US Patent 11646424 Lithium-ion secondary battery

This application discloses a lithium-ion secondary battery. The lithium-ion secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and an electrolytic solution. The positive electrode plate includes a positive electrode current collector and a positive active material layer disposed on a surface of the positive electrode current collector and containing a positive active material, and the negative electrode plate includes a negative electrode current collector and a negative active material layer disposed on a surface of the negative electrode current collector and containing a negative active material; wherein the positive active material includes lithium iron phosphate, and the negative active material includes graphite; and wherein the positive electrode current collector and/or the negative electrode current collector is a composite current collector, and the composite current collector includes an organic support layer and a conductive layer disposed on at least one surface of the organic support layer.