JP6472014B2 - Time-of-flight secondary ion mass spectrometer internal current voltage application measurement mechanism - Google Patents

Description

  The present invention relates to an apparatus such as a time-of-flight secondary ion mass spectrometer (TOF-SIMS) in which a sample for measurement needs to be placed in a special environment such as a vacuum.

An apparatus such as TOF-SIMS places a sample in a high vacuum state of about 10 ⁻⁷ Pa, and performs mass analysis of the sample and measurement of element distribution mapping.

Fig.1 (a) and FIG.1 (b) are schematic which shows an example of the measurement by such TOF-SIMS. In FIG. 1A, reference numeral 1 denotes a measurement chamber called a chamber provided in the analyzer, which is maintained in a high vacuum state of about 10 ⁻⁷ Pa. Then, the measurement solid sample 20 is sandwiched between a pair of opposing conductive fixing members 10A and 10B. A voltage is applied to the sample from a high-voltage power source described later through this fixing member, and mass spectrometry is performed. In addition, an ammeter for measuring the amount of primary ion irradiation during measurement may be provided.

  In FIG. 1A, a high-speed ion beam, that is, a primary ion is made to collide with the solid sample 20 and the components on the surface of the solid sample are blown off by a sputtering phenomenon. The positively or negatively charged ions generated at this time, that is, secondary ions are scattered in one direction by an electric field and detected at a position separated by a certain distance. During sputtering, secondary ions of various masses are generated depending on the composition of the solid surface, but ions with smaller masses fly faster, and conversely, ions with larger masses fly slower. The mass of secondary ions generated can be calculated by measuring the time until detection at a position apart by a certain distance. In this way, mass spectrometry can be performed. In the configuration as shown in FIG. 1A and FIG. 1B, mass analysis of a cross section is possible by selecting an all solid LIB as the solid sample 20. Furthermore, it is possible to take out the solid sample 20 from the chamber 1 and connect it to a current-voltage characteristic measuring instrument such as a potentio galvanostat having a counter electrode and a working electrode to perform electrochemical measurement.

  As described above, in the conventional method, the sample is generally placed in an inert atmosphere, that is, a high vacuum for mass analysis, and then the sample is taken out and the electrical characteristics are measured subsequently to the mass analysis. is there. Therefore, complicated operations such as movement of the sample and change of wiring for measurement are required. Since the LIB sample deteriorates in the atmosphere, such work is not preferable, and as a result, there is a problem that it is impossible to accurately correspond to the result of the LIB electrochemical test and the change in element mapping.

JP2013-160588 JP2014-037120

  In view of the above problems, the object of the present invention is to incorporate a current-voltage application mechanism into a time-of-flight secondary ion mass spectrometer (TOF-SIMS) and externally connect through a metal electrode that also serves as a sample fixing plate. Current voltage in a time-of-flight secondary ion mass spectrometer (TOF-SIMS) for applying DC and AC current voltages to a measurement sample with a potentio galvanostat and performing current voltage measurement tests and elemental analysis mapping at once. It is to provide an application measurement mechanism.

  In addition, a lithium-ion battery (LIB) sample, in which internal ions move when energized, can be subjected to a current-voltage test in a TOF-SIMS measurement chamber (in an inert atmosphere) maintained in an ultra-high vacuum, and the LIB sample is exposed to the atmosphere. Therefore, the time-of-flight secondary ion mass spectrometer (TOF) is capable of making a one-to-one correspondence between the results of the LIB electrochemical measurement test and the changes in elemental analysis mapping. -SIMS) It is an object to provide an internal current voltage application measurement mechanism.

  A time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism according to the present invention for solving the above-described problems and achieving the object is a sample holder having at least two electrodes. And a current / voltage application source for performing a current / voltage application test, and the sample holder is configured to hold the sample, and the TOF-SIMS measurement by TOF-SIMS and the current voltage to the sample by the current / voltage application source And a measurement of electrical characteristics associated with the application of the sample in a time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism.

