JP2016170093A - Sample holder and x-ray analysis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a proper electrical connection state between a positive electrode and a negative electrode in X-ray analysis for a laminate cell even when a gas is generated in the laminate cell.SOLUTION: A sample holder 21 is used for in-situ X-ray analysis which obtains analytical data of a battery element such as a lithium ion secondary battery by irradiating, as a sample, a thin plate-like laminate cell 10 hermetically sealed with electrolyte by a laminate film with an X-ray. The sample holder comprises: a pair of supporting members 22a, 22b holding and supporting the laminate cell 10 from both sides; and means 24 for pressing the pair of supporting members so as not to be separated from each other. Each of the pair of supporting members includes: supporting surfaces 25a, 25b arranged opposite a principal surface of the laminate cell; and X-ray transparent holes 26a, 26b for transmitting an X-ray therethrough. The size of the X-ray transparent hole 26b increases as away from the supporting surface 25b.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sample holder for X-ray analysis suitable for measuring an electronic state and a structural change of a secondary battery in a charge / discharge process, and an X-ray analysis method using the same.

  Among secondary batteries, a lithium ion secondary battery is known as a battery having a high energy density and a high operating voltage. For this reason, lithium ion secondary batteries are widely used in portable electronic devices such as mobile phones and notebook personal computers, as well as power sources for hybrid vehicles and electric vehicles.

  Generally, a lithium ion secondary battery is composed of a positive electrode having a positive electrode active material as a main component, a negative electrode having a negative electrode active material as a main component, a separator separating the positive electrode and the negative electrode, a non-aqueous electrolyte, and the like. Yes. These constituent materials are sealed with an exterior material such as a metal can or an aluminum laminate film. Those using metal cans as exterior materials are called hard pack types, and those using aluminum laminate films are also called soft pack types or laminate cells.

  In the development of battery materials, X-ray analysis is employed to evaluate battery materials. X-ray analysis, particularly X-ray diffraction (hereinafter referred to as XRD) measurement, is an analytical method that provides information such as crystal structure, valence of each constituent element and local structure (coordination number, interatomic distance). It is widely used for the evaluation of battery materials.

  The X-ray analysis methods for battery materials are roughly classified into ex-situ measurement and in-situ measurement. In ex-situ measurement, charged and discharged battery cells are disassembled, and constituent materials such as positive electrodes are taken out and subjected to X-ray analysis. In-situ measurement is to perform X-ray analysis while charging and discharging without disassembling the battery. In the case of a secondary battery using a non-aqueous electrolyte such as a lithium ion secondary battery, in the ex-situ measurement, if the constituent material such as the positive electrode is taken out from the battery outer packaging material and exposed to the atmosphere, the positive electrode activity in the positive electrode is The state of the substance may change. For this reason, in-situ measurement capable of evaluating a state close to an actual battery reaction is becoming mainstream in recent years.

  Regarding in-situ X-ray analysis, as described in Non-Patent Document 1, for example, a special electrochemical cell for X-ray analysis using metal beryllium has been developed and used for evaluation of battery materials. ing. Metal beryllium is conductive and has a high X-ray transmittance, so it is used as a material for a window portion that transmits X-rays. However, when metal beryllium is used as the material for the window, (1) it is difficult to handle because the oxide of beryllium is a poison, and (2) the cell fabrication cost is high due to the complicated structure of the electrochemical cell. There was a problem such as.

  On the other hand, as described in Patent Document 1, a method of directly performing X-ray analysis for a thin plate battery (laminate cell) covered with an aluminum laminate film or the like is also employed. The laminate cell has a high X-ray transmittance because the positive electrode, the negative electrode, and the exterior are sufficiently thin. For this reason, X-ray analysis can be carried out as it is without disassembling the laminate cell. This method has an advantage that a plurality of cells can be easily manufactured because the handling of the laminate cell is simple and the manufacturing cost of the cell is low.

JP-A-11-230919

M. N. Richard et al, J. Electrochem. Soc. 144, 554, (1997)

  However, in the past, in the in-situ X-ray analysis, the laminate cell was simply placed on the sample stage and allowed to transmit X-rays, so the following problems might occur depending on the measurement conditions. . That is, when the performance of a secondary battery is evaluated by in-situ X-ray analysis using a laminate cell that is thin and easy to change in shape, for example, charging and discharging at a high voltage of about 4.8 V, for example. If the process is repeated, charging and discharging may not be performed properly during the measurement.

  Then, this inventor tried to confirm the state of the laminate cell which became unable to charge / discharge appropriately in the middle of a measurement. As a result, I noticed that the laminate cell was slightly swollen overall before the measurement. From this fact, when the present inventor performs charge / discharge in a high voltage region, gas is generated in the laminate cell due to decomposition of the electrolytic solution, release of oxygen from the positive electrode active material, and the like. It was thought that the laminate cell swelled due to an increase in the pressure in the battery, and as a result, the relative positional relationship between the positive electrode and the negative electrode changed. That is, in the in-situ X-ray analysis for the laminate cell, the present inventor is unable to charge / discharge properly during the measurement because the positive electrode and the negative electrode adjacent to each other with the separator interposed therebetween. The present invention was conceived on the basis of the idea that the gas was separated as the gas was generated and the electrical connection state thereof deteriorated.

