JP5365089B2 - Electrode performance evaluation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode performance evaluation device in which a non-destructive inspection of a highly precise evaluation on electrode resistance and electrode capacity is possible regarding positive and negative electrode respectively. <P>SOLUTION: The electrode performance evaluation device is constituted of a simulated battery cell body 11, a charge and discharge device, and the electrode performance evaluation device. The simulated battery cell body 11 is constituted of the positive electrodes 15A, 15B, negative electrodes 16A, 16B, and two electrode support bodies 14A, 14B which respectively support the reference electrodes 17A, 17B. Each electrode support body is equipped with through-holes 23A, 23B contacted and opposedly arranged on the circumference with the same distance from the center of the rotation at positions where the distances along the circumference direction become equal, and has an electrode terminal 25 in which each electrode is joined to the electrode installation part in the interior of the through-hole, and inserted into the through-hole so that the electrode, charge and discharge device, and the electrode evaluation device are connected. When the second electrode support body 14B is rotated and the imitation cell arrangement and the electrode evaluation cell arrangement are formed, the through-holes of respective electrode support bodies are connected so as to form an electrolytic solution pool. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an electrode performance evaluation apparatus, and more particularly to a battery electrode performance evaluation apparatus capable of evaluating electrode resistance and electrode capacity of positive and negative battery electrodes such as lithium ion secondary batteries.

  With the widespread use of portable devices and cordless devices such as mobile phones, video cameras, laptop computers, etc., there is a strong demand for higher performance batteries that supply power to these devices. The demand for rechargeable secondary batteries is particularly increasing. Also in the field of automobiles, development of electric vehicles and hybrid vehicles equipped with secondary batteries has been actively conducted due to environmental problems and resource problems. As a high performance secondary battery mounted on an electric vehicle or the like, a lithium ion battery having a high energy density, a long life, and excellent safety can be mentioned.

  Batteries such as lithium ion batteries are mainly composed of positive and negative battery electrodes and an electrolytic solution, and the performance of each member has been greatly improved by improving the performance of each member. Generally, in battery research and development, material design and structural design are performed for each of these components, and performance evaluation is also performed individually. Performance evaluation in research and development is extremely important in performing optimal material design and structural design by analyzing factors related to high performance or performance degradation, and high-precision evaluation is always required. Since positive and negative battery electrodes also have greatly different constituent materials and structures, it is necessary to carry out evaluation for each electrode in order to perform highly accurate performance evaluation for battery electrodes.

  The method of evaluating performance in units of positive and negative electrodes can be broadly divided into the reference electrode method (three-electrode method) or alternating current in which measurement is performed by inserting a reference electrode (a supplementary electrode is also inserted if necessary) into the battery cell. Nondestructive inspection such as impedance method, and destructive inspection in which the battery is disassembled and evaluated. Here, as a performance evaluation of a secondary battery electrode such as a lithium ion battery, a durability test for evaluating a deterioration level (measurement of changes in electrode resistance and electrode capacity) after repeated predetermined charging / discharging is often performed. . The reference electrode method is the most basic electrochemical measurement method, but it is difficult to insert a reference electrode or the like, and the electrode resistance is measured by inserting a reference electrode in a battery cell in which positive and negative electrodes exist. However, the influence of the other electrode that is not evaluated cannot be completely eliminated. In addition, the AC impedance method can apply a minute AC signal to the battery cell and estimate the degradation level of each part of the electrode from the voltage / current response signal. However, the signal (resistance component) of the positive and negative electrodes is completely It is difficult to separate, and like the reference electrode method, the influence of the other electrode cannot be completely eliminated. On the other hand, when each electrode is disassembled and evaluated by destructive inspection, although the influence of the other electrode can be eliminated, the evaluation takes a long time, and further, there is a problem that the subsequent durability test cannot be continued. .

  Patent Document 1 discloses a method that is a nondestructive inspection and can be evaluated without being affected by other factors for each electrode. In Patent Document 1, based on the imaging principle of X-ray computer tomography (CT), the CT value of at least one region of at least one of the positive electrode mixture layer and the negative electrode mixture layer in the laminated section of the electrode body of the secondary battery. A method for evaluating the state of a secondary battery, including a CT value measuring step for measuring and a deterioration state evaluating step for evaluating the deterioration state of the secondary battery based on the CT value obtained by the measurement, is disclosed. Further, in Patent Document 1, the X-ray CT image data indicates the electrode stacking state such as the position of the electrode body, peeling and collapsing of the electrode mixture from the current collector, and the gap in the stacking interval between the electrodes. It is stated that it can be observed.

