The invention discloses a cylindrical
lithium ion battery and a
processing method thereof, which can solve the technical problems that because space inside an existing
lithium battery is reduced, battery
liquid injection is difficult and a certain
safety risk exists. The cylindrical
lithium ion battery comprises a roll core, a shell and current collecting discs, wherein the height of the roll coreis smaller than that of the shell; the shell is cylindrical; the roll core is located inside the shell; tabs are arranged at the two ends of the roll core; one end of the roll core is provided with the positive tab, and the other end of the roll core is provided with the negative tab; the end surfaces of the tabs of the roll core are annular step surfaces; annular grooves are formed in the current collecting discs of positive and negative electrodes; the grooves are
welding areas; the annular step surfaces on the tabs are welded with the annular grooves in the current collecting discs in a fitted manner; and a set spacing is reserved between the head and the
tail of a
welding track during
welding. Compared with the prior art, the cylindrical
lithium ion battery has the advantages that theshort circuit rate can be effectively reduced; the length of each tab is reduced, so that the weight of the battery is reduced and the
liquid injection space of
electrolyte is expanded; and by adopting an annular welding mode, the welding efficiency is improved compared with other multi-track welding
modes.