Page 14 - Guide to Lithium-ion Battery Solutions
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Thermal Analysis



                                                                                                                                        Evaluation of shrinkage amount when the separator is heated
                  Moisture evaluation during heating of electrode active material


                                                                                                                                                                Thermomechanical Analyzer

                                                  Thermogravimetric Analyzers                                                                                   TMA-60

                                                  TGA-50 series                                                                                                 •   It is possible to measure the amount of shrinkage and shrinkage stress at each
                                                                                                                                                                  temperature
                                                  •   A small amount of water content can be detected                                                           •   Continuous recording of a sample's dimensional changes as temperature
                                                  •   Evaluation of connectivity by measuring the dehydration process                                             changes or over time in the order of µm
                                                    temperature                                                                                                 •   Tensile measurement, expansion measurement, and needle insertion
                                                  •  Measurement is possible in the atmosphere of air or nitrogen                                                 measurement are possible with one unit



                  It is important to control the moisture content in lithium-ion batteries because it affects their lifetime. The moisture   In general, the higher the shrinkage temperature and the smaller the amount of shrinkage, the safer it is. Thermo-
                  content of a material can be measured using a thermogravimetric analyzer (TGA).                                       mechanical analysis (TMA) was used to measure mainly the shrinkage of the separator.








                         Purpose                                        Samples                                                                Purpose                                        Samples

                  Measurement of moisture content in the         Positive/Negative electrode active material                            Measure the shrinkage of the separator          The two directions of the separator
                  active material                                                                                                                                                       called the MD (machine direction) and TD
                                                                                                                                                                                        (transverse direction)
                         Data                                                                                                                  Data



















                                                TGA Measurement of Electrode Active Materials                                                                               TMA Measurement of Separators


                         Result                                                                                                                Result


                  A weight loss rate at 200 °C was determined, and the moisture content was 0.033% and 0.214%, respectively.            According to the data, the start of shrinkage begins approximately between 80 °C and 100°C. In terms of the amount of
                                                                                                                                        shrinkage, the amount of shrinkage is larger in the MD direction than in the TD direction for both No. 1  and  2 .




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