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Low‐Cost Self‐Assembled Oxide Separator for Rechargeable Batteries
Author(s) -
Grundish Nicholas S.,
Amos Charles D.,
Agrawal Ankit,
Khani Hadi,
Goodenough John B.
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201903550
Subject(s) - separator (oil production) , materials science , electrolyte , chemical engineering , cathode , nanoparticle , polymer , electrode , oxide , wetting , nanotechnology , composite material , chemistry , physics , engineering , metallurgy , thermodynamics
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 SiO 2 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 SiO 2 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 LiCoO 2 cathode coated with SiO 2 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 SiO 2 nanoparticles. The SiO 2 nanoparticles are easy to prepare, cheap, and environmentally friendly.