  The current / voltage application test may be LIB charge / discharge characteristic measurement, impedance measurement, or electrochemical measurement.

  The TOF-SIMS measurement may be a measurement in the depth direction using mass spectrometry, element mapping measurement, secondary ion microscope observation, or three-dimensional mapping.

  The sample holder further includes a reference electrode, a holding mechanism capable of measuring the cross-sectional structure of the LIB, or a holding mechanism capable of measuring a laminated structure using three-dimensional mapping by fixing the sample by rotating 90 degrees. It may be what has.

  The material of the sample holder may be a stainless steel material, a battery electrode material that chemically reacts at the interface with the sample and operates as a battery, a piezoelectric material, or a magnetic material.

  The sample may be an all-solid-type LIB, a battery material using a partially ionic liquid, or a half battery using a partially ionic liquid.

  Further, the two electrodes may be a working electrode and a counter electrode.

  In addition, the current voltage application source of the current voltage application measurement mechanism in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) may be a potentio galvanostat. This current / voltage application source measures the charge / discharge characteristics of LIB, the time-of-flight secondary ion mass spectrometer (TOF-SIMS) measures Li element mapping, the material of the sample holder is stainless steel, The LIB is configured to measure a cross-sectional structure, and the sample may be an all-solid-type LIB.

  According to the current voltage application measurement mechanism in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to the present invention, a lithium ion battery (LIB) sample in which movement of internal ions occurs due to application of current / voltage is very high. Current and voltage application tests can be performed inside the TOF-SIMS measurement chamber (in an inert atmosphere) kept in a vacuum, and the results of LIB electrochemical measurement tests and changes in elemental analysis mapping can be performed without exposing the LIB samples to the atmosphere. It is possible to make a one-to-one correspondence, and therefore it is possible to perform an accurate measurement with a simple configuration.

It is the schematic which shows operation | movement of the conventional time-of-flight type secondary ion mass spectrometer (TOF-SIMS). It is the schematic which shows the operation | movement of the electrochemical measurement of the conventional LIB. It is the schematic which shows operation | movement of the time-of-flight type secondary ion mass spectrometer (TOF-SIMS) concerning this invention. It is the schematic which shows the structure of the switch mechanism used inside the apparatus concerning this invention. It is a time chart which shows an example of operation | movement control of the time-of-flight type secondary ion mass spectrometer by the switch mechanism used inside the apparatus concerning this invention. In the apparatus concerning this invention, it is the schematic which shows the structure of the sample holder of a solid sample. It is a graph which shows an example of the charging / discharging characteristic of LIB measured by the apparatus concerning this invention. It is a figure which shows the state of the positive electrode vicinity of the battery in the characteristic shown by FIG. It is a figure which shows the state of the positive electrode vicinity of the battery in the characteristic shown by FIG. It is a figure which shows the state of the positive electrode vicinity of the battery in the characteristic shown by FIG. It is a figure which shows the state of the positive electrode vicinity of the battery in the characteristic shown by FIG. It is a perspective view which shows another form of holding | maintenance of the sample by a sample holder. It is a figure which shows the example of a connection in case the fixing member of a sample holder does not have electroconductivity.

  FIG. 2 is a schematic view showing an embodiment of a time-of-flight secondary ion mass spectrometer (TOF-SIMS) used for the current voltage application measurement mechanism in the time-of-flight secondary ion mass spectrometer according to the present invention. .

  In this figure, as in FIG. 1, a solid sample 20 such as an all-solid-state LIB corresponds to a pair in the measurement chamber 1 of a time-of-flight secondary ion mass spectrometer (TOF-SIMS). It is sandwiched between conductive fixing members 10A and 10B. As in the case of FIG. 1, the primary ions collide with the fixed sample 20, the secondary ions are generated by the sputtering phenomenon, and the ions are blown in one direction by the electric field, based on the speed determined by the mass of the scattered secondary ions. The time to a predetermined distance is detected, and finally the mass of the secondary ion is calculated. This enables mass spectrometry. The sample is not limited to the all-solid-state LIB, but may be a battery material using a part of ionic liquid, a half battery using a part of ionic liquid, or the like.