  The main object of the present invention is to maintain a good electrical connection between the positive electrode and the negative electrode even in the case where gas is generated in the laminate cell in the X-ray analysis for the laminate cell. An object of the present invention is to provide a sample holder and an X-ray analysis method for X-ray analysis that enable X-ray analysis.

The first aspect of the present invention is:
A battery element formed by laminating a positive electrode and a negative electrode with a separator in between is used as a sample of a thin plate-like laminate cell sealed with a laminate film together with an electrolytic solution, and X-rays are applied to the laminate cell to obtain analysis data A sample holder for use in situ X-ray analysis,
A pair of support members that sandwich and support the laminate cell from both sides;
Pressing means for pressing the pair of support members so that the pair of support members are not separated from each other,
Each of the pair of support members has a support surface disposed so as to face the main surface of the laminate cell, and an X-ray transmission hole that transmits the X-rays,
The sample holder is characterized in that the size of the X-ray transmitting hole formed in at least one of the pair of support members increases as the distance from the support surface increases.

The second aspect of the present invention is:
A battery element formed by laminating a positive electrode and a negative electrode with a separator in between is used as a sample of a thin plate-like laminate cell sealed with a laminate film together with an electrolytic solution, and X-rays are applied to the laminate cell to obtain analysis data -In situ X-ray analysis,
The laminate cell is supported by being sandwiched by a pair of support members from both sides, and the pair of support members are pressed so that the pair of support members are not separated from each other, and X-ray transmitting holes are respectively formed in the pair of support members. Forming and expanding the size of the X-ray transmitting hole formed in at least one of the pair of support members as the distance from the laminate cell increases. The X-ray analysis method is characterized in that X-ray analysis of the laminate cell is performed while avoiding interference.

  According to the present invention, in X-ray analysis for a laminate cell, even when gas is generated in the laminate cell, the electrical connection state between the positive electrode and the negative electrode can be favorably maintained. For this reason, it becomes possible to realize highly reliable X-ray analysis. According to the present invention, interference between the X-ray diffracted in the laminate cell and the support member can be avoided.

It is the schematic which shows an example of a structure of a X-ray analyzer. It is a schematic sectional drawing which shows the structure of the lamination cell used as an example of the target sample of X-ray analysis. It is sectional drawing which shows an example of a structure of the sample holder which concerns on embodiment of this invention. The structure of the supporting member 22a is shown, (A) is a front view in the figure, (B) is JJ sectional drawing of (A). It is a perspective view which shows the structure of the supporting member 22a. The structure of the support member 22b is shown, (A) is a front view in the figure, (B) is KK sectional drawing of (A). It is a perspective view which shows the structure of the supporting member 22b. It is a figure which shows the pressing location of a pressing means, (A) has shown the pressing location in one support member, and (B) has shown the pressing location in the other support member in the figure. It is a figure which shows the structural example of a 1st pressing means. It is a figure which shows the structural example of a 2nd pressing means. It is a schematic sectional drawing which shows a 1st modification. It is a schematic sectional drawing which shows a 2nd modification. It is a perspective view which shows a 2nd modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, in order to solve the above-mentioned problems, the present inventor proposes an invention relating to a sample holder including a pair of support members that sandwich and support a laminate cell from both sides and an X-ray analysis method using the sample holder. Proposed by However, in the prior invention, when X-ray diffraction measurement is performed, X-rays diffracted in the laminate cell sometimes interfere with the support member. Therefore, the present inventor has improved the invention of the prior application.
In the embodiment of the present invention, description will be given in the following order.
1. 1. Configuration of X-ray analyzer 2. Laminate cell configuration Configuration of sample holder 4. 4. X-ray analysis method Effects of the embodiment 6. Modifications etc.

<1. Configuration of X-ray analyzer>
FIG. 1 is a schematic diagram showing an example of the configuration of an X-ray analyzer.
First, in the X-ray analysis, X-rays generated from a laboratory X-ray apparatus or a synchrotron radiation facility can be used for the X-ray source 1. A sample stage 2 and an X-ray detector 4 are sequentially arranged in the X-ray emission direction of the X-ray source 1. The sample stage 2 is a part where a sample 3 to be subjected to X-ray analysis is set. In this embodiment, as an example, a laminate cell, which will be described later, is a sample 3. The X-ray detector 4 detects the intensity of the X-ray incident on the sample 3 and diffracted by the sample 3. In FIG. 1, X-rays incident on the sample 3 are expressed as “incident X-rays”, and X-rays diffracted by the sample 3 are expressed as “diffracted X-rays”. The X-ray detector 4 can be moved around the sample 3 in the arrow direction (sweep direction) in the figure by a moving mechanism (not shown). “2θ” in the figure indicates the X-ray diffraction angle.

  In the X-ray analyzer configured as described above, after setting the sample 3 on the sample stage 2 and emitting X-rays from the X-ray source 1, the X-rays enter the sample 3. At this time, while the X-ray detector 4 is swept at a constant interval in the direction of the arrow in the figure, X-rays transmitted through the sample 3 and diffracted are taken into the X-ray detector 4 and the intensity of the X-ray is measured. Thereby, the X-ray diffraction profile of the sample 3 can be obtained. The X-ray diffraction profile is represented by a grab with the X-ray intensity on the vertical axis and the X-ray diffraction angle (2θ) on the horizontal axis.

