyeM. Ndiaye³  BallaD. Ngom³ 

[1] Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa;Institut National de la Recherche Scientifique Centre—Énergie Matériaux Télécommunications 1650, Boulevard Lionel Boulet, Varennes, QC J3X 1S2, Canada;Laboratoire de Photonique Quantique, d’Energie et de Nano-Fabrication, Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar (UCAD), Dakar-Fann Dakar B.P. 5005, Senegal;

关键词: porous carbon;    ternary composite;    molybdenum oxide;    molybdenum carbide;    energy storage;   

DOI  :  10.3390/nano11041056

来源: DOAJ

【 摘 要 】

Biomass-waste activated carbon/molybdenum oxide/molybdenum carbide ternary composites are prepared using a facile in-situ pyrolysis process in argon ambient with varying mass ratios of ammonium molybdate tetrahydrate to porous peanut shell activated carbon (PAC). The formation of MoO₂ and Mo₂C nanostructures embedded in the porous carbon framework is confirmed by extensive structural characterization and elemental mapping analysis. The best composite when used as electrodes in a symmetric supercapacitor (PAC/MoO₂/Mo₂C-1//PAC/MoO₂/Mo₂C-1) exhibited a good cell capacitance of 115 F g⁻¹ with an associated high specific energy of 51.8 W h kg⁻¹, as well as a specific power of 0.9 kW kg⁻¹ at a cell voltage of 1.8 V at 1 A g⁻¹. Increasing the specific current to 20 A g⁻¹ still showcased a device capable of delivering up to 30 W h kg⁻¹ specific energy and 18 kW kg⁻¹ of specific power. Additionally, with a great cycling stability, a 99.8% coulombic efficiency and capacitance retention of ~83% were recorded for over 25,000 galvanostatic charge-discharge cycles at 10 A g⁻¹. The voltage holding test after a 160 h floating time resulted in increase of the specific capacitance from 74.7 to 90 F g⁻¹ at 10 A g⁻¹ for this storage device. The remarkable electrochemical performance is based on the synergistic effect of metal oxide/metal carbide (MoO₂/Mo₂C) with the interconnected porous carbon. The PAC/MoO₂/Mo₂C ternary composites highlight promising Mo-based electrode materials suitable for high-performance energy storage. Explicitly, this work also demonstrates a simple and sustainable approach to enhance the electrochemical performance of porous carbon materials.

【 授权许可】

Unknown