  Here, a high voltage power supply HV40 for supplying a voltage of about 3 kV required for mass spectrometry is connected to the positive electrode of the LIB via a switch 30A. Further, an ammeter 50 for measuring a current during the mass spectrometry operation is connected to the negative electrode of the LIB through a switch 30B. 30A and 30B are often used in conjunction.

  These switches 30A and 30B are housed in the switch box 3 together with switches 30C and 30D for current / voltage characteristic measuring equipment described later, or are controlled by wiring from the switch box 3 or remote operation such as wireless. The If there is little need to measure current when performing mass spectrometry, the ammeter 50 may not be provided. Since the switches 30A and 30B are operated at a high voltage, it may be desirable to arrange them in a vacuum. In that case, as shown in FIG. 2, the main bodies of the switches 30 </ b> A and 30 </ b> B may be disposed inside the measurement chamber 1. However, if there is little need for such an arrangement, these switches can be provided outside the measurement chamber 1 together with 30C and 30D. That is, the arrangement of the switches 30A, 30B, 30C, and 30D can be arbitrarily set either inside or outside the measurement chamber 1 in consideration of technical necessity and arrangement location.

  A current / voltage measuring device 2 for measuring the electrical characteristics of the solid sample 20 is disposed outside the measurement chamber 1. For example, a potentiostat or a potentio galvanostat can be used. When controlling only the voltage, a potentiostat may be used. However, since the voltage and current are normally controlled by combining both modes, a potentio galvanostat is used.

  In the embodiment shown in FIG. 2, a pair of opposing conductive fixing members 10A and 10B are respectively connected to a counter electrode 21A and a working electrode of a potentio galvanostat through a pair of switches 30C and 30D in the switch box 3. 21B is connected. In FIG. 2, the solid sample 20 operates as a battery in which the fixing member 10B is a positive electrode and the fixing member 10A is a negative electrode, and its electrical characteristics are measured by a potentio galvanostat. The switches 30C and 30D can be configured to open and close in conjunction with the switches 30A and 30B. As will be described later, when performing mass spectrometry, the switches 30C and 30D are turned off, and on the contrary, the switches 30A and 30D are turned on, and a voltage is applied by the high voltage power supply HV40. In addition, the potentio galvanostat as the current / voltage measuring device 2 and the switch box 3 can be configured as an integrated unit and disposed outside the measuring chamber 1.

  In the potentio galvanostat as the current-voltage measuring device 2, the current measuring and current measuring terminals WE1 and WE2 operate as working electrodes, and the current measuring terminal CE operates as a counter electrode. WE indicates a Working Electrode, and CE indicates a Counter Electrode. These respective electrodes are connected to the negative electrode and the positive electrode of the solid sample 20, respectively. In addition, when using a potentio galvanostat, you may provide a reference electrode (RE: Reference Electrode) in addition to these working electrodes and counter electrodes.

  FIG. 3A is a schematic diagram for explaining a control circuit 300 provided in the switch box 3 for controlling the switches 30A, 30B, 30C and 30D. A high voltage of about 3 kV is applied to the solid sample 20 when mass spectrometry is performed, but this high voltage needs to be turned off when measurement using a potentio galvanostat is performed. That is, if a voltage is applied at the same time, the potentio galvanostat is damaged by the high voltage. Therefore, as shown in FIG. 2, when the switches 30A and 30B are turned on, 30C and 30D are turned off. Conversely, when the switches 30A and 30B are turned off, the control circuit 300 is turned on. Provide. This control circuit may be configured to switch mechanical contacts, or may be configured as a switching circuit using a transistor, an FET, or the like.

  FIG. 3B shows an example of the control of the time-of-flight ion mass spectrometer according to the present invention by the operation of the switches 30A, 30B, 30C and 30D configured as described above and controlled by the control circuit 300. It is a time chart shown along the time axis t. In this example, the solid element 20 is connected to a potentio galvanostat, and the case where the Li element mapping is acquired before and after measuring the charge / discharge characteristics is shown.

