The invention discloses a
lithium ion battery end cover capable of preventing the leakage of an
electrolyte solution and the heating during large-current discharging, a
lithium ion battery and a production method of the
lithium ion battery. The
lithium ion battery end cover is characterized by comprising a cover body, a positive guide pin and a negative guide pin, wherein the
tail parts of the positive guide pin and the negative guide pin are arranged in the cover body and are respectively provided with a guide pin holder for preventing the guide pin from being separated from the cover body, each guide pin holder is a conductor, and the bottom of each guide pin holder is level to the bottom of the cover body. The
lithium ion battery comprises an aluminum shell and a roll core provided with a positive
pole piece and a negative
pole piece in a rolling manner, wherein the end cover with the positive guide pin and the negative guide pin is arranged in an opening of the aluminum shell, and the end cover is connected with the positive
pole piece and the negative pole piece through tabs. The production method comprises the steps of producing the end cover, producing the roll core,
welding, loading the end cover into the shell, rolling, and secondarily
welding. The guide pins are integrally injected into the cover body and are generally seamless; the guide pins are prevented from being withdrawn through the guide pin holders, and the bottom area of the guide pin holders is large, so that the
welding area of the tabs and the pole pieces can be increased, and the tabs and the pole pieces are firm and are unlikely to drop; the contact area is also increased, the impedance is reduced, and the heating during large-current discharging is avoided.