JP 2001-203003 A

  However, in the evaluation method described in Patent Document 1, it is possible to observe the laminated state of the electrodes in a non-destructive manner, but it is impossible to measure the electrode resistance and the electrode capacitance, which are extremely important evaluation items in the electrode performance evaluation. .

  An object of the present invention is to provide an electrode performance evaluation apparatus that is a non-destructive inspection and that enables high-precision evaluation of positive and negative electrodes for electrode resistance and electrode capacitance, which are important evaluation items.

An electrode performance evaluation apparatus according to the present invention includes at least two electrode supports that support positive and negative electrodes that are performance evaluation targets, and an electrolytic solution that fills an electrode gap, and changes the relative positions of the two electrode supports. A pseudo cell main body forming a pseudo cell arrangement and an electrode evaluation cell arrangement , a charge / discharge device for charging / discharging the pseudo cell, and an electrode evaluation device for evaluating an electrode of the electrode evaluation cell. The main body has at least a first electrode support that supports the first positive electrode and the first negative electrode, and a second electrode support that supports at least the second positive electrode and the second negative electrode. By changing the relative position of the support, the pseudo cell arrangement in which the first positive electrode and the second negative electrode and the first negative electrode and the second positive electrode face each other to charge and discharge, the first positive electrode and the first positive electrode 2 positive electrode and 1st negative electrode and 2nd negative electricity An electrode resistance evaluation cell arrangement for measuring the electrode resistance of the positive and negative electrodes with the electrodes facing each other is formed.

  The first and second electrode supports further have first and second reference electrodes that serve as counter electrodes for the positive and negative electrodes when measuring the electrode capacities of the positive and negative electrodes, respectively. In addition to the pseudo cell arrangement and the electrode resistance evaluation cell arrangement, the first positive electrode and the second reference electrode, the first negative electrode and the second reference electrode, the first reference electrode and the second positive electrode It is preferable to form an electrode capacity evaluation cell arrangement in which the electrode and the first reference electrode and the second negative electrode face each other and the electrode capacity of the positive and negative electrodes is measured.

  Each electrode support has a disk shape that is relatively rotatable, the disk surfaces are arranged to face each other, and a rotation center that is a center of rotation is formed on the disk surface, and so on. Each electrode is supported or fixed at a position on the circumference of the distance where the distance between the electrodes along the circumferential direction is equal, and at least one of the two electrode supports is rotated to change its relative position. Thus, when forming the pseudo cell arrangement and the electrode evaluation cell arrangement, it is preferable to form an electrolyte reservoir for filling the gap between the electrodes arranged opposite to each other.

  In addition, the electrode supports are arranged to face each other with the disk surfaces in contact with each other, and penetrate the electrode support at a position on the circumference that is equidistant from the center of rotation and at equal distances along the circumferential direction. A through-hole electrode installation member that includes a through-hole and that supports or fixes the electrode is provided inside the through-hole. The through-hole electrode installation member is inserted into the through-hole and is in contact with the electrode that is supported or fixed by the through-hole electrode installation member. Each electrode support has an electrode terminal that connects at least one of the discharge device and the electrode evaluation device, and rotates at least one of the two electrode supports to form a pseudo cell arrangement and an electrode evaluation cell arrangement. The through holes are connected to each other to form an electrolytic solution reservoir, and at least one electrode support preferably has an electrolytic solution filling path for filling the electrolytic solution reservoir with the electrolytic solution.

  The electrolyte solution filling path includes an electrolyte solution introduction path for introducing an electrolyte solution formed through the electrode support from the inner disk surface, an electrolyte solution delivery path for deriving excess electrolyte solution, and an internal An electrolyte solution groove formed on the disk surface, one end of which is connected to the electrolyte introduction through passage, the other through hole is connected to the electrolyte outlet through passage, and the other end is connected to the electrolyte outlet passage. An electrolyte flow path is formed when the disk surface of one electrode support and the disk surface of the other electrode support are in contact with each other, and at least one of the two electrode supports is rotated. When forming the cell arrangement, it is preferable that each electrolytic solution reservoir is filled with the electrolytic solution from the electrolytic solution introduction passage through the electrolytic solution flow passage, and surplus electrolytic solution is led out from the electrolytic solution outlet passage.

