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Fabrication of Current Collectors and Binder‐Free Electrodes on Separators Used in Lithium‐Ion Batteries
Author(s) -
Delaporte Nicolas,
Osso Diby B.,
Zaghib Karim,
Bélanger Daniel
Publication year - 2020
Publication title -
batteries and supercaps
Language(s) - English
Resource type - Journals
ISSN - 2566-6223
DOI - 10.1002/batt.201900227
Subject(s) - current collector , electrode , materials science , separator (oil production) , electrochemistry , chemical engineering , gravimetric analysis , lithium ion battery , fabrication , composite material , nanotechnology , battery (electricity) , electrolyte , chemistry , organic chemistry , medicine , power (physics) , physics , alternative medicine , quantum mechanics , pathology , engineering , thermodynamics
We report the fabrication of a composite electrode through the deposition of electrode materials directly onto a separator to avoid the use of a metallic current collector. In addition to being an active electrode material, this method employs only graphene as both a carbon additive and a binder. A major achievement is the elimination of heavy and inactive current collector, harmful solvents, and resistive binder. The deposition of the composite film electrode was applied through the filtrated dispersion of a redox active material and graphene through a separator (Celgard), which is commonly used in battery. The electronic conductivity of LiFePO 4 /Celgard electrodes was ∼10 times higher than that of conventional electrodes spread onto an aluminum current collector. The electrochemical performances of LiFePO 4 /C (LFP) and Li 4 Ti 5 O 12 (LTO) half‐cells fabricated according to this process and a conventional method were compared. A clear improvement in the electrochemical performance for electrodes fabricated using the new method was observed, particularly at high C‐rates. LiFePO 4 /Celgard electrodes deliver specific capacities of up to 125 mAh.g −1 electrode corresponding to more than 6 times the gravimetric capacity of an LFP electrode coated on Al foil. A LiFePO 4 /Li 4 Ti 5 O 12 full cell made using film electrodes deposited on a Celgard membrane shows stable specific capacities during the cycling at various C‐rates and delivers a specific capacity of 106 mAh.g −1 electrode at a C/10 rate.