Abstract: During the preparation of lithium battery slurry, poor uniformity and powder agglomeration significantly impact battery performance. This study investigates the effects of rotation speed, stirring direction, ratios of impeller diameter to tank diameter, and screw pitch on the flow field distribution, circulation characteristics, shear properties, concentration distribution, and specific mixing energy using computational fluid dynamics (CFD). The results indicate that in counter-rotational stirring mode, the vortex center is notably higher, demonstrating stronger fluid circulation characteristics. The complex vortex structures and cross-flows effectively enhance shear stress. Although specific mixing energy exhibits a positive correlation with impeller speed, counter-rotational stirring exhibits advantages in reducing energy dissipation. Compared to co-rotational stirring, counter-rotational stirring achieves an energy saving rate of 21.7% to 60.7% within the range of 100 to 400 r/min. Regarding mixing uniformity, low-speed co-rotational stirring performs better, while high-speed counter-rotational stirring achieves superior mixing uniformity. Increasing the impeller diameter ratio can effectively boost axial and radial velocities and enhance shear stress, but it also increases specific mixing energy, thereby decreasing mixing efficiency. Increasing pitch enhances axial and radial velocities, improves mixing uniformity, reduces flow resistance, and boosts mixing efficiency. However, excessively large ratios of impeller diameter to tank diameter and impeller pitches can lead to uneven flow and affect the uniform distribution of solid particles.

Key words: double planetary mixer, mixing characteristics, blade structure, numerical simulation

摘要： 在锂电池浆料的制备过程中，均匀性差和粉末团聚等问题显著影响电池性能。本工作采用计算流体力学研究双行星螺杆式搅拌器的混合特性，考察了转速、转向、桨径比和螺距对锂电池浆料的流场分布、循环特性、剪切性能、浓度分布及单位体积混合能的影响。结果表明，反向搅拌模式下涡流中心明显偏高，展现出更强的流体循环特性。复杂的涡流与交错流动有效增强了剪切应力。尽管单位体积混合能与搅拌桨转速呈正相关，反向搅拌仍在降低能量耗散方面表现出优越性，与同向搅拌相比，在100~400 r/min范围内，反向搅拌的能量节省率可达21.7%~60.7%。在混合均匀性方面，低速下同向搅拌效果较好，高速下反向搅拌更为均匀。增大桨径比能有效提升流体的轴向和径向速度，增强剪切应力，但同时导致单位体积混合能上升，混合效率降低。螺距增大提升了轴向和径向速度，改善了混合均匀性，并降低了流动阻力，提高了混合效率。过大的桨径比和螺距会导致流动不均匀，影响固体颗粒的均匀分布。

关键词: 双行星搅拌器, 混合特性, 桨叶结构, 数值模拟