Modified metal negative electrode, preparation method thereof and lithium metal battery

The invention relates to the technical field of lithium metal batteries, in particular to a modified metal negative electrode, a preparation method thereof and a lithium metal battery. The modified metal negative electrode comprises a lithium metal negative electrode and an in-situ polymer film covering the lithium metal negative electrode, and the in-situ polymer film and the lithium metal negative electrode are fixedly connected through a chemical bond of fluorine and lithium; wherein the molecular structure of the in-situ polymer membrane comprises at least two fluorine atoms, and the hydrogen content in the molecular structure of the in-situ polymer membrane is less than or equal to 10%; the in-situ polymer film which is rich in fluorine and contains little hydrogen in the modified metal negative electrode can improve the bonding strength between the lithium metal negative electrode and the in-situ polymer film, and the in-situ polymer film which is rich in fluorine and contains little hydrogen can improv