Carbon Coated Aluminum Foil Roll as Battery Cathode Current Collector, CBCCCCAFR

Carbon-coated aluminum foil is a high-performance evolution of the standard cathode current collector. It consists of a high-purity aluminum foil (typically 12 um to 25 um thick) that is coated on one or both sides with a sub-micron layer (0.5 um to 2 um) of conductive carbon—typically a mix of carbon black, graphite, or graphene. The carbon coating acts as a "functional bridge" between the metal current collector and the active cathode material. Its multifunctional roles are highlighted below:

(1) Drastic Reduction in Contact Resistance: Metal-to-particle contact is often poor. Carbon-coated foil creates an interface where the conductive carbon fills the microscopic valleys of the aluminum, ensuring a continuous electrical path. This can reduce internal resistance by up to 40%.

(2) Enhanced Adhesion (Peel Strength): The carbon layer provides a rougher, high-surface-area substrate that bonds much more strongly with the anode slurry binders. This prevents "delamination" (peeling) during high-speed manufacturing or long-term cycling.

(3) Corrosion Protection: The carbon layer acts as a chemical barrier. It protects the aluminum from being oxidized by the moisture in the air or being corroded by the acidic byproducts (like HF acid) that can form in the electrolyte over time.

References:

1. I. Doberdò, et al.,Enabling aqueous binders for lithium battery cathodes – Carbon coating of aluminum current collector, J. Power Sources, 2014, 248, 1000-1006. 
2. T. Li, et al., Carbon-coated Aluminum Foil as Current Collector for Improving the Performance of Lithium Sulfur Batteries, I. J. Electrochem., Soc., 2017, 12, 3099-3108.