Experimental and molecular simulating study on promoting electrolyte-immersed mechanical properties of cellulose/lignin separator for lithium-ion battery. (October 2020)

• Record Type: Journal Article
• Authors: Xie, Weigui; Dang, Yanping; Wu, Lin; Liu, Wangyu; Tang, Aimin; Luo, Yuanqiang
• Is Part Of: Polymer testing. Volume 90(2020)
• Publication Date: 2020-10
• Subjects: Cellulose/lignin composite separator -- Electrolyte immersion -- Mechanical properties -- Molecular simulation; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2020.106773
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: Lithium-ion batteries have been developing intensively and earn an unprecedented reputation, yet advanced performance and safety issue still require considerable investigation. Separator is vital to comprehensive properties of batteries, where the mechanical properties are key to breaking through of new-type separator. Unfortunately, electrolyte submersion has caused damage to strength of cellulose separator. Whereupon, in this work, cellulose separator is optimized by introducing lignin particles to promote electrolyte-immersed mechanical strength. Experiments are conducted concerning surface morphology, contact angle, porosity, electrolyte uptake, mechanical properties and electrochemical performance. Molecular simulation is implemented to explore the mechanism of tensile behavior of cellulose and lignin subjected to electrolyte solvents. Experimental results confirm positive effect of lignin addition in improving mechanical properties and simultaneously maintaining impressive electrochemical performance of the cellulose/lignin composites separators. Besides, lignin addition amount of 2.5% and 5% is recommended to achieve promising overall properties. Molecular simulation has successfully unveiled that weakening of cellulose separator submerged in electrolyte is resulted by the deformed cellulose amorphous region and the promoting effect of adding lignin is contributed from the new hydrogen bonds generated between cellulose and lignin molecules. Hopefully, this work provides novel insight on preparing remarkable separator and mechanism of materials behavior. Graphical abstract: Cellulose/lignin composite separator is prepared, whose mechanical properties in electrolyte immersion are improved and validated through experimental and molecular simulating study. Image 1 Highlights: Lignin is utilized and verified to improve electrolyte immersed mechanical properties of cellulose separator. Introduction of lignin causes no harm to electrochemical performance of cellulose/lignin separators. Addition amount of 2.5% and 5% lignin is suggested for superior comprehensive properties. Molecular simulation is conducted and successfully unveils mechanism of cellulose and lignin's tensile behavior.