  According to the electrode performance evaluation apparatus according to the present invention, the pseudo cell main body supports at least the first positive electrode and the first negative electrode, and supports at least the second positive electrode and the second negative electrode. A second electrode support, and by changing the relative position of the two electrode supports, a pseudo cell arrangement and an electrode resistance evaluation cell arrangement for measuring electrode resistance are formed. The electrode resistance, which is an important item, can be evaluated for each positive and negative electrode with high accuracy without being disassembled, that is, by nondestructive inspection.

  The first and second electrode supports further have first and second reference electrodes that serve as counter electrodes for the positive and negative electrodes when measuring the electrode capacities of the positive and negative electrodes, respectively. By changing the relative position of the electrode, the electrode capacity evaluation cell arrangement for measuring the electrode capacity of each positive and negative electrode is formed. By nondestructive inspection, the evaluation of the electrode capacity, which is an important item, is high for each positive and negative electrode. Can be implemented with accuracy.

  Each electrode support has a disk shape that is relatively rotatable, the disk surfaces are arranged to face each other, and a rotation center that is a center of rotation is formed on the disk surface, and so on. Each electrode is supported or fixed at a position where the distance between the electrodes along the circumferential direction is equal on the circumference of the distance, and the electrodes are arranged to face each other by rotating at least one of the two electrode supports If the electrolyte solution reservoir for filling the electrolyte solution in the gap is formed, the charge / discharge cycle and the performance evaluation can be repeatedly performed only by rotating the electrode support. Further, a plurality of performance evaluations can be performed simultaneously in one apparatus, and electrode performance evaluation such as a durability test can be performed easily and quickly.

  In addition, the electrode supports are arranged to face each other with the disk surfaces in contact with each other, and penetrate the electrode support at a position on the circumference that is equidistant from the center of rotation and at equal distances along the circumferential direction. A through-hole electrode installation member that includes a through-hole and that supports or fixes the electrode is provided inside the through-hole. The through-hole electrode installation member is inserted into the through-hole and is in contact with the electrode that is supported or fixed by the through-hole electrode installation member. Having an electrode terminal that connects at least one of the discharge device and the electrode evaluation device, by rotating at least one of the two electrode supports, the through holes of each electrode support are connected to form an electrolyte reservoir, Furthermore, if the at least one electrode support is configured to have an electrolyte filling path for filling the electrolyte reservoir with the electrolyte solution, a simplified apparatus can be realized, and the electrode performance evaluation can be performed easily and quickly. Further improve be able to.

  The electrolyte solution filling path includes an electrolyte solution introduction path for introducing an electrolyte solution formed through the electrode support from the inner disk surface, an electrolyte solution delivery path for deriving excess electrolyte solution, and an internal An electrolyte solution groove formed on the disk surface, one end of which is connected to the electrolyte introduction through passage, the other through hole is connected to the electrolyte outlet through passage, and the other end is connected to the electrolyte outlet passage. If an electrolyte flow passage is formed by contact of the disk surface of one electrode support and the disk surface of the other electrode support, the operation of filling the electrolyte reservoir with the electrolyte is extremely easy. Become.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following description, the electrode performance evaluation apparatus will be described as a performance evaluation apparatus for secondary battery electrodes, but is not limited to batteries, and is also used for performance evaluation of capacitor electrodes such as electric double layer capacitors that can be charged and discharged. be able to.

  FIG. 1 is a block diagram showing a configuration of a secondary battery electrode performance evaluation apparatus. FIG. 2 is a diagram showing a state where two electrode supports constituting the pseudo battery cell main body are separated. FIG. 3 is a view showing a state in which the electrode support is disposed in contact with and opposed to the structure shown in FIG. FIG. 4 is a schematic view showing a cross-section of the main part of FIG. 3 (stopper 33 omitted).

  As shown in FIG. 1, a secondary battery electrode performance evaluation apparatus 10 (hereinafter referred to as a performance evaluation apparatus 10) includes a pseudo battery cell body 11 as a main component. The pseudo battery cell main body 11 is a member that forms a model (pseudo battery cell) of a battery cell (unit cell) and an electrode evaluation cell for evaluating an electrode. The performance evaluation device 10 includes a charge / discharge device 12 and an electrode evaluation device 13 which are indispensable components for performing performance evaluation of battery electrodes.