  FIG. 4 is a schematic diagram illustrating an example of how the solid sample 20 is sandwiched between the pair of conductive fixing plates 10A and 10B. In the embodiment shown in this figure, the positive electrode and the negative electrode of a battery material such as LIB are held in contact with the surfaces of the conductive fixing plates 10A and 10B. Both fixing plates 10A and 10B are connected and fixed by screws 60 inserted into through holes 70A and 70B provided in the respective fixing plates 10A and 10B. The inner surface of the through hole 70B is female threaded. An insulating sheet 90 is provided between the fixing plate 10 </ b> B and the screw 60. In this way, the sample holder is constituted by the pair of conductive fixing plates 10A and 10B. The method of clamping and fixing the fixed sample 20 is not limited to this method. In addition, in FIG. 4, only one screw fixing structure is used, but it is also possible to fix at a plurality of locations as necessary. .

  FIG. 5 is a graph showing the results of measuring the charge / discharge characteristics of an all-solid-state LIB using the thus-configured time-of-flight ion mass spectrometer, which is an embodiment of the present invention. FIG. 6D is a diagram showing Li element mapping in a portion corresponding to (a) to (d) in FIG. 5. The lower part of each figure shows the vacuum part outside the solid sample, the positive electrode of the solid sample, and the electrolyte part inside the LIB. In this way, the process of charge / discharge characteristics is associated with the Li element mapping. That is, TOF-SIMS measurement with a time-of-flight secondary ion mass spectrometer (TOF-SIMS) and measurement of electrical characteristics by applying a current voltage to the solid sample are brought together into the atmosphere. It can carry out continuously in the vacuum which is an inert atmosphere, without opening.

  Note that the measurement of electrical characteristics such as the charge / discharge characteristics of LIB is not limited to charge / discharge, and impedance measurement or electrochemical measurement of a solid sample can be performed. In addition, the TOF-SIMS measurement is not limited to mass spectrometry or element mapping, but can be observed in a secondary ion microscope or in the depth direction using three-dimensional mapping.

  Furthermore, the material of the fixing members 10A and 10B constituting the sample holder is not limited to stainless steel, and conductive materials can be used. Battery electrode materials that perform battery reaction by chemical reaction at the interface with the solid sample, and piezoelectric materials can be used. A material material, a magnetic material material, etc. can be used. The fixing member is not limited to a conductive member, and is simply configured to sandwich the solid sample 20. As shown in FIG. 8, the electrode of the solid sample 20 is connected to the counter electrode and the action of the current-voltage characteristic measuring instrument. You may comprise so that a pole may be directly connected.

  In the embodiment shown in FIG. 2, the solid sample is held so that the cross-sectional structure of the LIB can be measured. However, the present invention is not limited to such a form, and the solid sample is rotated 90 degrees as shown in FIG. It is also possible to measure the layered structure of the solid sample.

  As described above, according to the mass spectrometer according to the present invention, a conventional time-of-flight ion mass spectrometer is used, and the TOF-SIMS measurement and the potentio Measurement of the electrical characteristics of the sample using a current-voltage measuring device such as a galvanostat can be performed collectively.

  The embodiments disclosed in this specification are for the purpose of explaining, not limiting the present invention, and the spirit and scope of the present invention are not limited by such embodiments. The scope of the present invention should be construed according to the claims, and all technologies within the equivalent scope should be construed as being included in the scope of the present invention.

