A carbon ink for use in thin, conductive, non peelable, amphiphilic, antioxidant, and large-area current collector coating with enhanced lithium ion battery performance.

ABSTRACT

We reported that a stable carbon ink composed of conductive carbon materials (graphene and super P), binder (sodium carboxymethyl cellulose (CMC)), interface active agent (sodium dodecyl sulfate (SDS)), and metal coupling agent ((3-aminopropyl)triethoxysilane (APTES)) for using in coating conducting layer on cathode/anode current collector for LIBs. Graphene materials are obtained using a low-cost graphite material (KS 6) and processing it via a wet ball-milling to exfoliate single layers into the ink. The ink can be coated on the LIB current collector in a large area by a doctor blade to form a carbon layer of about 1 µm without overflow. Carbon-coated current collectors have amphiphilic properties, not peel off under extreme physical and chemical conditions, and resist oxidation under high temperature (200 °C) processing conditions. In addition, carbon-coated current collector are superior to the batteries using bare metal foil a current collectors in the LIB performance of graphite half-cell, graphite full-cell, LiFePO4 half-cell, and silicon-carbon full-cell. These results show that the carbon-coated metal foil can reduce the interface resistance with the active material and improves the adhesion of the active materials to the current collector, avoiding peeling off during charge/discharge process, thereby improving of LIBs performance. The developed method can produce high-quality, low-cost carbon material inks on a large scale through a simple and inexpensive process, and coat them evenly and finely on current collectors, making it possible to achieve efficient industrial and commercial perspectives for next-generation LIB-based current collectors.