The development of high output capacitors for EVs and current collectors for batteries
"TOYAL-CARBO®" is composite material for electrodes that has carbon particles attached to the surface of the aluminium foil without any binders. It is produced by applying Toyo Aluminium's unique technologies for creating whiskers. Through the development of this material, we are aiming to extend our business into the field of electrode materials, where high capacitance and low resistance are required.
Aluminium has conventionally been used on electrode current collectors for lithium ion secondary batteries and capacitors due to its corrosion resistance, electrical conductivity, workability, light weight, and low cost. In particular, there are expectations for the selection of this high capacitance and low resistance electrode material in order to realize capacitors and secondary lithium ion batteries for EVs and HEVs, where high outputs are required.
When aluminium foil is used as the current collector on electrodes for batteries and capacitors, an oxide film is essential to improve the corrosion resistance of the electrode plates. However, oxide films have the disadvantage that they block the flow of electric currents. In order to improve electrical conductivity, it is general practice to attach carbon to the electrode plates using binders (a type of adhesive). However, these binders not only increase the resistance of the electrode plates, they can also cause problems if they are used in high temperature ranges.
TOYAL-CARBO® uses whiskers instead of binders to bond carbon to the aluminium foil, so low resistance is achieved in all environments.
The whiskers generated on the surface of the aluminium foil measure about 20 to 30 nm in diameter and are composed of aluminium carbide (Al4C3). These nanoscale whiskers serve as binders to bond carbon to the surface of the aluminium foil.
- ・Electrodes and current collectors for capacitors and secondary lithium-ion batteries for EVs and HEVs
- ・Electrodes for functional solid polymer capacitors
- ・Electrodes for aluminium electrolytic capacitors