Dibyendu Mukherjee1,Ravi Pamu1,Seyyed Ali Davari2,Devendrasinh Darbar3,4,Ethan C. Self4,Jagjit Nanda4
The University of Tennessee, Knoxville1,California Air Resources Board2,Tennessee Tech University, Cookeville3,Oak Ridge National Laboratory4
Dibyendu Mukherjee1,Ravi Pamu1,Seyyed Ali Davari2,Devendrasinh Darbar3,4,Ethan C. Self4,Jagjit Nanda4
The University of Tennessee, Knoxville1,California Air Resources Board2,Tennessee Tech University, Cookeville3,Oak Ridge National Laboratory4
Recent years have seen a surge in the demand for high-performance battery electrode materials for automotive, and various electronic device applications. Improving battery performance requires precise knowledge on the structure-composition properties of active electrode materials. To this effect, quantitative and precise estimation of the composition of advanced electrode materials, containing trace amounts of dopants provide immense value towards developing next generation high-capacity battery materials. Herein, we demonstrate the application of calibration-free Laser Induced Breakdown Spectroscopy (LIBS) as a powerful analytical tool for rapid and reliable quantitative spectrochemical characterizations of layered Li metal oxide cathodes containing Mo and Cr dopants (<5 at%). Specifically, we employ LIBS using an internal calibration methodology to establish the quantitative elemental ratios of major (Ni, Mn, Co) and trace dopant (Cr, Mo) transition metals to the bulk Li contents in diverse cathode material samples such as, LiNi<sub>0.5</sub>Mn<sub>0.5</sub>O<sub>2</sub> (NM-50/50), LiNi<sub>0.33</sub>Mn<sub>0.33</sub>Co<sub>0.33</sub>O<sub>2</sub> (NMC), LiNi<sub>0.317</sub>Mn<sub>0.317</sub>Co<sub>0.317</sub>Cr<sub>0.05</sub>O<sub>2</sub> (Cr doped NMC), and LiNi<sub>0.5-x/2</sub>Mn<sub>0.5-x/2</sub>Mo<sub>x</sub>O<sub>2 </sub>(x = 0.03, 0.04, 0.05) (Mo doped NM-50/50) that were synthesized via sol-gel routes. Our results indicate good agreement between the LIBS estimated elemental compositions and the nominal stoichiometric values. Ex-situ LIBS characterizations presented here paves the path for future high-efficacy application of calibration-free quantitative LIBS for rapid in-situ analyses of elemental composition changes in battery electrode materials under operation that need not resort to off-site analytical techniques requiring cumbersome sample preparations and/or, external standards.