A lithium ion chemical battery includes a casing made of a sealing material, an electrolyte solution in the casing, a positive electrode and a negative electrode which are partially immersed in the solution. The casing adopts halogen-containing plastics as preparing materials and comprises an upper cover, a lower cover and a casing body. The casing body is a hollow cuboid or cylinder. The upper cover and the lower cover are respectively adhered to the upper and lower end faces of the casing body by using polyviny chloride glue, and are characterized in that the polyviny chloride gule prescription comprises substances such as polyviny chloride or modified polyviny chloride plastics, tetrahydrofuran and so on.