QUALITATIVE DETERMINATION METHOD FOR CARBONATE IN POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a qualitative determination method by which carbonate content in an active material for a lithium secondary battery positive electrode material can be quickly and easily found. SOLUTION: An absorption spectrum of an active material is found by an FT.IR method, and the area S800 of the absorption peak existing in a range of a wave number of 890 to 840cm-1 is found, and the lithium carbonate content W is found by an expression (S800 =0.2234W-0.0794). In this method, it is desirable that infrared absorption measuring pottasium bromide is added to active material powder and is uniformly mixed so that transmissivity (%) in a wave number 4000cm-1 becomes about 10%, and it is also desirable that integration of measurements not less than 20 times is performed when FT.IR is measured.