How to Digest Lithium-Ion Battery Materials for ICP-OES Analysis

Research and Development departments are steadily developing alternative materials for next generation batteries with increased storage capacities, faster charging and longer overall lifespan. In addition, production and QC requirements are becoming more stringent for Li-ion battery manufacturers as well. As all batteries reach the end of their useful life at some point, recycling and waste management companies take them over to perform high-quality recycling of their core components, which is essential to reduce the use of primary raw materials.

Consequently, it is important to determine the exact and consistent element composition of the electrode raw materials during development and quality control in battery manufacturing, as these affect the performance and possibly safety of the end products. In addition, concentrations of impurity levels must also be accurately measured in the battery components. Ageing of Li-ion batteries represents a major drawback, which affects as a complex multi-material process practically all cell components. Numerous ageing mechanisms occur due to degradation processes of individual materials and their interactions with each other. Thus, quantitative information about the lithium or transition metal distribution in the bulk or the surface of the electrodes is needed to understand and to set countermeasures to minimize the negative effects on battery performance.

Spatially resolved analysis of individual material particles is often combined with inductively coupled plasma optical emission spectroscopy of larger sample quantities, wherein this technique requires adequately digested samples. Microwave-assisted acid digestion is the optimum tool to prepare these very different samples. As the materials differ a lot, appropriate digestion methods are chosen depending on the sample matrix and analytes of interest.

The new Rotor 20SVT50 in Multiwave 5000 provides the already well-established SmartVent technology, but at higher pressure and temperature limits. Controlled overpressure release is a safe and convenient operation mode, as target temperatures of up to 250 °C can be reached and maintained.

With up to 20 samples in one single run, Rotor 20SVT50 offers unrivaled efficiency. The convenient tool-free handling and the compact vessel design to ease weighing, cleaning and operation make Rotor 20SVT50 the ideal candidate for demanding samples in Multiwave 5000.

In order to demonstrate its suitability a range of Li-ion battery components were digested in several runs. Afterwards the elemental concentrations were determined via ICP-OES.