  The battery to which the performance evaluation device 10 can be applied, that is, the battery formed by the pseudo battery cell body 11 of the performance evaluation device 10 is preferably a chargeable / dischargeable secondary battery. Specific examples include lithium ion batteries, lead storage batteries, sealed nickel-cadmium batteries, nickel metal hydride batteries, nickel zinc batteries, and lithium metal batteries. In the following description, the positive and negative electrodes of a lithium ion battery are mainly described as examples of the evaluation target electrode, but the evaluation target is not limited to this.

  The electrodes to be evaluated by the performance evaluation apparatus 10 are generally a current collector (electrode base material) made of aluminum foil or the like, and an electrode active material layer (this specification and drawings) formed on the surface of the current collector. Then, the electrode active material layer may be referred to as an electrode in some cases). The electrode active material layer contains a particulate active material, a conductivity imparting material (acetylene black or the like), and a binder resin (polyvinylidene fluoride or the like) for binding them. In lithium ion batteries, lithium compounds such as lithium cobaltate, lithium nickelate, and lithium manganate are used as the positive electrode active material, and carbon materials such as graphite are used as the negative electrode active material.

  The shape and size of the positive and negative electrodes evaluated by the performance evaluation device 10 are not particularly limited due to the configuration of the present invention, and can be arbitrarily set. For example, in the case of a Li-ion battery, ternary or olivine can be used for the positive electrode, and Li metal or fluorine-based material may be used for the negative electrode. The electrode material can also be set arbitrarily. The application can be extended to all batteries having a liquid electrolyte. As an actual battery configuration, for example, a sheet-like positive electrode (positive electrode sheet) and a negative electrode sheet are overlapped via a separator such as a porous polyolefin sheet, and wound as a wound electrode body. It is housed in a suitable container together with the electrolyte. Accordingly, the shape of the positive and negative electrodes is preferably a sheet shape (thin film shape) that is in conformity with the actual battery configuration. In addition, since electrode capacity and the like described later are defined as numerical values per unit area or unit weight of the electrode, in order to improve evaluation accuracy, the size (area, thickness, weight, etc.) of the electrode is accurately measured. It is necessary to keep.

  Items that can be evaluated by the performance evaluation apparatus 10 are electrode resistance (single pole resistance) and electrode capacity (single pole capacity), which are extremely important evaluation items in electrode performance evaluation. Generally, when a lithium ion battery is repeatedly charged and discharged, the range of use of the battery becomes narrow due to an increase in electrode resistance, or the electrode capacity decreases. The main cause of the increase in resistance and the decrease in capacity is that the lithium-containing compound is gradually deposited on the negative electrode surface by repeated charging and discharging, and the amount of movable lithium ions is reduced. Therefore, the electrode capacity (= battery capacity) is reduced, and a passive film is further formed on the negative electrode surface. As a result, the electrode resistance is increased and the battery output is also greatly reduced. Thus, in the lithium ion battery, the charge / discharge characteristics are extremely important performance, and the durability test for evaluating the deterioration state of the electrode after repeated charge / discharge is an important performance evaluation test. Is a device suitable for this durability test.

  The charging / discharging device 12 can be used without particular limitation as long as it is a device that can repeatedly charge and discharge the pseudo battery cell, and examples thereof include known charging / discharging devices such as potentiostats and galvanostats. it can. It is also possible to use a potentio / galvanostat (multistat 1470E type; manufactured by Rollertron, etc.) in which the functions of potentiostat (potential control) and galvanostat (current control) are integrated.

  The electrode evaluation device 13 can be used without any particular limitation as long as it can measure the electrode resistance and the electrode capacitance in the electrode evaluation cell. For example, in the measurement of electrode capacity, the same potentio / galvanostat as that of the charge / discharge device 12 can be used. In the measurement of electrode resistance, an impedance analyzer (frequency response analyzer; FRA) can be used. Generally, FRA is connected to a potentiostat. In the electrode evaluation, not only measurement by constant voltage or constant current charging / discharging but also measurement methods such as a cyclic voltammetry method and a pulse method can be employed.

