Fabrication and characterization of metal-organic frameworks-5 based on zinc nitrate hydrate for sodium ion battery electrodes

Abstract

The growing need for renewable energy has led to an increasing demand for batteries, along with their associated technological requirements. Electrochemical storage technology depends on electrode and separator materials. The material selected for the battery electrodes is Metal Organic Frameworks (MOFs). MOFs are new materials consisting of a series of organic compounds and metal ions that form a regular pore crystal structure that can be widely applied, one of which is as a sodium ion electrode. MOFs possess unique properties that make them suitable as electrode materials for batteries, including high porosity, tunable multicomponent pore structures, and high surface areas. The aim of this study is to optimize the synthesis parameters of MOF5. MOF5 was synthesized using solvothermal methods at temperatures between 650-850 °C. Zinc nitrate tetrahydrate and acetic acid were dissolved in DMF (N, N-dimethyl formamide). The remaining precipitate (MOF) was soaked three times in DMF and three times in chloroform for 24 hours for each soaking. MOF5 samples have limited thermal resistance and degrade at high temperatures. The optimum stability of MOF5 is found at 650°C. Changes in the structure and surface morphology of MOF5 at high temperatures can impact the material's performance in battery electrode applications. The properties of MOF5 are relatively stable when used in sodium batteries, thanks to the use of a polyvinylidene fluoride (PVDF) binder and epoxy resin. For optimum binder performance, CV testing was carried out by varying the scan rate of 100 mV/s; 80 mV/s; 50 mV/s; 20 mV/s.