Case 1: Pole piece coating**
The coating process is very important in the electrode process, and the coating quality seriously affects the quality (areal density) of the battery electrode piece and the subsequent process. Through coating, the structural design of the coated gasket can be optimized, the verification time can be shortened, the gasket development cost and the slurry use cost can be reduced. It can also optimize the selection of coating process parameters, establish a digital coating model, and shorten the ramp-up time of the coating process. At present, we have mastered the technical difficulties of coating, and constructed a multiphase flow model of non-Newtonian fluid slurry with internal and external flow fields, which can accurately reflect the wet film thickness distribution of the coating slurry at the micron level, and the accuracy error is within 8%. At present, it has been used for many times in process coating problem solving analysis, and has played a good role in virtual verification.
Case 2: Laser welding dynamic heat**
*Reason: In the debugging stage, the PP plastic on the back of the adapter was scalded by the final welding of the positive and negative electrodes, and the positive electrode was more serious, and the edge of the negative electrode plastic was shrinked.
*Test: It is necessary to measure the temperature rise of the back of the adapter during welding, and measure the thickness of the melted plastic to calculate the shrinkage.
*The maximum temperature of the PP is 294 when the lower boundary of the PP is increased by the gap between the gelatin, and most of the high temperature areas are in the temperature range of 264-240, and the measured temperature is 2457 The temperature results are very close, indicating that the model is realistic and can be used for the next step.
Simulation process:
Fluent can successfully simulate the change process of dynamic heat source during the welding process, and obtain the transient change of the temperature field inside the structure under this working condition. Subsequently, it can be used for the analysis of thermal stress and deformation of the structure.
Case 3: Roller oven moving grid heat**
In the wet coating process, the positive electrode or negative electrode material is coated on the surface of the positive electrode or negative electrode current collector, and then dried and laminated together, and the main equipment of the drying process is the oven, which plays a vital role in the production efficiency of the electrode piece and the quality of the coating, and the oven is also one of the lithium battery production equipment with the highest energy consumption, and in the wet coating, although the application of NMP solvent brings good to the positive and negative electrode materials, But at the same time, it also brings problems such as the need to control security and centralization.
The "temperature-heat dissipation power relationship" of the pole piece is decoupled and output as an edge strip input to the pole piece moving grid boundary simulation.
Using Fluent motion mesh technology and thermal analysis functions, the temperature changes of the electrode pieces in the oven can be accurately analyzed**, providing a reference for the optimization of process parameters.
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