A Rapid Formation Method for Polymer Lithium Ion Battery

    A rapid formation method of polymer lithium ion battery, the method is to form and charge the battery by keeping constant temperature, changing voltage and increasing current. After charging, battery can be pumped and sealed and and its capacity can be sorted.

The advantage of the invention, firstly, it can furthest decrease the polarization phenomenon during formation, effectively improve the current density inside in the battery The reasonable match of the temperature and pressure avoids the phenomenon polarization and bulge. The generated SEI film (solid electrolyte interface film) will be more dense,which will improve the electrical and safety performance. Secondly, it can make the traditional cooperation procedure rest-preforming-rest-electrification unify into one integrated formation equipment, greatly shorten the time of formation and obviously improve production efficiency.

    The steps of the rapid formation method of polymer lithium ion battery includes below 4 steps:

Step 1. Bake the cell at high vacuum temperature to remove moisture, inject the electrolyte and seal;

Step 2. After injection and seal, put the battery into unified formation equipment of variable pressure control system, temperature control system, time control system. No need rest. Set temperature at 55℃, form and charge the battery by keeping constant temperature, changing voltage and increasing current;

Step 3. Set current, pressure and time into four stage respectively(1) Gradually increase current, the current in four stages A1, A2, A3 and A4 is respectively 0.1c, 0.2C and 0.5C 1C respectively; (2) The pressure in the four stages is respectively T1, T2, T3, and T4, 0.1mpa, 0.2mpa, 0.3mpa, 0.1mpa (T1-T3 gradually increases, while T4 decreases). (3) The four stages are set as time H1, H2, H3, and H4 respectively, 10min, 15min, 20min, 25min

Step 4. The battery shall be formed and charged per the temperature of Step 2 and per the current, pressure, time of Step 3. After charging, After charging, pump, seal and sort the battery.