Although free-standing sheets of multiwalled carbon nanotubes (MWCNT) can provide interesting electrochemical and physical properties as electrodes for redox flow batteries, the full potential of this class of materials has not been accessible as of yet. The conventional fabrication methods produce sheets with micro-porous and meso-porous structures, which significantly resist mass transport of the electrolyte during high-current flow-cell operation. Herein, we developed a method to fabricate high performance macro-porous carbon nano-foam free standing sheets (Puffy Fibers, PF), by implementing a freeze-drying step into our low cost and scalable surface-engineered tape-casting (SETC) fabrication method, and we show the improvement in the performance attained as compared with a MWCNT sheet lacking any macro pores (Tape-cast, TC).
View Article and Find Full Text PDFThis paper presents a review of current routes to utilize sulfur and sulfuric acid. Sulfur is a by-product from sour gas and crude oil processing and the precursor of sulfuric acid. As an oversupply is projected for the near-term future, it is prudent to investigate new sulfur applications and market domains that may facilitate a balancing of supply and demand.
View Article and Find Full Text PDFWe developed a poly(vinylidene fluoride)/carbon nanotube (PVDF-MWCNT) filament as a feed for printing of electrically-conductive and corrosion-resistant functional material by fused filament fabrication (FFF). Using an environment-friendly procedure to fabricate PVDF-MWCNT filament, we achieved the best reported electrical conductivity of printable PVDF-MWCNT filament of 28.5 S cm (90 wt% PVDF and 10 wt% CNT).
View Article and Find Full Text PDFA combination of carbon nanotubes (CNT) and graphene in the form of macroscopic hybrid buckypaper (HBP), exhibits a unique set of properties that can be exploited for many emerging applications. Here, we present a simple, inexpensive and scalable approach for the synthesis of highly conductive auxetic graphene/CNT HBP via wet-filtration-zipping and demonstrate the electrical, electrochemical and mechanical performance (tensile, mode I and mode III fracture) of synthesized HBP. An overall increase in electrical conductivity of 247% is observed for HBP (50 wt.
View Article and Find Full Text PDFThe typical lithium-ion-battery positive electrode of "lithium-iron phosphate (LiFePO) on aluminum foil" contains a relatively large amount of inactive materials of 29 wt% (22 wt% aluminum foil + 7 wt% polymeric binder and graphitic conductor) which limits its maximum specific capacity to 120.7 mA h g (71 wt% LiFePO) instead of 170 mA h g (100 wt% LiFePO). We replaced the aluminum current-collector with a multi-walled carbon nanotube (MWCNT) network.
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