Hang-xin Che , Yu-fei Gao , Jia-hui Yang , Song Hong , Lei-duan Hao , Liang Xu , Sana Taimoor , Alex W. Robertson , Zhen-yu Sun
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引用次数: 0
Abstract
Iron-chromium redox flow batteries (ICRFBs) use abundant and inexpensive chromium and iron as the active substances in the electrolyte and have great potential as a cost-effective and large-scale energy storage system. However, they are still plagued by several issues, such as the low electrochemical activity of Cr3+/Cr2+ and the occurrence of the undesired hydrogen evolution reaction (HER). We report the synthesis of amorphous bismuth (Bi) nanoparticles (NPs) immobilized on N-doped graphite felts (GFs) by a combined self-polymerization and wet-chemistry reduction strategy followed by annealing, which are used as the negative electrodes for ICRFBs. The resulting Bi NPs react with H+ to form intermediates and greatly inhibit the parasitic HER. In addition, the combined effect of Bi and N dopants on the surface of GF dramatically increases the electrochemical activity of Fe2+/Fe3+ and Cr3+/Cr2+, reduces the charge transfer resistance, and increases the mass transfer rate compared to plain GF. At the optimum Bi/N ratio of 2, a high coulombic efficiency of up to 97.7% is maintained even for 25 cycles at different current densities, the energy efficiency reaches 85.8% at 60.0 mA cm−2, exceeding many other reported materials, and the capacity reaches 862.7 mAh L−1 after 100 cycles, which is about 5.3 times that of bare GF.
期刊介绍:
New Carbon Materials is a scholarly journal that publishes original research papers focusing on the physics, chemistry, and technology of organic substances that serve as precursors for creating carbonaceous solids with aromatic or tetrahedral bonding. The scope of materials covered by the journal extends from diamond and graphite to a variety of forms including chars, semicokes, mesophase substances, carbons, carbon fibers, carbynes, fullerenes, and carbon nanotubes. The journal's objective is to showcase the latest research findings and advancements in the areas of formation, structure, properties, behaviors, and technological applications of carbon materials. Additionally, the journal includes papers on the secondary production of new carbon and composite materials, such as carbon-carbon composites, derived from the aforementioned carbons. Research papers on organic substances will be considered for publication only if they have a direct relevance to the resulting carbon materials.