High-specific capacity and high-cycle life 18650 cylindrical lithium battery and preparation method thereof

The invention relates to a high-specific capacity and high-cycle life 18650 cylindrical lithium battery which comprises a shell; a positive pole piece, a negative pole piece and an electrolyte are arranged in the shell; a ceramic diaphragm is arranged between the positive pole piece and the negative pole piece, the positive end of the shell is a cap, and the negative end is a steel shell. A positive current collector is made of an aluminum foil material with a thickness of 11-12.5 mum, and an NCA positive active material with high nickel content, a CNT conductive agent and an adhesive are arranged on the positive current collector; a negative current collector is made of a copper foil material with a thickness of 5-7 mum, and a SiC negative active material, a Super P conductive agent and an adhesive are arranged on the negative current collector; the ceramic diaphragm has a thickness of 12-15 mum, and an Al2O3 ceramic diaphragm coats a PE base film. The high-specific capacity and high-cycle life 18650 cylindr