CFD modelling of the effects of local turbulence intensification on synthesis of LiFePO₄ particles in an impinging jet reactor

LiFePO₄ particles has been widely recognised as a promising positive electrode material for rechargeable lithium-ion batteries due to its excellent properties. Confined impinging jet reactor was recently proposed to replace the stirring reactor for synthesising LiFePO₄ nanoparticles. It has been recognised that the use of impinging jet reactor can provide higher mixing intensity and shorter residence time for the reaction so as to improve the synthesis efficiency. The present work conducts CFD simulations to gain a better understanding of the mechanism of LiFePO₄ synthesis in an impinging jet reactor, focusing on the effects of local turbulent kinetic energy and turbulence dissipation rate distributions in the impinging core region on the mixing of two reactant streams and reaction kinetics. Compared with the experimental results, it is revealed that larger turbulent kinetic energy in the impinging centre region can effectively promote the mixing of reactant streams but the reaction completeness will be reduced due to shortening of reaction time if a large turbulence dissipation rate occurs in the impinging core region. It is also indicated from the simulations that the reaction completeness of LiFePO₄ synthesis significantly depends on the turbulent mixing and turbulent kinetic energy distribution but less on reaction kinetics.