The preparation of electrode sheets mainly includes three processes of mixing materials, coating and drying, and slice weighing.
(1) Mixing: The active material prepared by the experiment is fully ground, acetylene black is used as a conductive agent, PVDF is used as and the mass ratio is 80; 10: 10 The ratio is mixed in an agate material mortar Grind for ~20 minutes, after mixing evenly, add an appropriate amount of N-methylpyrrolidone dropwise as a solvent, and continue grinding for ~10 minutes to form a uniform slurry.
(2) Coating and drying: use an automatic coating drying machine. For the positive electrode material, the current collector adopts A1 foil, and use Vacuum Pump to make the Al foil flat on the automatic coating drying machine, as smooth as possible and reduce wrinkles. The rougher side of the Al foil is the coating working surface. Wipe the Al foil repeatedly with absolute ethanol, pour the prepared slurry with uniform viscosity on the Al foil, adjust the thickness of the automatic scraper to 15 um, and wait for the scraper to wipe the Al foil on the surface. After the slurry is pushed evenly, turn off the automatic coating dryer, close the upper cover of the dryer, set the drying temperature to 60°C, and after drying for 2 hours, turn off the coating dryer, and transfer the A1 foil coated with slurry to In a vacuum oven, set the temperature at 100°C and dry for 24 h.
(3) Weighing slices: Use a manual punching ring punching machine, and use a grinding tool with a diameter of 15.8 mm to cut the dried Al foil coated with slurry into electrode sheets with a diameter of 15.8 mm. For each electrode Slices were weighed and recorded. In order to calculate the charge-discharge specific capacity, it is necessary to accurately calculate the mass of the active material. First weigh the total mass of 10 Al foils with a diameter of 15.8 mm, and obtain the mass of one Al foil with a diameter of 15.8 mm as mo, and weigh the mass of the electrode piece with a balance as m, M= (m-mo) * 80%, M is the quality of the positive electrode active material, wherein 80% is the mass ratio of the active material in the mixed slurry .