<2. Laminate cell configuration>
FIG. 2 is a schematic cross-sectional view showing a configuration of a laminate cell as an example of a target sample for X-ray analysis. The illustrated laminate cell 10 includes a battery element 14 including a positive electrode 11, a negative electrode 12, and a separator 13. The positive electrode 11 is formed in a rectangular sheet shape in front view (plan view). A positive electrode active material layer 15 is formed on one surface of the positive electrode 11. The positive electrode active material layer 15 is formed with a coating film using, for example, lithium nickelate, a conductive additive, and a binder. The negative electrode 12 is formed in a rectangular sheet shape when viewed from the front. A negative electrode active material layer 16 is formed on one surface of the negative electrode 12. The negative electrode active material layer 16 is formed with a coating film using, for example, graphite and a binder. The separator 13 is formed in a rectangular sheet shape when viewed from the front. The battery element 14 has a structure in which the positive electrode 11 and the negative electrode 12 are stacked with the separator 13 interposed therebetween. In this laminated structure, the positive electrode active material layer 15 of the positive electrode 11 and the negative electrode active material layer 16 of the negative electrode 12 are disposed so as to face each other with the separator 13 therebetween.

  The battery element 14 is sealed with a laminate film 17 together with an electrolyte solution (not shown). However, a terminal (not shown) connected to the positive electrode 11 and a terminal (not shown) connected to the negative electrode 12 are drawn out to the outside of the laminate film 17 in order to connect terminals for charging / discharging (not shown). The laminate film 17 is formed in a rectangular bag shape when viewed from the front. An appropriate amount of electrolytic solution made of a non-aqueous electrolytic solution is injected into the laminate film 17. Thus, the laminate cell 10 constitutes a laminate sheet type lithium ion secondary battery. In addition, the laminate cell 10 has a thin plate structure in which the positive electrode 11, the negative electrode 12, and the separator 13 are each formed of a single sheet so that as much X-rays as possible can be transmitted when performing X-ray analysis. .

<3. Configuration of sample holder>
3 is a cross-sectional view showing an example of the configuration of the sample holder according to the embodiment of the present invention.
The illustrated sample holder 21 is used when performing X-ray analysis using the above-described laminate cell 10 as a sample. The “X-ray analysis” described here refers to in-situ X-ray analysis in which X-rays are incident on the laminate cell 10 to obtain analysis data. Further, “in-situ X-ray analysis” refers to performing X-ray analysis without disassembling the laminate cell 10 constituting the lithium ion secondary battery.

  The sample holder 21 generally includes a pair of support members 22a and 22b, a pair of window members 23a and 23b, and a pressing unit 24.

(Support member)
The pair of support members 22a and 22b support the laminate cell 10 that is a sample for X-ray analysis from both sides. The pair of support members 22a and 22b are arranged separately on the X-ray incident side (right side in FIG. 3) and the X-ray transmission side (left side in FIG. 3) with the laminate cell 10 as the center. That is, one support member 22a is disposed on the X-ray incident side, and the other support member 22b is disposed on the X-ray transmission side. The X-ray incident side refers to the side on which X-rays are incident on the laminate cell 10, and the X-ray transmission side refers to the side on which X-rays are transmitted from the laminate cell 10. In the case of FIG. 1 above, the side on which the X-ray source 1 is arranged (left side in FIG. 1) is the X-ray incident side, and the opposite side (right side in FIG. 1) is based on the position of the sample 3. X-ray transmission side.

  Each support member 22a, 22b is formed using the same material. One main surface of the support member 22 a is a support surface 25 a that holds the laminate cell 10. Similarly, one main surface of the support member 22 b is a support surface 25 b that holds the laminate cell 10. The pair of support members 22a and 22b are arranged so that the support surfaces 25a and 25b face each other. For this reason, when the laminate cell 10 is disposed between the pair of support members 22a and 22b, the support surface 25a of one support member 22a faces one main surface of the laminate cell 10 and the other support member. The support surface 25b of 22b is arrange | positioned so that the other main surface of the lamination cell 10 may be opposed.

  Each of the support members 22a and 22b is made of a material having mechanically high rigidity, electrical insulation, and optically high light transmittance. The “high rigidity” described here is a rigidity that does not yield and deform due to the pressure associated with the generation of gas in the laminate cell 10 when the laminate cell 10 is supported by a pair of support members 22a and 22b. Say. Further, “high light transmission” refers to light transmission enough to visually confirm an object existing on the other side when viewed through the other of the supporting members 22a and 22b in the thickness direction. As a constituent material of the supporting members 22a and 22b satisfying the above properties, for example, an acrylic resin can be cited.

4A and 4B show the structure of the support member 22a. FIG. 4A is a front view, and FIG. 4B is a sectional view taken along line JJ in FIG. FIG. 5 is a perspective view showing the structure of the support member 22a.
As illustrated, the support member 22a is formed in a plate shape having a rectangular shape when viewed from the front. The support member 22a is provided with an X-ray transmission hole 26a. The X-ray transmission hole 26a is provided in the support member 22a as an X-ray transmission part that transmits X-rays. One X-ray transmission hole 26a is formed at the center of the support member 22a so as to penetrate the support member 22a in the thickness direction (plate thickness direction). The X-ray transmission hole 26a is formed in a circular shape when viewed from the front. The X-ray transmission hole 26a is formed with the same diameter (hole diameter) φ1 over the entire thickness direction of the support member 22a.

