Page 28 - Guide to Lithium-ion Battery Solutions
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Microanalysis





                  Observation of the shape of minute areas of battery material and measurement of conductive distribution                      Purpose


                                                                                                                                        Evaluation of element distribution and
                                                                                                                                        conductivity distribution in the same field of
                                                      Scanning Probe Microscope                                                         view

                                                      SPM-Nanoa    ™
                                                                                                                                               Samples
                                                      •   Observation near the interface and grasp of physical properties
                                                      •   Confirmation of the conductivity of minute parts                              Positive electrode sheet of the NCM
                                                      •   Observation of minute parts and evaluation of physical                        (lithium nickel manganese cobalt oxide)
                                                        properties are possible the air atmosphere



                  Positive and negative electrodes contain active materials, conductive aids, and binders. In order to improve the
                  conductivity between the active materials, a conductive aid is added, and each is bound and held by a binder.                Data
                  Evaluating how these elements are distributed in the positive electrode and how conductive paths are formed helps
                  improve the performance of Lithium-ion Batteries. We observed the surface shape and current distribution by measuring
                  the minute amount of current flowing through the conductive cantilever while applying a voltage to the positive
                  electrode.




                         Purpose                                        Samples

                  Observation of surface shape and               Positive electrode sheet of the NCM
                  measurement of potential distribution of       (lithium nickel manganese cobalt oxide)
                  minute parts of a positive electrode


                         Data
                                                        Applied Voltage : -2.7V










                                  Topography Image     Current Image     Current Image
                                                       (Low Contrast)   (High Contrast)
                         Result                                                                                                                Result


                  We observed the surface shape and current distribution by measuring a minute amount of current flowing through the    This data compares EPMA and SPM data within the same area. EPMA evaluates the distribution of elements whereas SPM
                  conductive cantilever while applying a voltage to the positive electrode. From the topography image, it is not possible   evaluates the distribution of shape and conductivity.
                  to determine where conductive aids, active materials, and binders are. However, in the current image, you can see the   By analyzing the state of materials from multiple instruments, it is possible to evaluate the uneven distribution and
                  three areas of red, yellow-green, and blue in order of conductivity. It can be estimated that the red areas are conductive   isolated state of a battery's material components, which can help with quality improvement and product development.
                  additives, the yellow-green areas are active materials, and the blue areas are binders.



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