1: Chamber, 10A, 10B: Fixed member, 20: Solid sample, 2: Current / voltage measuring device, 3: Switch box, 30A-30D: Switch, 21A: Counter electrode, 21B: Working electrode, 40: High voltage power supply HV, 50 : Ammeter, 60: Screw, 70A / 70B: Through hole, 90: Insulating plate

Claims (22)

A time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism,
A sample holder having at least two electrodes and a fixing member for fixing the sample, and a current-voltage measuring device for performing a current-voltage application test,
The sample holder is configured to hold the sample,
The TOF-SIMS measurement by the TOF-SIMS, the application of the current voltage to the sample by the current-voltage measuring instrument, and the measurement of the electrical characteristics accompanying the application of the sample are configured to be performed collectively. Time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism.   2. The current voltage application measurement mechanism in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to claim 1, wherein the current voltage application test is a LIB charge / discharge characteristic measurement.   The current voltage application measurement mechanism in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to claim 1 or 2, wherein the current voltage application test is impedance measurement.   The current voltage application test mechanism in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to any one of claims 1 to 3, wherein the current voltage application test is an electrochemical measurement.   The said time-of-flight secondary ion mass spectrometer (TOF-SIMS) internal current voltage application measurement mechanism according to any one of claims 1 to 4, wherein the TOF-SIMS measurement is mass spectrometry.   The said time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism according to any one of claims 1 to 5, wherein the TOF-SIMS measurement is an elemental mapping measurement. .   The said time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement according to any one of claims 1 to 6, wherein the TOF-SIMS measurement is observation with a secondary ion microscope. mechanism.   The time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to any one of claims 1 to 5, wherein the TOF-SIMS measurement is a measurement in a depth direction using three-dimensional mapping. ) Internal current voltage application measurement mechanism.   The time-of-flight secondary ion mass spectrometer (TOF-SIMS) internal current voltage application measurement mechanism according to any one of claims 1 to 8, wherein the sample holder further includes a reference electrode.   The material for the fixing member is a current voltage application measurement mechanism in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to any one of claims 1 to 9, wherein the material of the fixing member is a stainless material.   11. The time-of-flight secondary ion according to claim 1, wherein the material of the fixing member is made of a battery electrode material that chemically reacts with an interface with the sample and operates as a battery. Current voltage application measurement mechanism in a mass spectrometer (TOF-SIMS).   10. The time-of-flight secondary ion mass spectrometer (TOF-SIMS) internal current voltage application measurement mechanism according to any one of claims 1 to 9, wherein a material of the fixing member is a piezoelectric material.   The time-of-flight secondary ion mass spectrometer (TOF-SIMS) internal current voltage application measurement mechanism according to any one of claims 1 to 12, wherein the material of the fixing member is a magnetic material.   The current in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to any one of claims 1 to 13, wherein the sample holder has a holding mechanism capable of measuring a LIB cross-sectional structure. Voltage application measurement mechanism.   The sample holder includes a holding mechanism capable of measuring a laminated structure using three-dimensional mapping by rotating and fixing the sample by 90 degrees. Time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism.   The time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism according to any one of claims 1 to 15, wherein the sample is an all-solid-type LIB.   The current voltage application in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to any one of claims 1 to 16, wherein the sample is a battery material using a partially ionic liquid. Measuring mechanism.   The current voltage application in the time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to any one of claims 1 to 16, wherein the sample is a half cell using a partial ionic liquid. Measuring mechanism. 19. The time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism according to any one of claims 1 to 18, wherein the two electrodes are a working electrode and a counter electrode.   The current-voltage measuring instrument measures the charge / discharge characteristics of LIB, the time-of-flight secondary ion mass spectrometer (TOF-SIMS) measures Li element mapping, and the material of the sample holder is stainless steel, 2. The time-of-flight secondary ion mass spectrometer (TOF-SIMS) according to claim 1, wherein the sample holder is configured to measure a cross-sectional structure of a LIB, and the sample is an all-solid-type LIB. Current voltage application measurement mechanism.   The application of the voltage for the TOF-SIMS measurement by the TOF-SIMS performed collectively and the application of the current voltage to the sample by the current-voltage measuring device are switched by a switch. The time-of-flight secondary ion mass spectrometer (TOF-SIMS) current voltage application measurement mechanism.   The said voltage measurement apparatus is a potentio galvanostat, The current voltage application measurement mechanism in the said time-of-flight type secondary ion mass spectrometer (TOF-SIMS) as described in any one of Claim 1 to 21 .