High electrochemical stability of polyvinylidene fluoride (PVDF) porous membranes using phase inversion methods for lithium-ion batteries

Autor: Zaniar Tabani, Hafez Maghsoudi, Abolfazl Fathollahi Zonouz
Rok vydání: 2020
Předmět:
Zdroj: Journal of Solid State Electrochemistry. 25:651-657
ISSN: 1433-0768
1432-8488
Popis: Polyvinylidene fluoride (PVDF) porous membranes were prepared by non-solvent-induced phase separation (NIPS) method. The membranes were made by different compositions of binary N-methyl-2-pyrrolidone/acetone mixture as the solvent. Ethanol and deionized water were utilized as the non-solvent. The effect of the composition of the two solvents on the structural, mechanical, and electrochemical properties of the membranes was investigated in the lithium-ion batteries (LIBs). Results show that by increasing the N-methyl-2-pyrrolidone (NMP) content of the solvent, the electrolyte uptake of the membrane is increased. Furthermore, using ethanol as non-solvent results in more uniform membranes with higher porosity. All of the synthesized samples demonstrate better results, as compared to the Celgard 2400, except for the tensile strength. Specifically, a membrane with good physical and electrochemical properties is achieved when the ratio of NMP/acetone is 40:60 (by weight). That sample is selected as the optimal membrane. Thermal shrinkage of optimal sample at 160 °C is 37.5% while that is 90.7% for Celgard 2400. Its ionic conductivity and electrochemical stability are 1.2 mS/cm and up to 5 V, respectively. The initial capacity of the optimal sample (NMP/acetone of 40:60) is 141 mAh/g while the reported value for Celgard 2400 is 126 mAh/g. These results indicate that PVDF porous membranes prepared by the proposed NIPS method show good electrochemical stability and cycling performance for the application of LIBs.
Databáze: OpenAIRE
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