Slot-die coating is widely used in the preparation of negative electrodes for lithium batteries. The thickness of the negative electrode has a significant influence on the battery performance and lifespan, and different manufacturers have different requirements for its thickness. In order to reduce the waste caused by trial and error in the electrode preparation process, a prediction model for the negative electrode thickness was established and verified through simulation and experiments. Based on the Landau–Levich film equation and the Ruschak model, a high-precision prediction model was constructed by taking into account the influence of factors’, such as temperature and slurry, spreading characteristics on the coating thickness. The minimum coating thickness and its influencing factors were explored. Meanwhile, the simulation analysis of the coating thickness was performed, and the theoretical values of three common process parameters were compared with the simulation results, showing a deviation of only 2.9%. An experiment on predicting the thickness of the negative electrode of lithium batteries was conducted. Thickness measurements were performed on the samples prepared through the experiment and compared with theoretical values. The accuracy rate of this thickness prediction model can reach 98.75%.
As a new all-solid-state instrument, fiber optic gyroscope (FOG) is increasingly used as a core component of inertial measurement unit because of its high stability, low cost, impact resistance and good dynamic performance. As the sensitive component in FOG, fiber optic coil is very susceptible to transient temperature gradient, which becomes a key factor that restricts the development and precision of FOG. The non-reciprocity error of the fiber coil caused directly by the temperature gradient has been studied by many researchers. While the non-reciprocity error caused by thermal stress is rarely concerned. Studies have shown that proper winding pattern and good winding quality can greatly reduce the Shupe error of the fiber coil. However, the phenomenon that the Shupe error peaks at different temperature points are different in size is confused, even under the same temperature gradient. In the process of derivation of the thermal stress Shupe error model, the thermal stress induced Shupe error is the main cause of the difference in the peak of the FOG at different temperature points.By studying the influence of material parameters of coating adhesive in the fiber coil on FOG, the purpose of improving the performance of the fiber optic gyroscope can be achieved. Based on the mathematical model of Shupe error, the non-reciprocity error of the FOG caused by thermal stress is analyzed. The distribution of thermal stress of fiber coil with different coating adhesive parameters (Young's modulus and thermal expansion coefficient) was obtained by ANSYS finite element analysis software. The influence of temperature sensitivity of coating adhesive parameters on thermal stress of FOG and Shupe error was studied. The simulation results show that both the Young's modulus and the thermal expansion coefficient of the coating adhesive affect the magnitude and uniformity of the thermal stress induced Shupe error, but the degree and mode of influence are different. The absolute value of the thermal expansion coefficient and the gradient over temperature will directly affect the non-uniformity of the thermal stress induced Shupe error. In general, the gradient of the thermal expansion coefficient with temperature lead to a negative correlation trend with the peak value of the Shupe error. While, the temperature sensitivity of the Young's modulus also indirectly affect the non-uniformity of Shupe error. When the coefficient of thermal expansion changes rapidly with temperature, the changing Young's modulus will intensify the non-uniformity of Shupe error. By studying material parameters of coating adhesive, the variation law of Shupe error can be obtained and it is possible to optimize coating adhesive selection principle of coating adhesive and reduce the non-uniformity of thermal induced non-reciprocal bias, which is of great significance in the application of FOG. Finally, the coating adhesive of fiber coil with suitable material parameters was selected by the selection principle of coating adhesive obtained in this paper.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
