Midstream battery production is where trace-level mistakes become expensive. In this phase, materials such as nickel sulfate, lithium carbonate, and graphite are refined for assembly, and QA teams must detect elemental and organic contaminants early. Missed impurities can degrade performance, raise production costs, or hold up delivery.
A recent webinar from Analytik Jena spotlighted how labs are using inductively coupled plasma optical emission spectrometry (ICP-OES) and total organic carbon (TOC) analysis to match the needs of battery quality control. The session focused on systems built for the harsh conditions of midstream samples, from salt-saturated cathode precursors to solvent-heavy electrolytes.
Handling Metal-Rich Matrices with ICP-OES
Figure 1: Silicon emission at 251.6 nm (orange line) appears clearly resolved from overlapping signals in nickel sulfate (top) and cobalt sulfate (bottom) using high-resolution ICP-OES.
ICP-OES remains a core tool in battery QA for its broad elemental coverage. But battery materials challenge even advanced systems. High salt loads, solvent-rich matrices, and aggressive acids such as hydrofluoric acid (HF) can distort spectra and damage components.
The webinar introduced the PlasmaQuant 9100 Elite, designed to address the analytical challenges of battery materials. It can resolve spectral features just 2 picometers apart in the 200 nm deep UV range, separating closely spaced emission lines even in metal-rich matrices (Figure 1). The torch assembly uses HF-resistant materials to reduce wear, while spectral correction tools help extract clean signals from organic-rich electrolytes.
An application note presented in the webinar detailed how the system analyzed nickel sulfate, HF-digested anodes, and ethanol-based electrolytes. Across all sample types, recoveries held between 90–110% with RSDs under 5%. Analysts ran these workflows without customizing standards to each matrix or adding cleanup steps.
The system’s dual plasma views—axial and radial—let analysts tailor ICP-OES detection to each element. Axial view improved sensitivity for trace-level contaminants in cathode salts, while radial view stabilized signals from elements prone to ionization, such as sodium and potassium. Both views ran in the same method, enabling accurate results without switching setups.
Detecting Organic Contaminants with TOC
While ICP-OES reveals elemental issues, TOC systems track residual solvents, surfactants, and process additives. These organic traces, common in cathode salts, can degrade long-term battery performance. Detection thresholds typically fall below 10 mg/L—difficult to reach when salt levels are high and combustion becomes unstable.
To tackle this, Analytik Jena’s multi N/C 3300 combines high-temperature oxidation with physical separation. A quartz crucible captures salt residue before it reaches the catalyst, preventing fouling during analysis. The system automatically removes inorganic carbon and subtracts background signal, isolating only the organic content.
The webinar highlighted an application note that showed the system’s effectiveness across five cathode salts, including lithium carbonate, cobalt sulfate, and manganese sulfate. In cobalt sulfate tests, the multi N/C 3300 returned precise, repeatable TOC values across multiple replicate injections, with recoveries between 94% and 110% and RSDs below 5% (Figure 2).
Figure 2: TOC results for cobalt sulfate show consistent values across 10 × 3 replicate injections.
HF-Resistant QA for Anode Materials
Anode testing often involves HF digestion, especially for graphite and silicon-based materials. These corrosive samples can stress both optical systems and hardware components.
Data from a related application note described how the PlasmaQuant 9100 Elite measured trace metals such as iron, copper, and aluminum in HF-digested graphite-silicon mixtures. Chemically resistant components, including tubing, ceramic torch parts, and reinforced valves, tolerated repeated HF exposure without damage. High-resolution optics and automatic baseline correction resolved spectral overlaps without manual tuning and supported stable operation.
Analyzing Complex Electrolytes
Figure 3: Spectral correction removes background interference near the Hg 184 nm emission (orange line), revealing a clear ICP-OES signal in the electrolyte matrix.
Electrolyte samples introduce new challenges. Solvent-rich formulations—such as those containing ethanol and fluorinated compounds—can distort optical signals and wear down sensitive components.
A featured application note illustrated how the PlasmaQuant 9100 Elite handled lithium hexafluorophosphate electrolytes, which can generate hydrofluoric acid and pose risks to both instrumentation and lab safety.
In addition to its HF-resistant design, the system also addressed spectral interference using CSI (Correction of Spectral Interferences), a software algorithm that subtracts background signals from solvent-rich matrices. This correction enabled accurate detection of trace elements such as mercury and cadmium, with detection limits as low as 0.01 mg/kg and QC recoveries between 94% and 109% (Figure 3).
Key Takeaways for Battery QA Labs
The webinar emphasized how hardware choices—from optical systems to chemical durability—shape how labs manage complex matrices. Highlights included:
- High Spectral Resolution ICP-OES: The PQ 9100 Elite optical system provided reliable interference-free analysis of targeted trace elements
- TOC detection stayed below 10 mg/L: The multi N/C 3300 handled high-salt cathode salts with consistent precision.
- Recoveries hit 90–110% with RSDs under 5%: Performance held steady across salts, acids, and solvents.
- Hardware endured aggressive matrices: HF digests and solvent-heavy electrolytes didn’t require added maintenance.
Watch the full webinar to see these results in action.
Meet the Experts
 | Kilian Schneider Kilian Schneider holds a PhD in chemistry with a focus on ultrafast pump-probe spectroscopy in biological systems. He joined Analytik Jena in June 2021 as an Application Specialist and became a Product Specialist for ICP-OES in April 2024. His expertise includes atomic absorption spectroscopy (AAS), ICP-OES, and analytical chemistry. He also holds a Master’s degree from Friedrich Schiller University Jena and has completed certifications in business administration, project management, and communication. |
 | Bernd Bletzinger Bernd Bletzinger received his MS in Technical and Analytical Chemistry at Friedrich Schiller University Jena & Dublin City University in Ireland. He has been with Analytik Jena since 2006, first as an application specialist, then as a product specialist, and is the product manager for the TOC/TNb product line. |
