The specific operation of determining the internal moisture of the electrode paste is as follows:
(1) Definition The intrinsic moisture of the electrode paste refers to the moisture lost when the air-dried sample is heated to 110℃±5℃.
Air-dried sample: If the mass of the sample does not change more than 0.1% after the electrode paste is continuously dried for 1 hour at a temperature not higher than 50℃, the sample is called an air-dried sample.
(2) Instruments and equipment
- Analytical balance: Sensitivity is 0.1mg.
- Drying box: with automatic temperature control device, equipped with a blower, and can maintain the temperature within the range of 1110 ℃ ± 5 ℃.
- Dryer: built-in discoloration silica gel or granular anhydrous calcium chloride.
- Porcelain dish: 60mL.
(3) Test procedure
- Weigh 1050g sample with pre-dried and weighed porcelain dish, accurate to 0.2mg. Spread the sample flat in a porcelain dish.
- Open the lid of the porcelain dish, put the sample together with the porcelain dish into a drying oven that started blowing 35 minutes in advance and heated to 110 ℃ ± 5 ℃, and dried for 2 hours under constant blast conditions.
- Take out the porcelain dish from the drying box, cover the porcelain dish lid and put it in a desiccator to cool to room temperature (about 30min) and then weigh.
- Carry out inspection drying for 30 minutes each time until the mass of the dried sample does not decrease more than 0.001g or the mass increases for two consecutive times. In the latter case, the previous mass increase shall be used as the basis for calculation.
(4) Calculate the internal moisture of the carbon material based on the test results as follows:
Mad — the intrinsic moisture value of the sample, %;
m — the quality of the test before drying, g;
m1 — mass of the sample after drying, g.
Take the arithmetic average of the two determination results. Repeatability r≤0.06%.