Numerical and experimental study on the calcination process of the raw materials of lithium battery cathode

Abstract

Ternary cathode materials hold great promise in the lithium battery market, yet analyses regarding their calcination process in simulation and on-site experimentation, are few. In this paper, a multiphysics-coupled computational fluid dynamics (CFD) model was developed to simulate the primary calcination process (The actual production process is divided into two calcinations, because the production conditions affect the measurement, this paper focuses on the analysis of the primary calcination process) of lithium battery raw materials (namely, Ni0.8Co0.1Mn0.1(OH)2 and LiOH∙H2O mixture, hereinafter referred to as raw materials) under oxidizing atmosphere conditions. The process involves fluid flow, heat and mass transfer, and chemical reactions. A new method which combined steady-state calculation with transient calculation was adopted. Firstly, the steady-state simulation of the whole furnace was carried out, and then the transient simulation of each furnace area is carried out consequently, the heat and mass transfer processes of raw materials in different furnace zones were solved, ultimately achieving the simulation of the entire furnace calcination process. On-site black box experiments were performed to obtain the temperature evolution during the calcination process. Meanwhile, compared with the calculated results of the model, it was found that the average hit rate with an absolute error of less than ±20 °C above 300 °C can reach 86.9%, confirming the applicability of the model. The multiphysics-coupled CFD model simultaneously solves the oxygen concentration. The process parameters were analyzed based on the model, providing a fundamental method for the improvement of the performance of lithium battery cathode materials calcination process.