Charging and discharging method for high-capacity retention rate lithium ion battery

Abstract

The present invention relates to charging and discharging methods of a lithium ion battery with a high capacity retention rate, which comprise the following steps: (1) when a number of turns is n, the negative and positive electrodes of the lithium ion battery are only charged; after the charging is finished, a third electrode and a fourth electrode are discharged with controlled current, wherein the controlled current is 0.05-10 A; (2) after standing for 1 hour, the fourth electrode is connected in parallel with the negative electrode of the lithium ion battery to perform the discharge with the positive electrode of the lithium ion battery; (3) common charge and discharge between the positive and negative electrodes of the lithium ion battery occur at the (n+1)th and subsequent turns; (4) the common charge and discharge are continued until the next conditional number of turns, and steps (1)-(4) are repeated; and (5) when the number of cycles reaches the specified number of turns, the charging and discharging methods are finished; n is the conditional number of turns, which is selected from the next turn every time the discharge capacity is attenuated by 0.2-1%. The charging and discharging methods can release active lithium according to the self-demand of each battery cell or battery pack, so as to facilitate the capacity retention rate.