Conveying and mixing characteristics of Lithium-ion battery anode material particles in horizontal pipes

Abstract

Anode materials (graphite particles) require pneumatic conveying for use in lithium-ion battery fabrication. Particle stratification often occurs during this process, leading to non-uniform physical and chemical properties. These non-uniform properties negatively impact battery performance. To address this, the use of a threaded pipe section is proposed to enhance particle-mixing performance. The flow field characteristics and particle motion behavior within both threaded and straight pipes were examined through numerical simulation and experimentation under varying operating conditions.

The results show that the threaded pipe section alters the gas flow, reduces particle stratification, significantly improves particle mixing, and promotes more uniform conveying. Increasing the airflow velocity in the threaded pipe causes greater particle disturbance compared to the straight pipe at the same conveying concentration, leading to a more even distribution and better mixing of large and small particles. When the conveying velocity is between 3 m/s and 7 m/s, the mixing performance 1 m from the inlet in the threaded pipe improves by 44–57 % compared to the straight pipe. Similarly, the threaded pipe continues to demonstrate superior mixing performance as the conveying concentration increases. At concentrations ranging from 1 % to 5 %, the mixing performance 1 m from the inlet improves by 37–55 % when using the threaded pipe compared to the straight pipe.