  The support member 22a is provided with four connection holes 27a. The connection hole 27a is provided to connect the pair of support members 22a and 22b to each other. The connection holes 27a are provided one by one at the four corners of the support member 22a so as to penetrate the support member 22a in the thickness direction.

6A and 6B show the structure of the support member 22b, in which FIG. 6A is a front view, and FIG. 6B is a sectional view taken along line KK in FIG. FIG. 7 is a perspective view showing the structure of the support member 22b.
As shown in the figure, the support member 22b is formed in a plate shape having a rectangular shape when viewed from the front, for example, with the same external dimensions and thickness dimensions as the support member 22a described above. The support member 22b is provided with an X-ray transmission hole 26b. The X-ray transmission hole 26b is provided in the support member 22b as an X-ray transmission part that transmits X-rays. One X-ray transmission hole 26b is formed at the center of the support member 22b so as to penetrate the support member 22b in the thickness direction. The X-ray transmission hole 26b is formed in a circular shape when viewed from the front.

  Further, unlike the X-ray transmission hole 26a described above, the X-ray transmission hole 26b has a shape in which the size of the hole is gradually enlarged. Specifically, the size of the X-ray transmission hole 26b is formed in a truncated cone shape so as to gradually increase as the distance from the support surface 25b increases in the thickness direction of the support member 22b. The inner surface of the X-ray transmission hole 26b has a tapered shape that is uniformly inclined over the entire thickness direction of the support member 22b. In the present embodiment, since the X-ray transmission hole 26b is formed in a circular shape when viewed from the front, the size of the X-ray transmission hole 26b can be defined by the diameter. The diameter of the X-ray transmitting hole 26b has a minimum diameter φ2 at the opening edge of the support surface 25b, which is one main surface of the support member 22b, and a maximum diameter φ3 at the opening edge of the main surface on the opposite side. ing. As a result, the size of the X-ray transmission hole 26b gradually increases from the X-ray incident side toward the X-ray transmission side. The minimum diameter φ2 of the X-ray transmission hole 26b is set larger than the diameter φ1 of the X-ray transmission hole 26a described above. The opening angle of the X-ray transmission hole 26b with respect to the central axis can be defined by the thickness dimension of the support member 22b and the minimum diameter φ2 and the maximum diameter φ3 of the X-ray transmission hole 26b. Specifically, the degree of the opening angle of the X-ray transmission hole 26b may be appropriately set according to the range of the diffraction angle of the X-ray to be measured by the X-ray detector 4.

  The support member 22b is provided with four connection holes 27b, similar to the support member 22a described above. The positional relationship between the four connecting holes 27b is the same as the positional relationship between the four connecting holes 27a described above. The connection hole 27b is provided to connect the pair of support members 22a and 22b to each other. The connection holes 27b are provided one by one at the four corners of the support member 22b so as to penetrate the support member 22b in the thickness direction.

(Window member)
The pair of window members 23a and 23b are in direct contact with the laminate cell 10 when the laminate cell 10 is sandwiched between the pair of support members 22a and 22b described above. Each of the window members 23a and 23b is formed in the same shape and size using the same material. More specifically, the window members 23a and 23b are formed in a sheet shape having a rectangular shape in plan view, which is thinner than the support members 22a and 22b and smaller in width (shorter dimension) than the support members 22a and 22b. The window members 23a and 23b are made of a material having both predetermined X-ray transmittance and rigidity. As a material of the window members 23a and 23b, it is preferable to use carbon fiber reinforced plastic for the reason described later.

  The pair of window members 23a and 23b are attached to the support surfaces 25a and 25b of the corresponding support members 22a and 22b. That is, one window member 23a is attached to the support surface 25a of the support member 22a arranged on the X-ray incident side, and the other window member 23b is a support surface of the support member 22b arranged on the X-ray transmission side. It is affixed to 25b. Thereby, one end of the X-ray transmission hole 26a of the support member 22a is closed by the window member 23a, and one end of the X-ray transmission hole 26b of the support member 22b is closed by the window member 23b. When the laminate cell 10 is disposed between the pair of support members 22a and 2b, the window member 23a attached to one support member 22a faces one main surface of the laminate cell 10, and the other The window member 23b attached to the support member 22b is disposed so as to face the other main surface of the laminate cell 10.

