Hydrofluoric Acid Modified Porous Magnesia Fibers as Immobilizing Agent for Molten Electrolyte in Thermal Battery

Abstract

In this work porous MgO fibers were prepared by a hydrothermal method and modified by the reaction with different amounts of hydrofluoric acid solution. Their composition, morphology and porosity were characterized. Separators for thermal batteries were prepared by mixing of definite amounts of dry electrolyte powder (LiCl:KCl = 45:55 wt%) with MgO powder, pristine porous MgO fiber or hydrofluoric acid modified porous MgO fiber. The electrolyte leakage of the separator using the modified porous fibers as the immobilizing agent is lower than that of the separator using MgO powder or pristine fiber as the immobilizing agent. Moreover, the model cells using the modified porous MgO fiber as the immobilizing agent show longer discharge time and larger specific capacity compared with the model cells using MgO powder or pristine fiber as the immobilizing agent. It can be concluded that porous magnesia fibers modified by hydrofluoric acid are a promising immobilizing agent for electrolyte in thermal batteries.

Electrospun Wrinkled Porous Polyimide Nanofiber-Based Filter via Thermally Induced Phase Separation for Efficient High-Temperature PMs Capture

“…Figure b exhibits the differences of wrinkled porous PI nanofiber mat and few porous fiber materials by diverse methods on BET specific surface area (seen in Table S2). It stated clearly that the specific surface area of the wrinkled porous PI fiber mat prepared in this paper was far higher than that of the porous polymer fibers prepared in most ways, ,− including acid etching, − solvent vapor annealing, salt-induced, and nonsolvent phase separation, , except the carbon fibers , obtained by superhigh temperature carbonization, which indicates its potential application in the field of filtration. Figure c presents the PM2.5 filtration performance comparison of current filtration materials and as-prepared wrinkled porous PI filter under high airflow speed (Table S3).…”

Ion Transport in MgO Porous Fibers Retained Molten Salt Electrolytes for Thermal Batteries

“…With the different reaction time, the amounts of HF solution are 20 mol%, 40 mol% and 60 mol% of the MgO fibers respectively. 18 The obtained white products were washed using ultrapure water for several times and dried at 80 • C, then calcined at 500 • C for 8 h. Finally, the HF modified MgO fibers were obtained and marked as MgO-20HF, MgO-40HF and MgO-60HF.…”

“…The results reveal that the HF modified MgO porous fibers have prominent immobilizing ability to molten electrolyte. According to LU, 18 this is mainly attributed to the large specific surface of the modified MgO porous fibers. In addition, the formed MgF 2 improves the absorption of molten electrolyte onto MgO porous fibers, because of its irregular morphology.…”