Large-grain graphene thin film current collector and secondary batteries containing same

摘要

A unitary graphene-based current collector in a battery or capacitor. The current collector is or contains a unitary graphene layer that is composed of closely packed and chemically bonded parallel graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content less than 5% by weight (more typically 0.001% to 1%), an average grain size larger than 5 μm (more typically >100 μm; some as large as >cm), a physical density higher than 1.8 g/cm3, and is obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C. (typically and preferably from 1,000 to 3,000° C.). Such an integrated or unitary graphene entity is compatible with essentially all electrolytes commonly used in batteries and supercapacitors.

主权项

1. A unitary graphene layer-based current collector in a battery or capacitor, said current collector being a unitary graphene layer containing closely packed and chemically bonded parallel graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content less than 5% by weight, an average grain size larger than 5 μm, a physical density higher than 1.8 g/cm3, and a tensile strength greater than 40 MPa, and is obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C., wherein said current collector is not an electrode active layer.