Lithium ion battery having desirable safety performance

A lithium ion battery, comprising:

• a positive electrode, comprising a positive current collector, a positive electrode active material layer containing LiCoO2 and being formed on the positive current collector, and a positive lead coupled to the positive current collector, the positive electrode active material layer being provided with a first recess and the positive lead being soldered in the first recess;
• a negative electrode, comprising a negative current collector, a negative electrode active material layer containing graphite or silicon and being formed on the negative current collector, and a negative lead coupled to the negative current collector, the negative electrode active material layer being provided with a second recess and the negative lead being soldered in the second recess;
• a separator disposed between the positive electrode and the negative electrode;
• and
• an electrolyte,
• wherein:
• upper and lower surfaces of the positive lead each is provided with a first insulating glue layer, a surface of the positive electrode active material layer is pasted with a second insulating glue layer corresponding to the second recess,
• the second insulating glue layer has a width larger than a width of the second recess, and
• the second insulating glue layer has a length larger than a length of the second recess.