Here, a dimension example of the laminate cell 10 and a corresponding dimension example of the support members 22a and 22b and the window members 23a and 23b will be described.
The dimensions of the laminate cell 10 are, for example, long dimension = 80 mm, short dimension = 60 mm, and thickness dimension = 1 mm, excluding the portion of the terminal T connected to the positive electrode and the negative electrode. In such a case, assuming that the support members 22a and 22b are made of an acrylic plate, the dimensions of each part of the support members 22a and 22b are set to, for example, the longitudinal dimension = 100 mm, the short dimension = 50 mm, and the thickness dimension = 10 mm. be able to. The X-ray transmitting holes 26a and 26b are, for example, X 2 X scan (a method in which X-rays are irradiated perpendicularly to the laminate cell 10 as a sample and only the X-ray detector 4 is swept). The support member 22a on the line incident side is provided with an X-ray transmission hole 26a having a uniform diameter (φ1) = 5 mm, and the minimum diameter (φ2) = 10 mm and the maximum diameter is provided on the support member 22b on the X-ray transmission side. By providing the X-ray transmitting hole 26b with (φ3) = 45 mm, it becomes possible to measure in the range of diffraction angle (2θ) = 0 to 60 degrees. If the window members 23a and 23b are made of carbon fiber reinforced plastic film, the dimensions of each part of the window members 23a and 23b are, for example, a longitudinal dimension = 80 mm, a short dimension = 20 mm, and a thickness dimension = 0.2 mm. Can be set to

(Pressing means)
The pressing means 24 presses the pair of support members 22a and 22b so that the pair of support members 22a and 22b are not separated when the laminate cell 10 is supported between the pair of support members 22a and 22b. . The holding means 24 has a pair of support members 22a, 22a, 22b at positions other than the portions where the X-ray transmission holes 26a, 26b are formed so as not to interfere with the X-rays passing through the X-ray transmission holes 26a, 26b of the support members 22a, 22b. Hold 22b. Here, the structure which hold | suppresses a pair of support member 22a, 22b in a total of six places as an example is demonstrated.

  As shown in FIGS. 8A and 8B, the pressing means 24 includes a first pressing means for pressing the four corners (P1, P2, P3, P4) of the support members 22a and 22b, and the first pressing means. And a second pressing means for pressing the portions (P5, P6) closer to the X-ray transmitting holes 26a, 26b.

  The first pressing means presses the pair of support members 22a, 22b by connecting the pair of support members 22a, 22b at the four corners P1, P2, P3, P4 of the support members 22a, 22b, respectively. For example, as shown in FIG. 9, the first pressing means uses a screw 30 inserted into the connection holes 27 a and 27 b formed in the support members 22 a and 22 b and a nut 31 screwed into the screw 30. Can be configured. In this configuration, by tightening the nut 31 that is screwed onto the screw 30, the pair of support members 22a and 22b can be pressed so as to be coupled (connected) to each other.

  The second pressing means presses the pair of support members 22a and 22b toward each other at two locations P5 and P6 in the vicinity of the X-ray transmission holes 26a and 26b of the support members 22a and 22b. The supporting members 22a and 22b are pressed. For example, as shown in FIG. 10, the second pressing means can be configured using a fastening tool having a pair of pressors 32 a and 32 b. Two locations P5 and P6 in the vicinity of the X-ray transmission holes 26a and 26b are set at positions that are spaced apart from each other by an equal distance from the support members 22a and 22b with the X-ray transmission holes 26a and 26b as the center. ing. The fastening tool is made of metal, for example. The pair of pressurizers 32a and 32b can be moved in directions toward or away from each other, for example, by rotating a screw-type operation rod included in the fastening tool. In this configuration, the operating rod of the fastening tool is appropriately rotated to bring the pair of pressurizers 32a and 32b into contact with the outer surfaces of the corresponding support members 22a and 22b, and the operating rod is further rotated in this state. By tightening in such a manner, the pair of support members 22a and 22b can be pressed by the pair of pressurizers 32a and 32b.

<4. X-ray analysis method>
Next, an X-ray analysis method using the sample holder according to the embodiment of the present invention will be described. In the present embodiment, as an example of the X-ray analysis method, charging / discharging of the laminate cell 10 is repeatedly performed under predetermined measurement conditions, and X-rays diffracted by the laminate cell 10 while performing this charge / discharge ( A method of obtaining analysis data related to the X-ray diffraction profile of the laminate cell 10 by measuring the intensity of (diffracted X-rays) will be described.

  First, the laminate cell 10 is set in the sample holder 21. At this time, the laminate cell 10 is sandwiched between the pair of support members 22a and 22b so that the pair of window members 23a and 23b are brought into contact with the main surfaces of the corresponding laminate cells 10 respectively. A support member 22a is disposed on the X-ray incident side, and a support member 22b is disposed on the X-ray transmission side. In addition, the positions of the laminate cell 10 and the window members 23a and 23b are aligned so that the opposing surfaces of the pair of window members 23a and 23b cover the main part of the main surface of the corresponding laminate cell 10. At this time, if the support members 22a and 22b are made of a light-transmitting material (typically a transparent material), even when the laminate cell 10 is sandwiched between the pair of support members 22a and 22b, The positional relationship between the laminate cell 10 and the window members 23a and 23b can be grasped from the outside of the support members 22a and 22b.

  Next, the pair of supporting members 22a and 22b are pressed by the first pressing means. Specifically, screws 30 and nuts 31 are respectively attached to the four corners P1, P2, P3, and P4 of the support members 22a and 22b (see FIG. 9). At this time, screws 30 and nuts 31 are attached to the four corners of the respective support members 22a and 22b and temporarily tightened, and then the four nuts 31 are gradually tightened and finally tightened. Thereby, the four corners of the pair of support members 22a and 22b can be tightened with an equal force. Further, the entire laminate cell 10 can be sandwiched between the window members 23a and 23b attached to the support surfaces 25a and 25b of the respective support members 22a and 22b. Note that the tightening force by the nut 31 is at least large enough to prevent the laminate cell 10 sandwiched between the pair of support members 22a and 22b from dropping and not large enough to distort the support members 22a and 22b. .

