Functional diaphragm, preparation method thereof and lithium ion battery containing functional diaphragm

The invention discloses a functional diaphragm, a preparation method thereof and a lithium ion battery containing the functional diaphragm. In the application, the functional diaphragm comprises a diaphragm layer and a functional layer uniformly covering the diaphragm layer; the functional layer comprises an MXene two-dimensional material layer and a nitrogen-doped carbon layer covering the MXene two-dimensional material layer, and transition metal is loaded on the nitrogen-doped carbon layer. The functional diaphragm provided by the invention is a highly ordered mesopore modified diaphragm, the ordered mesopores are used as a lithium ion sieve, lithium ions flowing from a positive electrode electrolyte to a negative electrode interface are homogenized, the lithium ions are induced to be uniformly embedded into and separated from graphite layers, lithium precipitation and growth of lithium dendrites are effectively relieved, and the service life of the functional diaphragm is prolonged. The safety risks of in