Electrode materials

Selection of both anode and cathode materials for batteries plays a fundamental role in the design of a successful cell.

Electrode properties impact on almost all aspects of cell performance including charge & discharge rates, cycle life, capacity and energy density, and have important implications for handling and manufacture.

Material characterisation

• Particle mass distribution

• Effective density

• Agglomeration strength

• Particle size

Optical techniques

Traditional techniques have used optical sizing of powder materials which have been suspended in a liquid. Insights available via this optical approach may be compromised due to both the technique's sensitivity to both material and a complex response to non-spherical particles, which are common in nano-engineered materials. The choice of liquid may also affect dispersion, and so measurements may not be representative of material as handled in manufacture.

Novel technique

The Cambustion M2AS (launched 2022) enabled direct measurement of particle masses in an aerosol (suspended in a gas).

The M2AS classifies particles by mass, and measures their physical size. This allows measurement of particle effective density, and how this varies with particle size, yielding a fingerprint for the particle structure.

Dispersion and deagglomeration

It is essential that the generation of aerosol from powder is well controlled, since deagglomeration can occur as part of the process.

Use of a system from femtoG allows both dispersion and deagglomeration to be well controlled, while variation of the deagglomeration shear stress allows the M2AS to establish the strength of powder agglomerates, an important characteristic for electrode manufacture.

M2AS insights and advantages

• Particle size measurements are independent of material optical properties

• Simultanous measurements of particle size, mass and effective density vs size

• Determination of powder agglomerate strength

• Particle mass is well defined and traceable, unlike many instrument specific definitions of size

• Compatible with metal oxides, carbon, silicon powders and more

• Determination of coating material distribution between surface coating and forming separate particles