  As shown in FIG. 1, the pseudo battery cell body 11 includes two electrode supports 14A (referred to as a first electrode support 14A) and an electrode support 14B (referred to as a second electrode support 14B). A battery electrode to be evaluated is supported or fixed on the electrode support 14. Here, although the pseudo battery cell main body 11 can also have three or more electrode support members 14, it is preferable that it is two from viewpoints, such as simplification of evaluation operation, and the electrode support body 14 is the following. This will be described as two. As described above, the pseudo battery cell main body 11 is a member that forms a pseudo battery cell and an electrode evaluation cell that are models of the battery cell, and these cells are formed by the two electrode supports 14. Note that “supporting the electrode” means that the electrode is detachably installed, and fixing the electrode means that the electrode cannot be removed or is extremely difficult to remove. Since the electrode is generally exchanged when is completed, the electrode is preferably supported.

  Each electrode support 14 supports at least one positive electrode 15 and one negative electrode 16. When each electrode support 14 has the positive electrode 15 and the negative electrode 16, the first positive electrode 15A, the second negative electrode 16B, and the first negative electrode 16A are changed by changing the relative positions of the two electrode supports 14. A pseudo battery cell arrangement in which the second positive electrode 15B is oppositely charged and discharged, and the first positive electrode 15A and the second positive electrode 15B, and the first negative electrode 16A and the second negative electrode 16B are oppositely positive and negative electrodes. An electrode resistance evaluation cell arrangement for measuring each electrode resistance can be formed. Therefore, according to the performance evaluation apparatus 10, it is possible to measure the electrode resistance, which is the most important evaluation item in the durability test, without disassembling the pseudo battery cell body 11. Thus, since it is not necessary to disassemble the pseudo battery cell main body 11, the same conditions are maintained without changing conditions (battery cell state) such as the distance between electrodes and the electrode installation pressure before and after the electrode resistance evaluation. Thus, the durability test can be continued.

  As shown in FIG. 1, in addition to the positive electrode 15 and the negative electrode 16, each electrode support 14 preferably supports or fixes a reference electrode 17 that is a reference electrode when measuring the electrode capacitance. Specifically, the first electrode support 14A includes a first positive electrode 15A and a first negative electrode 16A to be evaluated, and a first reference electrode 17A to be an evaluation reference. Similarly, the second electrode support 14B has a first positive electrode 15A, a first negative electrode 16A, and a first reference electrode 17A. When each electrode support 14 has the reference electrode 17, the first positive electrode 15 </ b> A and the second positive electrode 15 </ b> A and the second positive electrode 15 </ b> A are added in addition to the pseudo battery cell arrangement and the electrode resistance evaluation cell arrangement by changing the relative positions of the two electrode supports 14. The reference electrode 17B, the first negative electrode 16A and the second reference electrode 17B, the first reference electrode 17A and the second positive electrode 15B, and the first reference electrode 17A and the second negative electrode 16B are opposed to each other. An electrode capacity evaluation cell arrangement for measuring capacity can be formed. Therefore, it is possible to measure the electrode capacity, which is an important evaluation item in the durability test, without disassembling the pseudo battery cell main body 11. Here, as described above, the reference electrode 17 is an electrode serving as a measurement reference when measuring the electrode capacity. In the lithium ion battery, it is preferable to use a reference electrode made of lithium metal.

  Each electrode support 14 can also support four or more electrodes. For example, two positive electrodes 15, two negative electrodes 16, and two reference electrodes 17 can be supported. The first electrode support 14A supports two positive electrodes 15 and one negative electrode 16, and second The electrode support 14 </ b> B may be a combination of different electrodes depending on the electrode support 14 so as to support one positive electrode 15 and two negative electrodes 16. Furthermore, the number of electrodes supported by the electrode support 14 can be changed, but the number of electrodes supported is preferably the same from the viewpoint of improving the efficiency of performance evaluation. Below, the number of electrodes supported or fixed to each electrode support 14 constituting the pseudo battery cell body 11 will be described as the same number.

  Further, when the pseudo battery cell arrangement and the electrode evaluation cell arrangement are formed and the electrodes are arranged to face each other, an electrolytic solution reservoir 18 filled with an electrolytic solution is formed in each electrode gap. When the electrolytic solution reservoir 18 (electrode gap) with the pseudo battery cell arrangement is filled with the electrolytic solution, the pseudo battery cell is completed, and when the electrolytic solution reservoir 18 with the electrode evaluation cell arrangement is filled with the electrolytic solution, the electrode evaluation cell is completed. To do. Here, the electrolytic solution is not particularly limited in terms of the configuration of the present invention, and a known electrolytic solution can be used. In a lithium ion battery, for example, lithium hexafluorophosphate, lithium tetrafluoroborate, or the like is used as an solute (electrolyte) in an organic solvent such as propylene carbonate (PC), ethylene carbonate (EC), or diethyl carbonate (DEC). The added organic electrolyte can be used.

