Protective tool

The utility model discloses a protection tool, which comprises a first protection piece, a second protection piece and a third protection piece, the first protection piece is an insulating piece, and a protection cavity with an opening in one side is defined on the inner side of the first protection piece; and the second protection part is a high-temperature-resistant part, and the second protection part is connected with the first protection part and covers the outer side of the first protection part. According to the protection tool disclosed by the utility model, by arranging the first protection piece and the second protection piece, the pole can be accommodated in the protection cavity, so that when the sealing nail and the top cover of the battery monomer are welded and sealed, the protection tool can block a welding medium which is shot to the pole; therefore, the risk of pole damage caused by contact between the sputtered welding medium and the pole can be effectively reduced, and the quality and reliability of the battery monomer can be improved to a certain extent.