▎ 摘　　要

NOVELTY - High-power lithium iron phosphate start-stop lithium-ion battery comprises diaphragm, electrolyte, aluminum plastic film, positive ears, negative ears, positive electrode sheet and a negative electrode sheet. The positive electrode sheet material includes 92.93-95.96 wt.% lithium iron phosphate, 0.2-1.2 wt.% graphene, 0.3-0.8 wt.% multi-walled carbon nanotubes, 0.2-0.6 wt.% single-walled carbon nanotubes, resistivity less than 2 ~o m, particle size is 45-55nm, 0.6-1.0 wt.% super conductive carbon black, 1.6-3.0 wt.% conductive carbon black, 1-2 wt.% polyvinylidene fluoride, and 0.1-0.5 wt.% povidone dispersant. USE - High-power lithium iron phosphate start-stop lithium-ion battery. ADVANTAGE - The high-power lithium iron phosphate start-stop lithium-ion battery has good safety performance, low material cost, high discharge platform, high specific energy, low internal resistance, large continuous discharge current, high instantaneous discharge current, and good cycle performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing high-power lithium iron phosphate start-stop lithium-ion battery, which involves: (A) preparing the positive electrode sheet and the negative electrode sheet, and cutting them into predetermined sizes; (B) placing the cut positive sheet and negative sheet on the fully automatic stacking machine; (C) separating the positive and negative plates with a separator; (D) laminating the positive electrode sheet and the negative electrode sheet to form a core; (E) welding the winding core on the positive and negative lugs; (F) flattening the weld nugget and applying insulating glue; (G) placing the core into the punched aluminum plastic film for top side sealing; (H) wrapping the protective film to make the battery core, and then testing the short circuit condition of the battery core; (I) selecting the cell that is not short-circuited as the qualified cell according to the short-circuit condition of the cell; (J) inserting the qualified battery cell sealed on the top side into the fixture and put it into the high vacuum oven; (K) vacuumizing the high vacuum oven until the air pressure is less than -100 KPa (L) baking the cell 2H under the constant temperature and pressure condition of 75-95 degrees C; (M) filling the high vacuum oven with nitrogen to the pressure of -35 45MPa for 5 minutes; (N) vacuumizing, baking, and filling with nitrogen until the moisture content in the cell is less than or equal to 200 PPM; (O) injecting 72-77g electrolyte into the cell, and then vacuum sealing it; (P) placing the battery cell in an environment with a temperature of 40 -50 degrees C for 24-48 hours; (Q) placing it in a pressurized chemical conversion cabinet for chemical conversion, the temperature of the chemical conversion is 40-50 degrees C, and the time is 24 hours; (R) placing the battery cell in an environment with a temperature of 25-35 degrees C to age for 120 hours; (S) screening the voltage internal resistance of the cells; (T) screening battery cells with a charging voltage of 3.2-3.25 V and placing in a room temperature environment for 120 hours; and (U) preparing a finished high-power lithium iron phosphate start-stop lithium-ion battery.