Detecting Oversized Particles in Battery Materials – A New Era of Sensitivity

In today’s competitive battery manufacturing landscape, performance, safety, and reliability are non-negotiable. The materials that form the heart of a lithium-ion battery — its cathode and anode — are carefully engineered to maintain a precise, narrow particle size distribution. This uniformity is critical for achieving consistent electrochemical performance, high energy density, and long cycle life.

However, the manufacturing process is not immune to variations. During material handling, mixing, and processing, unwanted oversized particles can slip in. These may be large agglomerates of the intended material or entirely different contaminants. Even at extremely low concentrations, these particles can create localized hotspots within the cell. Such hotspots can lead to accelerated material degradation, loss of capacity, shorter operational life, and, in severe cases, safety hazards such as thermal runaway. Given the growing demands from electric vehicle (EV) manufacturers, renewable energy storage systems, and portable electronics, the ability to detect oversized particles at the earliest possible stage has become a critical quality control criterion.

The limitations of traditional laser diffraction

For decades, laser diffraction has been the industry’s preferred method for measuring particle size distributions in powders and slurries. It offers rapid, reproducible results and is ideal for routine quality assurance. However, its sensitivity to rare, oversized particles is limited. When only a handful of such particles are present, their scattering signal can be easily overwhelmed by the much stronger signal from the bulk particle population.

In practical terms, this means traditional systems often struggle to detect oversized particles unless they exceed a threshold, which is typically hundreds of particles per million (PPM). For industries like battery manufacturing – where even a few contaminants can cause a significant problem – this limitation poses a challenge.

The mastersizer 3000+ with Size Sure and Hydro Insight

To overcome these challenges, the Mastersizer 3000+ introduces two powerful technologies: Size Sure adaptive laser diffraction and Hydro Insight dynamic imaging.

Size Sure enhances detection sensitivity by capturing 10,000 diffraction frames per second and separating the signal into two components:

• Steady state: representing the bulk particle population
• Transient state: capturing rare, short-lived scattering events caused by oversized/anomalous particles

By isolating these transient events, Size Sure can detect oversized particles with high sensitivity – almost a tenfold improvement over classical diffraction — without increasing the measurement time.

Hydro Insight adds another dimension: visual verification. This dynamic imaging system captures high-resolution images of individual particles, enabling analysts to distinguish between agglomerates and true contaminants. It can detect oversized particles at concentrations as low as 1 particle per million, making it an invaluable tool for root cause analysis and supplier quality control.

Case Study – LNCA Cathode Material

In a controlled evaluation, Lithium Nickel Cobalt Aluminium Oxide (LNCA) cathode material was tested in its pure form and spiked with known concentrations of spherical glass contaminants. The results were clear:

• Classical Laser Diffraction detected oversized particles only at concentrations ≥100 particles per million.
• Size Sure reliably detected them at concentrations ≥10 particles per million.
• Hydro Insight identified them at ≥1 particles per million, with clear visual confirmation.

The combination of Size Sure and Hydro Insight provided a complete picture — rapid detection for routine QA/QC and definitive imaging for in-depth investigations.

Benefits for battery manufacturers

The implications for the battery industry are significant:

• Enhanced safety: early detection reduces the risk of hotspot formation and potential thermal runaway.
• Improved yield: fewer defective cells reach final assembly.
• Extended product life: minimising degradation caused by contaminants.
• Cost savings: preventing failures before materials are incorporated into high-value battery cells.

Join our webinar – 10th September

Discover how Size Sure and Hydro Insight on the Mastersizer 300+ can revolutionize particle detection in battery materials. Our experts will share real-world case studies, demonstrate how these tools enhance detection sensitivity, and explain how early intervention can prevent costly failures.

Register today to elevate your quality assurance and quality control processes – and set new standards for battery manufacturing excellence.