Cathode of lithium-ion secondary battery, preparation method and lithium-ion secondary battery

The invention provides a cathode of a lithium-ion secondary battery, which comprises a current collector and a cathode material layer covered on the current collector. The cathode material layer is prepared by adopting magnetron sputtering technology under the sputtering power of 1,000 to 5,000 W. By greatly improving the target sputtering power of magnetron sputtering, the prepared lithium-ion secondary battery has high charge/discharge capacitance and excellent cycle performance, and improves the production efficiency of the material, has simple manufacturing process and operation and good electrochemical performance, and greatly improves the primary charge/discharge efficiency and the discharge capacity compared with the reported silicon-based film cathode material.