Youssry Mohamed, Kamand Fadi Z, Magzoub Musaab I, Nasser Mustafa S
Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University P. O. Box 2713 Doha Qatar
Gas Processing Center, College of Engineering, Qatar University P. O. Box 2713 Doha Qatar.
RSC Adv. 2018 Sep 17;8(56):32119-32131. doi: 10.1039/c8ra05446k. eCollection 2018 Sep 12.
The aqueous dispersions of a special type of carbon black (CB) in 1 M lithium bis(trifluoromethanesulfonimide) electrolyte is mainly controlled by the affinity of the aqueous electrolyte towards the CB particles rather than the particle size. In spite of its small particle size (30 nm), this type of CB forms a three-dimensional open network which is rheologically and electrically percolated at a relatively high threshold (2.0 wt%) with enhanced rheological and electrical properties. At this percolating threshold, replacing a trace amount of CB with equivalent carbon nanofibers (CNFs) produces hybrid dispersions with higher electrical conductivity and comparable rheological behavior to pure CB dispersions. This hybrid dispersion is dominated by a cooperatively supporting network, which is wired by the flexible filamentous nanofibers so that it is able to recover the conductivity loss under flow conditions due to flow-induced breaking up of the conductive pathways of CB and presumably sustain a higher load of active materials. This finding suggests hybrid dispersions as a promising precursor in the formulation of electrode suspensions for aqueous semi-solid redox flow cells.
一种特殊类型的炭黑（CB）在1 M双（三氟甲烷磺酰）亚胺锂电解质中的水分散体主要受水性电解质对CB颗粒的亲和力控制，而非颗粒大小。尽管这种类型的CB粒径较小（30 nm），但它会形成三维开放网络，该网络在相对较高的阈值（2.0 wt%）下发生流变学和电学渗流，且流变学和电学性能增强。在这个渗流阈值下，用等量的碳纳米纤维（CNF）替代痕量的CB会产生具有更高电导率且流变行为与纯CB分散体相当的混合分散体。这种混合分散体由协同支撑网络主导，该网络由柔性丝状纳米纤维连接，因此能够在流动条件下恢复因CB导电路径的流动诱导破碎而导致的电导率损失，并且大概能够承受更高负载的活性材料。这一发现表明混合分散体是用于水性半固态氧化还原液流电池电极悬浮液配方中一种很有前景的前驱体。
