Lithium perrhenate catalyst for carbon aerogel-based supercapacitor

Abstract

Carbon aerogels are unique type of amorphous carbon-based materials with an extraordinary properties including light weight, well-developed and tailored pore structure, high specific surface area, low electrical resistivity and high purity. Therefore carbon aerogels can be used in numerous applications, including energy storage materials such as supercapacitors or lithium-ion batteries. Synthesis of hydrogel requires accurate concentration of monomers and catalysts, exact temperature and time. Low-density carbon aerogel can be produced using a complicated supercritical drying method, which allows to expel solvent without carbon porous structure collapse. Here we report a possibility to use novel type of resorcinol/formaldehyde gelation catalyst based on rhenium salt. The organic gel obtained using lithium perrhenate was traditionally carbonized and examined with respect to energy storage properties. It was found that interaction of lithium and rhenium atoms with monomers resulted in completely different structure than using typical sodium carbonate catalyst.

Hydrometallurgical Method of Producing Lithium Perrhenate from Solutions Obtained during the Processing of Li-Ion Battery Scrap

“…It was found that LiReO 4 is a suitable catalyst for the reaction of resorcinol and formaldehyde gel formation. The gel obtained in the presence of a rhenium catalyst had an increased specific surface area and a better-developed pore structure [28].…”

“…In the seventh oxidation state, it forms stable salts with other metals, such as Ni [20][21][22], Co [20,22], Cs [23], Fe [24], Cu [25], Ag [26,27], as well as with Li, which are called perrhenates. These salts are used in the production of mordants (for the alloys, superalloys, and heavy sinters), in catalysis, and in medicine, although nowadays, these compounds are researched for their use in the battery industry [28,29]. Selected physicochemical properties of the above-mentioned rhenium salts are shown in Table 1.…”