  As described above, each electrode support 14 constituting the pseudo battery cell main body 11 has a function of supporting or fixing each electrode to be evaluated and evaluation criteria, and at least one of the electrode supports 14 moves. It is necessary to have a function of changing the relative position.

  As the form of the electrode support 14, various forms can be adopted as long as each electrode can be supported or fixed and can be relatively moved. For example, the electrode support 14 has a rectangular plate shape. And a form that slides up and down or left and right, and a form that is cylindrical or disk-shaped and rotates. Among such forms, from the viewpoint of simplification of operation and speeding up of evaluation, it is preferable that the form is a disk shape and rotates.

  Each disk-shaped electrode support 14 needs to be able to change the relative position, and it is preferable to change the relative position by relatively rotating as described above. Specifically, the pseudo battery cell main body 11 is configured such that each electrode support 14 is disposed so that the disk surfaces thereof face each other. Each electrode support 14 has a center of rotation that is the center of relative rotation at the center of the opposingly disposed disk surfaces.

  Each electrode support 14 supports or fixes each electrode at a position on the circumference equidistant from the center of rotation and at a uniform distance along the circumferential direction. That is, when the disk surfaces of the electrode supports 14 are opposed to each other so that the rotation centers overlap (all rotation operations are added as necessary), all the electrodes supported or fixed to the electrode supports 14 are opposed to each other. become. By arranging the electrodes in this way, it becomes easy to form the pseudo battery cell arrangement and the electrode evaluation cell arrangement, and the simplification and speeding up of the durability test are promoted.

  When the disk surfaces of the electrode supports 14 are arranged to face each other, it is possible to arrange them at a predetermined interval, or to place the disk surfaces in contact with each other. When facing each other with a predetermined interval, for example, an adapter for forming the electrolyte reservoir 18 can be sandwiched. In addition, since the electrodes supported by the respective supports are not in contact with each other when the electrode supports 14 are arranged opposite to each other, it is not necessary to provide a separator that is a general battery component between the electrode supports 14. . In addition, as an arrangement | positioning form of each electrode support body 14, as shown in FIG. 3, the form which contacts and arrange | positions disk surfaces mutually is preferable.

  In FIG. 2, the pseudo battery cell main body 11 composed of two disk-shaped electrode supports 14 is shown. Each electrode support 14 supports a positive electrode 15, a negative electrode 16, and a reference electrode 17, and can evaluate electrode resistance and electrode capacitance as described above. FIG. 3 is a view in which the disk surfaces of the electrode supports 14 are arranged in contact with each other and viewed from the side of the first electrode support 14A. In the following, a mode in which the disk surfaces are mainly arranged in contact with each other will be described.

  Here, the electrode arrangement supported by the electrode support 14 is a position on the circumference equidistant from the center of rotation and the distance along the circumferential direction is equal, as described above. From the viewpoint of speeding up the durability test, it is preferable to specify the arrangement order of the electrodes. Specifically, as shown in FIG. 2, in the first electrode support 14A, the electrodes are supported at intervals of 120 °, and the negative electrode 16A and the positive electrode 15A are formed clockwise from the reference electrode 17A. Similarly, in the second electrode support 14B, a negative electrode 16B and a positive electrode 15B are formed clockwise from the reference electrode 17B. That is, the electrodes are preferably attached to each electrode support 14 in the same order. With such an electrode arrangement, as shown in FIG. 3, when the two electrode supports 14 are arranged in contact with each other, the first positive electrode 15A, the second negative electrode 16B, the first negative electrode 16A and the second electrode Two pseudo battery cell arrangements in which the positive electrodes 15B face each other can be formed. Therefore, a long charge / discharge process can be performed simultaneously.

  As shown in FIG. 2, the pseudo battery cell main body 11 preferably includes a fixing base 19 on which each electrode support 14 is set. The fixed base 19 has a half-pipe structure having the same curvature as the electrode support 14 having a disk shape, and can be stably maintained in a state where the electrode support 14 is erected. The first electrode support 14A is fixed by screws 20 so as not to move, and the second electrode support 14B is not fixed to the fixing base 19 but is set to be rotatable.

