Composite pole piece, preparation method thereof and lithium ion battery

The invention provides a composite pole piece, a preparation method thereof and a lithium ion battery. The composite pole piece comprises a negative current collector, a negative active material layer and a functional coating which are sequentially stacked, the functional coating comprises phenolic resin and solid electrolyte. The phenolic resin and the solid electrolyte are used as main substances of the functional coating, on one hand, the impedance of the pole piece is effectively reduced, the electrical performance of the battery is improved, on the other hand, on the basis of not influencing the conductivity of lithium ions, the mechanical strength of the pole piece is improved, and the safety performance of a traditional liquid battery is effectively improved; and the lithium ion battery with high energy density can smoothly pass safety tests such as needling, hot box and extrusion. 本发明提供一种复合极片及其制备方法和锂离子电池，所述复合极片包括依次层叠设置的负极集流体、负极活性物质层和功能性涂层；所述功能性涂层包括酚醛树脂和固态电解质。本发明通过使用酚醛树脂和固态电解质作为功能涂层的主要物质，一方面有效降低了极片的阻抗，