Lithium iron phosphate (LiFePO4), also known as LFP, is a novel, cobalt-free cathode material, which is increasingly used in lithium ion batteries (LIBs). To test the elemental purity of an LFP cathode matrix, a high purity LiFePO4 sample was prepared for analysis using microwave digestion. The Agilent 5800 VDV ICP-OES was used to quantify 28 trace elements plus Li, Fe, and P in the sample digests. Excellent calibration linearity was obtained for major and minor elements over a wide linear working range and the method detection limits for most elements in the solid were below 1 mg/kg. Recoveries of all trace elements spiked in the LiFePO4 sample before digestion were between 90 and 110%, confirming the accuracy of the sample preparation procedure and the ICP-OES method. The instrument was stable over 9 h, as shown by %RSDs of < 2.2% for all trace elements measured in the spiked LFP sample. The results confirmed the robustness of the 5800 ICP-OES for the routine analysis of high salt matrix samples.
The study has shown that the 5800 VDV ICP-OES can provide the accuracy, precision, and stability needed for the analysis of trace elements in new cathode materials. Download this application note to learn more.