Determination of twenty impurity elements in anode material lithium cobalt oxide for lithium-ion battery by inductively coupled plasma mass spectrometry

The analysis method of 20 impurity elements(Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Au, Pb and Bi) in lithium cobalt oxide by inductively coupled plasma mass spectrometry (ICP-MS) was discussed. The sample was dissolved via microwave digestion with nitric acid and hydrochloric acid. The sample solution was diluted with ultrapure water and then the impurity elements were directly determined by ICP-MS. Helium or hydrogen was introduced into octopole reaction system(ORS) to eliminate the mass interference of polyatomic ions from high salt matrix on testing elements. Mixed internal standard solution of ⁴⁵Sc, ⁸⁹Y, ¹⁰³Rh and ²⁰⁵Tl was selected to correct matrix interference and drifting. The detection limits of 20 testing elements were between 0.006 and 0.41 μg/L. Precision and accuracy test were conducted on lithium-ion battery anode material (lithium cobalt oxide) samples. The relative standard deviations (RSD) were in the range of 1.3 %-5.7 %. The recoveries of standard addition were 91 %-107 %. The proposed method was used to determine lithium cobalt oxide samples of different batches, and the results were consistent with those obtained by other methods (AAS, AFS and ICP-AES).