When assembling the button battery, the positive electrode material obtained in the experiment was used, polyvinylidene fluoride (PVDF) was used as the binder, acetylene black was used as the conductive agent, lithium sheet was used as the negative electrode of the battery, and N-methylpyrrolidone (NMP) was used for Dissolve PVDF.
The steps of preparation are:
1. Coating film
Method A:
(1) According to the ratio of positive electrode material: PVDF: acetylene black=81:1, the total mass is 0.5g, weigh 0.4g positive electrode material, 0.05gPVDF, 0.05g acetylene black;
(2) After grinding, add an appropriate amount of NMP dropwise, grind and dissolve the above mixture until there are no particles, and it is almost one phase;
(3) Put the slurry into a Forced Air Drying Oven at 70C, and grind it every once in a while until it reaches an appropriate viscosity, then coat the slurry on the aluminum foil on an automatic film coating machine.
Method B:
(1) According to the ratio of positive electrode material: PVDF: acetylene black=81:1, the total mass is 0.5g, weigh 0.4g positive electrode material, 0.05gPVDF, 0.05g acetylene black;
(2) First add PVDF to the 25*25mm weighing bottle, then add 25 drops of NMP, and stir with a stirring bar;
(3) After the PVDF is stirred until it is completely dissolved, then slowly add the positive electrode material and acetylene black in sequence, and at the same time add an appropriate amount of NMP until the above mixture is just completely stirred;
(4) Keep stirring for more than 5 hours, and observe whether the viscosity of the slurry is suitable at this time. If it is too thin, it can be dried in a blast Drying Oven to a suitable viscosity; if it is too thick, some NMP can be added dropwise, and then Stir evenly; after reaching proper viscosity, coat the slurry on aluminum foil on an automatic film coating machine.
2. Put the coated aluminum foil in a Forced Air Drying Oven at 70°C to dry, wrap the pole pieces with dried A4 paper, and punch them into small discs with the pole piece punching machine matched with CR2032 , and at the same time punch down some pure aluminum sheets in the sheet.
3. Select the appropriate pole piece, weigh the quality of the pole piece and pure aluminum piece with an ultra-micro balance, put it into the battery bag , and record the quality outside the battery bag;
4. Vacuum-dry the battery bag with the pole pieces in a vacuum oven at 110°C and ≤-0.1MPa for more than 6 hours;
5. Then put it into the dry bottle while it is hot, and transfer it to the glove box, then press the negative electrode shell->shrapnel->gasket-→lithium sheet->appropriate amount of electrolyte- electrolyte-→positive electrode sheet- >Gasket->Positive electrode shell sequentially assemble the battery;
6. After the assembled battery is packaged and aged for more than 24 hours, the electrochemical performance test is carried out.
