How XRF compares to ICP for battery elemental analysis 

par Umesh Tiwari, Friday, 10th January 2025

XRF vs ICP: what’s the best choice for battery elemental analysis?  

Batteries are essential to the energy transition, but this means the pressure to increase the rate of production is immense. To ensure consistent quality, manufacturers use elemental analysis to monitor the presence of materials like nickel, manganese, and cobalt (NMC) either in the raw inputs or during the production process.  

However, how can this analysis keep up with the increased throughputs that the industry’s growth demands? In many industries, there are two main choices when it comes to elemental analysis: inductively coupled plasma (ICP) spectroscopy or X-ray Fluorescence (XRF). Read on to find out about the limitations of ICP in high-throughput environments and why XRF is a powerful alternative.  

Overview: XRF vs. ICP 

  • XRF (X-ray fluorescence): 
    • XRF is a non-destructive technique that determines the elemental composition of solid, liquid, or powdered samples. 
    • Does not need frequesnt calibrations, easy to operate and maintain.
    • It’s particularly effective for in-line quality control in battery production due to its speed, simplicity, and ability to analyze a broad range of elements and concentrations with minimal sample preparation​. 
  • ICP (Inductively Coupled Plasma spectroscopy): 
    • ICP is a destructive elemental analysis technique that requires dissolving samples in acid for analysis.
    • ICP requires very frequent calibrations and flow of gases like Ar.
    • Known for high sensitivity and precision, ICP is excellent for trace elements. However, the long time it takes for samples to dissolve and the care a specialized operator must take in handling the aggressive acids make it unsuitable for in-line quality control.  

For battery elemental composition analysis, the key difference between ICP and XRF lies in their respective sample preparation requirements. This is what makes the difference between XRF’s tight feedback loop and easy operation, and ICP’s longer feedback loop and need for a specialized operator.  

Taking a closer look at both techniques, we can find further differences in three main areas: instrument calibration, analysis speed and automation, and cost-effectiveness. 

The strengths of XRF instrument calibration 

XRF is fundamentally a comparative technique. This means that calibration standards are needed, as the instrument measures samples ‘against’ these standards to trace elements and interpret even unknown samples accurately. A wide calibration is generally preferred, as it allows accurate analysis across diverse sample types, which is key for battery cathode manufacturing.  

We use certified reference materials (CRMs) as calibration standards. However, only one commercial CRM exists for NMC. That’s why we’ve developed a calibration kit of synthetic reference materials produced in our ISO-accredited facility in the UK. The benefit of XRF is that once an instrument is calibrated with such standards, the calibration remains stable for months or even years, with minimal drift correction required! 

In contrast, ICP often requires narrow calibration ranges to improve accuracy at specific concentration levels. ICP also recommends regular, often weekly recalibration and drift corrections, making it more labor-intensive especially in high-throughput environments.  

XRF’s speed and automation 

ICP demands extensive and careful sample preparation due to the use of dangerous chemicals like sulfuric acid and hydrofluoric acid. As such, ICP instruments are typically limited to off-line analysis in the lab. Despite its excellent precision, ICP is thus less suited for on-site analysis in a production setting than XRF. 

Indeed, XRF instruments excel at on-site analysis both for battery production and recycling. For example, the Epsilon 4’s benchtop format and robust design means it can be easily set up near the process line, and operators can analyze samples quickly, simply, and with minimal sample preparation.  

Read the app note

For more high-precision applications, samples can be prepared as fused beads via lithium borate fusion. The Eagon 2 automatic fusion machine enables this kind of sample preparation to be completed in 30 minutes, adding only a small amount of time to the analysis but greatly enhancing its precision.  

We performed an XRF experiment with fused beads using the Zetium XRF analyzer. Read the application note below to learn more.  

Read the app note

For liquid processes, XRF can even be integrated into the production line with the Epsilon Xflow. Operators can therefore obtain real-time data concerning the effects of their process parameters, helping reduce waste and improve output quality through data-driven decisions.  

XRF: A cost-effective solution 

The simplicity and stability of XRF calibrations make it a cost-effective choice: maintenance is required less often, and instruments have more weekly uptime than with ICP. One of the greatest cost benefits of XRF, however, is its risk-free ease of use. Investing in an ICP instrument also means hiring an ICP specialist to perform sample preparation; investing in an XRF instrument does not. XRF instruments thus have a much lower cost of operation.  

XRF thus stands out as the more versatile, economical, and productive technique for the fast-paced battery manufacturing industry.  

Want to see how XRF works in practice? Then watch this webinar on XRF analysis in the process control of battery cathode manufacturing! 

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