  Next, the pair of supporting members 22a and 22b are pressed by the second pressing means. Specifically, a pair of pressurizers 32a and 32b are brought into contact with the two places P5 and P6 of each support member 22a and 22b, respectively, and in this state, the operation rod of the tightening tool is rotated and tightened to thereby form a pair of The pair of support members 22a and 22b are sandwiched between the pressurizers 32a and 32b (see FIG. 10). At that time, the pressure members 32a and 32b are brought into contact with the support members 22a and 22b at positions spaced apart from the X-ray transmitting holes 26a and 26b by an equal distance so as to hold the pair of support members 22a and 22b. Further, at each of the locations P5 and P6, the pair of support members 22a and 22b are tightened with an equal force by the pair of pressurizers 32a and 32b corresponding thereto. At this time, marks indicating the places P5 and P6 to be pressed by the pressurizers 32a and 32b are attached to the outer surfaces of the support members 22a and 22b, and the pressurizers 32a and 32b are brought into contact with the positions of the marks. It is good also as a structure.

  When the laminate cell 10 is set in the sample holder 21 in this way, it is placed on the sample stage 2 of the X-ray analyzer and in-situ X-ray analysis is performed. At this time, a terminal for charging / discharging is connected to the terminal T drawn out of the laminate cell 10. And charging / discharging of the lamination cell 10 is repeated on the conditions decided beforehand. Further, X-rays are incident from one side in the thickness direction of the laminate cell 10 to obtain desired analysis data. At that time, the X-rays emitted from the X-ray source 1 pass through the X-ray transmitting hole 26a of the support member 22a disposed on the X-ray incident side, and then enter the laminate cell 10 through the window member 23a. The X-rays that have passed through the laminate cell 10 enter the X-ray transmission hole 26b of the support member 22b disposed on the X-ray transmission side through the window member 23b. In the present embodiment, the size of the X-ray transmission hole 16b increases as the distance from the laminate cell 10 increases. For this reason, the X-ray can be taken into the X-ray detector 4 while avoiding interference between the X-ray diffracted by the laminate cell 10 and the support member 22b. The X-ray detector 4 captures diffracted X-rays at positions corresponding to the respective diffraction angles (2θ) while sweeping at regular intervals in the arrow direction (sweep direction) shown in FIG. To detect. Thereby, analysis data (measurement data) indicating the X-ray diffraction profile of the laminate cell 10 can be obtained.

  According to the analytical data based on such X-ray diffraction measurement, for example, a change in the crystal structure of the positive electrode active material (change in crystal spacing, etc.) accompanying charging / discharging of a lithium ion secondary battery is represented by hexagonal (003 ) The battery material can be evaluated based on the shift to the low angle side of the peak. Incidentally, when X-ray diffraction measurement is performed on the laminate cell 10 constituting the lithium ion secondary battery, a main peak appears in the range of 2θ = 60 degrees or less in the X-ray diffraction profile obtained by this. For this reason, it is considered sufficient to obtain analytical data up to 2θ = 60 degrees by X-ray diffraction measurement in order to appropriately evaluate battery materials.

<5. Effects of the embodiment>
According to the embodiment of the present invention, the following effects can be obtained.
First, when the laminate cell 10 is supported by using the sample holder 21 according to the embodiment of the present invention, and when the laminate cell 10 is simply supported by standing without using the sample holder 21, charge / discharge is repeated. The effect is described from the viewpoint of what kind of difference occurs in the analysis data of the X-ray analysis.

  First, when the laminate cell 10 is simply supported upright, for example, when charging / discharging is repeated at a voltage (for example, 4.8 V) higher than a normal voltage (for example, 4.2 V), There is a possibility that the pressure in the battery rises due to the generated gas and the laminate cell 10 swells. At this time, if the positive electrode 11 and the negative electrode 12 which are adjacent to each other with the separator 13 interposed therebetween are separated as the gas is generated, and their electrical connection state deteriorates, the laminate cell 10 is not properly charged / discharged. . As a result, the analysis data obtained by the X-ray analysis of the laminate cell 10 does not correctly reflect the state of charge / discharge of the laminate cell 10, and it becomes impossible to perform highly reliable X-ray analysis. Further, when the laminate cell 10 swells due to the generation of the gas, the position of the cell itself including the electrode in the cell moves, resulting in an eccentric error, and the diffraction angle deviates from the original value.

  On the other hand, when the laminate cell 10 is supported by the sample holder 21, even if gas is generated in the laminate cell 10 due to repeated charge and discharge, both surfaces of the laminate cell 10 are pressed by the pair of support members 22a and 22b. Therefore, the swelling of the laminate cell 10 is suppressed. Therefore, the relative positional relationship between the positive electrode 11 and the negative electrode 12 hardly changes, and the electrical connection state between the two is kept good. Thereby, even if it is the conditions which gas generate | occur | produces in the lamination cell 10 during a measurement, the charging / discharging of the lamination cell 10 can be performed appropriately. Therefore, the analysis data obtained by the X-ray analysis of the laminate cell 10 correctly reflects the charge / discharge state of the laminate cell 10. As a result, it is possible to perform highly reliable X-ray analysis with almost no influence even after gas generation. Moreover, since the sample holder 21 can be easily manufactured at low cost, an advantage that the industrial value is very high can be obtained.

