Lithium battery pole piece/diaphragm coating equipment and process

Abstract

The invention discloses lithium battery pole piece / diaphragm coating equipment which comprises a coating machine body and a tail gas treatment mechanism, the coating machine body is provided with a closed high-pressure-resistant cavity, and an unwinding mechanism, a coating mechanism and a winding mechanism are sequentially arranged in the cavity. A heating device for heating a coating in a radiation mode is arranged between the coating mechanism and the winding mechanism, the tail gas treatment mechanism comprises a first-stage condenser, a second-stage condenser, a gas-liquid separator, a vacuum buffer tank and a vacuum pump which are sequentially connected through vacuum pipes, and the gas-liquid separator is connected with a recovered solvent storage tank through a liquid separation pipe; a tail gas extraction opening communicated with the cavity is formed in the coating machine body and is connected with the first-stage condenser through a vacuum pipe; the invention also discloses a lithium battery pole piece / diaphragm coating process. The process comprises the following steps of S1, nitrogen charging, S2, coating, and S3, tail gas treatment; and energy consumption can be reduced, enterprise cost can be reduced, and solvent recovery rate and product quality can be improved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a lithium battery pole piece / diaphragm coating equipment and process. Background technique [0002] Usually, when manufacturing a lithium battery, it is necessary to coat a layer of polymer on the positive electrode and negative electrode materials of the battery. It is separated from the positive and negative plates. The current drying principle of the coating machine is to use the convection heat transfer method to dry the solvent on the surface of the pole piece or the membrane with the flowing air after heating. The existing scheme is to dry under normal pressure. If it is carried out at a higher temperature (usually 100-130°C), the coating on the surface of the pole piece or diaphragm may be deformed or cracked due to the rapid temperature rise. The dried exhaust gas containing solvent usually needs cooling recovery or adsorption treatment. In the exhaust ga...

AI Technical Summary

Problems solved by technology

This convection drying method uses a lot of energy to heat the air and cool the exhaust gas, which has the characteristics of high energy consumption and difficult treatment of exhaust gas

The existing technology needs to heat and cool a large amount of air, so the equipment for heating and exchanging heat for the air is bulky, there are many air ducts, and the investment cost is high

And there is water vapor in the air, the existing method also makes the moisture content in the solvent recovered by condensation higher, so that the energy consumption of the subsequent solvent purification process is also higher, and the water vapor in the air will interact with the positive electrode active material (such as ternary materials, lithium iron phosphate, lithium cobalt oxide, etc.) to reduce the capacity of the battery

Existing solutions also allow the oxygen in the air to oxidize the surface of the battery pole piece at a higher temperature, reducing the conductivity of the electrode, thereby reducing the high-rate discharge performance of the battery

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