Low‐Cost Self‐Assembled Oxide Separator for Rechargeable Batteries. (26th June 2019)

• Record Type: Journal Article
• Authors: Grundish, Nicholas S.; Amos, Charles D.; Agrawal, Ankit; Khani, Hadi; Goodenough, John B.
• Is Part Of: Advanced functional materials. Volume 29:Number 35(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-26
• Subjects: nanoparticles -- rechargeable batteries -- self‐assembly -- separators -- surface functionalization; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201903550
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Rechargeable battery cells having a liquid electrolyte require a separator permeable to the electrolyte between the two electrodes. Because the electrodes change their volume during charge and discharge, the porous separators are flexible polymers with an electronic energy gap E g large enough for the Fermi levels of the two electrodes to be within it. In this work, a porous film of self‐assembled SiO2 nanoparticles is developed as the separator for a Li‐ion battery with a liquid electrolyte. This coating does not require the plasticity of a polymer membrane and has the required large E g . If adsorbed water is removed from the SiO2 surface, the nanoparticles bond to one another and to an oxide cathode to form a plastic self‐assembling porous layer into which the liquid electrolyte can penetrate. The Li‐ion batteries with a LiCoO2 cathode coated with SiO2 as a separator show similar performance to cells with a traditional polypropylene separator and improved cyclability with a reduced volume of liquid electrolyte owing to the electrolyte wetting properties of the SiO2 nanoparticles. The SiO2 nanoparticles are easy to prepare, cheap, and environmentally friendly. Abstract : A porous film of SiO2 nanoparticles has an E g large enough for the Fermi levels of the two electrodes of a rechargeable Li‐ion battery to be within it. The SiO2 particles bond to one another and to an oxide cathode to form a plastic self‐assembling porous layer that can serve as a separator for a rechargeable battery.