Monitoring and Controlling the Electrode Particle Characteristics and Viscosity of Battery Slurries

The impact of electrode particle size and shape on battery slurry viscosity

Using Morphologi G3 to monitor and control the electrode particle characteristics and viscosity of battery slurries

Introduction

Batteries are ubiquitous in modern life and our reliance on them has never been greater. Therefore, ensuring optimum battery performance through manufacturing control is of increasing significance. In previous application notes we have discussed the importance of controlling the size of particles used in the manufacture of battery materials [1] and the impact of carbon microstructure in graphite electrodes on battery performance [2]. Shape is also an important factor to consider and control, as irregular shaped particles not only reduce packing density, but they can lead to the formation of a high viscosity electrode slurry. In this third application note on batteries, we consider the role of size and shape on the viscosity of the electrode slurry

Electrode composition

The typical structure of a battery electrode is given in Figure 1. The electrode is usually fabricated by applying a slurry of particles in suspension onto a metal foil.

The slurry in question is composed of electrode particles (anode or cathode), small carbon particles to aid conduction, and binder material (composed of solvent and polymer) to hold the structure together. The concentration of particles in the slurry is high, representing between 20-40 % of the total by weight. Consequently, the particle properties have a significant impact on the physical properties of the resultant slurry.