  Further, in the embodiment of the present invention, the size of the X-ray transmission hole 26b formed in one (X-ray transmission side) support member 22b is increased as the distance from the support surface 25b side increases. For this reason, when X-ray diffraction measurement is performed, interference between the X-rays diffracted in the laminate cell 10 and the support member 22b can be avoided. Thereby, the X-ray can be taken into the X-ray detector 4 without reducing the intensity of the X-ray diffracted in the laminate cell 10 as much as possible. Therefore, highly accurate analysis data can be obtained in X-ray diffraction measurement.

  Further, in the embodiment of the present invention, due to the configuration of the sample holder 21, the laminate cell 10 is not directly sandwiched between the pair of support members 22a and 22b, but on the support surfaces 25a and 25b of the respective support members 22a and 22b. The laminated cell 10 is directly sandwiched between the pasted window members 23a and 23b. For this reason, the window members 23a and 23b that close the X-ray transmitting holes 26a and 26b of the support members 22a and 22b come into contact with the main surface of the laminate cell 10, and the laminate cell 10 is sandwiched between the window members 23a and 23b. . Therefore, when the window members 23a and 23b are not provided, the gas generated in the laminate cell 10 accumulates in the X-ray transmitting hole 26 and the laminate cell 10 may locally swell. When the members 23a and 23b are provided, such a fear is eliminated. For this reason, the abnormality of charging / discharging accompanying the local swelling of the laminate cell 10 can be prevented.

  In order to suppress local swelling of the laminate cell 10 with the window members 23a and 23b, in order to increase the rigidity of the window members 23a and 23b, for example, the window members 23a and 23b are made of metal, or the window member. A technique such as increasing the thickness dimension of 23a and 23b is conceivable. However, when X-ray analysis is performed, it is necessary to transmit X-rays to the window members 23a and 23b. Therefore, when the above-described method is employed, the X-ray transmittance of the window members 23a and 23b is significantly reduced. End up. As a result, the X-ray analysis itself may be impossible. Therefore, the constituent materials of the window members 23a and 23b must have high X-ray transmittance and high rigidity. Examples of the constituent material of the window members 23a and 23b having such properties include the above-described carbon fiber reinforced plastic. The carbon fiber reinforced plastic has high rigidity even at the same thickness and has the same X-ray transmittance as compared with a Kapton film which is a kind of X-ray window material. Moreover, the carbon fiber reinforced plastic does not have the handling difficulty like metal beryllium.

  As for the thickness dimensions of the window members 23a and 23b, appropriate dimensions vary depending on the energy of X-rays used for X-ray analysis. For example, when the X-ray having an energy of about 8000 eV used for general X-ray analysis is used and the window members 23a and 23b are made of carbon fiber reinforced plastic, the thickness dimension of the window members 23a and 23b is It is desirable to be 0.2 mm. Incidentally, the X-ray transmittance when an X-ray having an energy of about 8000 eV is incident on the window members 23a and 23b made of carbon fiber reinforced plastic having a thickness of 0.2 mm is 80% or more. Therefore, the X-ray analysis of the laminate cell 10 is performed even when the window members 23a and 23b are attached to the support surfaces 25a and 25b of the support members 22a and 22b so as to close the X-ray transmission holes 26a and 26b. It is possible. Moreover, since the window members 23a and 23b made of carbon fiber reinforced plastic have sufficient rigidity, even if gas is generated by charging and discharging at a high voltage, the swelling of the laminate cell 10 is suppressed, and the reliability is high. X-ray analysis can be performed.

In the embodiment of the present invention, the first pressing means (30, 31) for pressing the four corners of the support members 22a, 22b and the vicinity of the X-ray transmitting holes 26a, 26b of the support members 22a, 22b are pressed. The holding means 24 is constituted by the second holding means (32a, 32b). For this reason, the following effects are acquired.
That is, when the pair of support members 22a and 22b are pressed only by the first pressing means, the central portions (X-ray transmitting holes 26a) of the support members 22a and 22b apart from the four corners P1 to P4 of the support members 22a and 22b. , 26b) is not applied with sufficient pressing force, and there is a risk of insufficient pressing force. In particular, in the portions where the X-ray transmission holes 26a and 26b are formed, the window members 23a and 23b are not backed by the support members 22a and 22b, so that the pressing force is likely to be insufficient. On the other hand, when the pair of supporting members 22a and 22b is pressed only by the second pressing means, sufficient pressing force does not act on the four corners of the supporting members 22a and 22b apart from the X-ray transmitting holes 26a and 26b, There is therefore a risk that the holding force will be insufficient.

  On the other hand, when the pair of support members 22a and 22b are simultaneously pressed by both the first pressing means and the second pressing means, the above-described lack of pressing force is compensated for each other. For this reason, the whole lamination cell 10 can be pressed down with good balance via a pair of supporting members 22a and 22b. Further, it is not necessary to increase the rigidity of the support members 22a and 22b to be thicker than necessary. In addition, if the pressing points by the second pressing means are set at two points P5 and P6 spaced apart from the X-ray transmitting holes 26a and 26b, the vicinity of the X-ray transmitting holes 26a and 26b. Can be pressed in a balanced manner with a uniform force.

