Sintering Reaction and Pyrolysis Process Analysis of Al/Ta/PTFE

Abstract

When the Al/Ta/PTFE reactive material was sintered at 360 °C in a vacuum sintering furnace, it was found that the material reacted to form a soft fluffy white substance and carbon black. To explore the reaction process further, powder samples of pure PTFE, Al/PTFE, Ta/PTFE and Al/Ta/PTFE, and molded cylindrical specimens were prepared. A TG-DSC test was carried out on the thermal reaction of four reactive materials, and XRD phase analysis was conducted on the white product, formed by the sintering reaction and the residue of the TG-DSC test sample, based on which of the pyrolysis processes and reaction mechanisms were analyzed. The results show that Ta and PTFE could have a chemical reaction at sintering temperature (360 °C) to form soft and fluffy white material TaF3 and carbon black, which can overflow the surface of the specimen and cause cracking of the specimen, which is tightly pressed. Since no obvious exothermic peak showed up on the TG-DSC curve, the composition of the residue of TG-DSC sample at different temperatures was tested and TaF3 was detected in the residue at 350 °C and 360 °C, indicating that Ta began to react with PTFE at a temperature range of 340–350 °C. According to the chemical properties and product formation of Ta, it could be speculated that the reaction mechanism between Ta and PTFE involves the PTFE decomposing first, then the fluorine-containing gas product reacting with metal Ta. According to the temperature range of the reaction, it is estimated that PTFE starts to decompose before 500 °C, but it is not detected effectively by TG-DSC, and the introduction of Ta could also affect the decomposition process of PTFE.

A Fluorination Method for Improving Cation‐Disordered Rocksalt Cathode Performance

“…PTFE, on the other hand, melts at a much lower temperature of 327 °C and decomposes before 500 °C. [ 33 ] This renders PTFE a more superior fluorination precursor than LiF.…”

An in situ LiF-enriched solid electrolyte interphase from CoF2-decorated N-doped carbon for dendrite-free Li metal anodes

“…Polytetrafluoroethylene (PTFE) is a kind of fluorine-containing material with the highest fluorine content (up to 75%) among all fluoropolymers. 39 When it is thermally decomposed, PTFE can serve as the spatial condition creator by releasing highly oxidizing fluorine-containing radicals. 40 Hence, it is highly desirable to combine the MOF derivation and fluorination strategy to prepare MOF-derived metal fluorides for achieving homogeneous Li deposition of Li metal anodes.…”

Effect of Sintering Factors on Properties of Al-Rich PTFE/Al/TiH2 Active Materials

“…In the last ten years, the main research based on Al/PTFE reaction materials is as follows: (1) study on the composition ratio and mixing methods of Al/PTFE-based active materials; (2) study on the mechanical properties, reaction characteristics, impact sensitivity, ignition mechanism and hot spot formation mechanism of crack tip of Al/PTFE-based active materials; (3) study on the energy release characteristics of Al/PTFE-based active materials; (4) study on the establishment of a theoretical model of impact-induced chemical reaction of Al/PTFE-based active materials. Among them, some scholars introduce high density metals such as Ni [ 13 ], W [ 14 , 15 ] and Ta [ 16 ] into Al/PTFE-based active materials to improve their hardness, density, strength and other characteristics; some scholars have added metal oxides CuO [ 17 ], Fe 2 O 3 [ 18 ] and MnO 2 [ 19 ] to Al/PTFE-based active materials to improve their reaction characteristics; some scholars have added high-energy additives such as TiH 2 [ 20 ] and ZrH 2 [ 21 ] to Al/PTFE-based active materials to improve their energy release characteristics. Based on published literature of the above studies, it can be found that most scholars mainly study the influence of distribution ratio, particle size and other factors on material properties through a given sintering control curve, while few scholars study the influence of sintering control factors on material properties.…”