Lithium ion secondary battery and preparation process thereof

• Main Authors: LIANG PENG, LIANG WENBIN, SU ZHIJIANG, WANG WANSHENG
• Format: Patent
• Language: Chinese; English
• Published: 28.06.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention provides a lithium ion secondary battery and a preparation process thereof. The preparation process comprises the following steps: (1) preparing a positive pole piece and a negative pole piece; (2) preparing a pole core; (3) heat sealing and liquid injection; (4) performing formation treatment: performing pre-charging treatment of charging and discharging for one time on the battery cell within the range of the lower limit voltage I and the upper limit voltage I, increasing the upper limit voltage I, and performing charging and discharging for one time within the range of the lower limit voltage I and the increased upper limit voltage I until the upper limit voltage I is increased to the upper limit voltage II; and (5) capacity grading treatment: completing 20-100 times of charging and discharging on the battery after formation treatment within the range of the lower limit voltage II and the upper limit voltage III, increasing the upper limit voltage III, and completing 20-100 times of charging