Atomic Layer Deposition of Al-W-Fluoride on LiCoO₂ Cathodes: Comparison of Particle- and Electrode-Level Coatings.

ABSTRACT: Atomic layer deposition (ALD) of the well-known Al₂O₃ on a LiCoO₂ system is compared with that of a newly developed AlW _x F _y material. ALD coatings (?1 nm thick) of both materials are shown to be effective in improving cycle life through mitigation of surface-induced capacity losses. However, the behaviors of Al₂O₃ and AlW _x F _y are shown to be significantly different when coated directly on cathode particles versus deposition on a composite electrode composed of active materials, carbons, and binders. Electrochemical impedance spectroscopy, galvanostatic intermittent titration techniques, and four-point measurements suggest that electron transport is more limited in LiCoO₂ particles coated with Al₂O₃ compared with that in particles coated with AlW _x F _y . The results show that proper design/choice of coating materials (e.g., AlW _x F _y ) can improve capacity retention without sacrificing electron transport and suggest new avenues for engineering electrode-electrolyte interfaces to enable high-voltage operation of lithium-ion batteries.

SUBMITTER: Park JS 

PROVIDER: S-EPMC6641266 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature