Novel nanoparticle mixing approach for the production of solid-state battery hetero-agglomerates in vibrated fluidized beds

Abstract

A vibrated fluidized bed with microjet assistance is utilized to mix heterogeneous submicron-sized battery materials. This process aims to improve the homogeneity and electrochemical performance of a solid-state cathode composite consisting of LiFePO₄ (LFP), Li₃InCl₆ (LIC) and carbon black (CB). A downwards directed microjet was employed to enhance fluidization and mixing quality. The research involved a parametric study, examining various vibration intensities, microjet nozzle sizes, and fluidization times to determine the optimal conditions for achieving a homogeneous composite on the microscale. Scanning electron microscope (SEM) and focused ion beam SEM (FIB-SEM) imaging were used to assess the mixing quality and confirm the formation of heteroagglomerates. Assisted fluidization alone produces composites with inferior mixing quality, whereas a microjet significantly improves mixing. Electrochemical testing reveals that a vibrated fluidized bed alone is inadequate for mixing submicron-sized particles for battery applications, whereas the microjet enables the mixing and ionically bound active material.