The choice of coating method and control parameters have an important influence on the performance of lithium-ion batteries, mainly in:
1) Coating and drying temperature control: If the drying temperature is too low during coating, the pole piece cannot be completely dried. If the temperature is too high, it may be because the organic solvent inside the pole piece evaporates too fast, and the surface coating of the pole piece appears tortoise. Phenomenon such as cracking and falling off;
2) Coating surface density: If the coating surface density is too small, the battery capacity may not reach the nominal capacity. If the coating surface density is too large, it is easy to cause waste of ingredients. In severe cases, if the positive electrode capacity is excessive, due to lithium The precipitation of lithium dendrites pierced the battery diaphragm and short-circuited, causing safety hazards;
3) Coating size: If the coating size is too small or too large, the positive electrode inside the battery may not be completely covered by the negative electrode. During the charging process, lithium ions are inserted from the positive electrode and move to the electrolyte that is not completely covered by the negative electrode. In the middle, the actual capacity of the positive electrode cannot be used efficiently. In severe cases, lithium dendrites will be formed inside the battery, which will easily pierce the diaphragm and cause the internal circuit of the battery;
4) Coating thickness: The coating thickness is too thin or too thick will affect the subsequent pole piece rolling process, and can not guarantee the performance consistency of the battery pole piece.

In addition, the pole piece coating is of great significance to the safety of lithium batteries. Do 5S work before coating to ensure that no particles, debris, dust, etc. are mixed into the pole piece during the coating process. If the debris is mixed, it will cause a micro short circuit inside the battery, which may cause the battery to catch fire and explode in severe cases.

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