  Further, if the pair of support members 22a and 22b is made of an insulating material, for example, during the operation of connecting the terminals for charging and discharging to the laminate cell 10, the terminals should be supported by the support member 22a. , 22b does not cause a short circuit. For this reason, work safety can be ensured.

<6. Modified example>
The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications and improvements as long as the specific effects obtained by the constituent elements of the invention and combinations thereof can be derived.

  For example, in the above embodiment, as a preferred mode, the pressing means 24 is constituted by the first pressing means (30, 31) and the second pressing means (32a, 32b). The pressing means 24 may be configured by only the first pressing means or the second pressing means. Moreover, although the press part by the 2nd press means was made into two places, it is not restricted to this, Three or more places may be sufficient. Further, the pressing force when pressing the pair of support members 22a and 22b with the pressing means 24 restricts the separation of the pair of support members 22a and 22b even when gas is generated in the laminate cell 10, and Any size may be used as long as the swelling can be suppressed.

  Moreover, in the said embodiment, as a preferable aspect, the window members 23a and 23b are affixed on the support surfaces 25a and 25b of a pair of support members 22a and 22b, respectively, and the laminate cell 10 is attached via these window members 23a and 23b. However, the present invention is not limited to this, and the laminate cell 10 may be directly sandwiched between the support surfaces 25a and 25b of the pair of support members 22a and 22b.

In the above embodiment, the size of the X-ray transmission hole 26b formed in the support member 22b on the X-ray transmission side is increased as the distance from the support surface 25b increases. However, the present invention is not limited to this. As shown in FIG. 11, the support member 22a on the X-ray incident side may similarly increase the size of the X-ray transmission hole 26a as the distance from the support surface 25a increases. In that case, the X-ray transmission hole 26a and the X-ray transmission hole 26b may be set to the same size and shape, or may be set to different sizes and shapes.
When the configuration shown in FIG. 11 is adopted, the X-ray incident angle can be varied on the X-ray incident side as compared with the above-described embodiment (FIG. 3), so that X-ray diffraction measurement can be performed at a wider angle. It can be carried out. Further, if the diffraction angle is within the same range (for example, up to 2θ = 60 degrees), the opening angle of the X-ray transmission holes 26a and 26b can be made relatively small.

  Further, as the form of each support member 22a, 22b, for example, as shown in FIG. 12 and FIG. 13, by attaching mounting pieces 28a, 28b integrally to each support member 22a, 22b, each support member 22a. 22b may have an L-shaped plate structure. The mounting pieces 28a and 28b are installed on the sample table 2 and fixed by screwing or the like when the laminate cell 10 is set on the sample table 2 (see FIG. 1) using the support members 22a and 22b. Part.

  Further, in the above embodiment, the X-ray transmitting hole 26b of the support member 22b is formed in a circular shape when viewed from the front. However, interference with the diffracted X-rays within the range of the diffraction angle to be measured by the X-ray detector 4 occurs. As long as the shape can be avoided, the X-ray transmitting hole 26b may be formed in any shape.

DESCRIPTION OF SYMBOLS 10 ... Laminate cell 21 ... Sample holder 22a, 22b ... Support member 23a, 23b ... Window member 24 ... Holding means 25a, 25b ... Support surface 26a, 26b ... X-ray transmission hole

Claims (4)

A battery element formed by laminating a positive electrode and a negative electrode with a separator in between is used as a sample of a thin plate-like laminate cell sealed with a laminate film together with an electrolytic solution, and X-rays are applied to the laminate cell to obtain analysis data A sample holder for use in situ X-ray analysis,
A pair of support members that sandwich and support the laminate cell from both sides;
Pressing means for pressing the pair of support members so that the pair of support members are not separated from each other,
Each of the pair of support members has a support surface disposed so as to face the main surface of the laminate cell, and an X-ray transmission hole that transmits the X-rays,
The sample holder, wherein the size of the X-ray transmitting hole formed in at least one of the pair of support members increases as the distance from the support surface increases. The sample holder according to claim 1, wherein the X-ray transmission hole formed in the at least one support member is formed in a truncated cone shape. The inner surface of the hole for X-ray transmission formed in said at least one support member is formed in the taper shape which makes a uniform inclination over the whole thickness direction of the said support member. The sample holder described in 1. A battery element formed by laminating a positive electrode and a negative electrode with a separator in between is used as a sample of a thin plate-like laminate cell sealed with a laminate film together with an electrolytic solution, and X-rays are applied to the laminate cell to obtain analysis data -In situ X-ray analysis,
The laminate cell is supported by being sandwiched by a pair of support members from both sides, and the pair of support members are pressed so that the pair of support members are not separated from each other, and X-ray transmitting holes are respectively formed in the pair of support members. Forming and expanding the size of the X-ray transmitting hole formed in at least one of the pair of support members as the distance from the laminate cell increases. An X-ray analysis method, wherein X-ray analysis of the laminate cell is performed while avoiding interference.

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