  As described above, each electrode support 14 preferably has a center of rotation at the center of the disk surface. As shown in FIG. 2, a rotation shaft 21 is provided at the rotation center of the first electrode support 14A, and a rotation bearing hole 22 into which the rotation shaft 21 is inserted is provided at the rotation center of the second electrode support 14B. Can do. With such a configuration, the setting of the electrode support 14 becomes easy, and further simplification and speeding up of the durability test are promoted. Further, each electrode support 14 can be provided with various bearings and various sealing materials (O-rings, etc.) in order to improve the adhesion of the abutted disk surface.

  As shown in FIG. 2 to FIG. 4, each electrode support 14 has a circumferential distance that is equidistant from the rotation center (the rotation shaft 21 and the rotation bearing hole 22) and that extends along the circumferential direction. A through hole 23 penetrating the electrode support 14 is formed at an even position. The through hole 23 is provided to insert an electrode terminal 25 described later in order to form an electrolyte reservoir 18 in order to provide a support member for each electrode. In addition, although the shape of the hole of the through-hole 23 is not specifically limited on the structure of this invention, below, it demonstrates as a circular shape.

  A through-hole electrode installation portion 24 (hereinafter referred to as an electrode installation portion 24) is provided inside the through-hole 23. Each electrode is formed into a thin film circular shape corresponding to the shape of the through hole 23 and the electrode installation portion 24, and is joined to the electrode installation portion 24 using an adhesive or the like. The electrode installation part 24 has a ring shape protruding from the inner diameter surface of the through hole 23 and can be integrally formed in the manufacture of the electrode support 14. In addition, as shown in FIG. 4 etc., it is preferable that a thin film electrode is joined to the ring surface of the outer side of the electrode installation part 24 from a viewpoint of the connectivity improvement with the electrode terminal 25, etc. Here, the disk surface arranged in contact and opposite is an internal disk surface, the other disk surface is an external disk surface, and the ring surface outside the electrode installation portion 24 means a ring surface on the external disk surface side.

  As shown in FIG. 4, the electrode installation part 24 is provided in the position which has a predetermined distance from the disk surface (internal disk surface) which contact | abuts. By changing this predetermined distance, the distance between the electrodes can be adjusted, and the capacity of the electrolyte reservoir 18 also changes. That is, the longer the distance from the inner disk surface, the longer the distance between the electrodes and the larger the size of the electrolyte reservoir 18. Therefore, the predetermined distance can be set in consideration of the distance between the electrodes and the size of the electrolyte reservoir 18. When the electrolyte circulation groove 29 described later is provided, at least the electrolyte circulation groove 29 can be formed. It is preferable to set the distance as possible.

  The pseudo battery cell main body 11 is brought into contact with each electrode inserted from the outside into the through hole 23 and joined to the electrode installation portion 24, so that the electrode, the charge / discharge device 12 and the electrode evaluation device 13 (hereinafter referred to as charge / discharge evaluation device). ) Are connected to each other. The electrode terminal 25 is a member having a function of electrically connecting the electrode and the charge / discharge evaluation apparatus, and also has a function of stably supporting the electrode. As shown in FIG. 2, the electrode terminal 25 has a cylindrical shape, and the diameter of the cylinder is designed to be slightly smaller than the inner diameter of the through hole 23. Therefore, as shown in FIG. 4, the electrode terminal 25 can be inserted into the through hole 23, and the electrode is sandwiched and supported stably by the electrode installation portion 24 and the electrode terminal 25. The electrode terminal 25 is in pressure contact with the current collector 34 constituting the electrode, and enables charging and discharging of the pseudo battery cell.

  As shown in FIG. 3, the electrode terminal 25 inserted into the through hole 23 and pressed against the electrode can be fixed by the stopper 33. As described above, since the electrode terminal 25 is fixed by the stopper 33, there is no fear that the conductivity is lowered in the charge / discharge process or the like, and the durability test is continued while maintaining the same conditions (electrode installation pressure and the like). It is possible. Further, after the endurance test is completed, the electrode 33 can be pulled out by removing the stopper 33 and the electrode to be evaluated can be easily replaced.

  When the second electrode support 14B is rotated to form the pseudo battery cell arrangement and the electrode evaluation cell arrangement, as shown in FIG. 4, the through holes 23 of each electrode support 14 are connected to each other and the electrolyte reservoir 18 is formed. It is formed. That is, a part of the through hole 23 becomes the electrolyte reservoir 18. The size of the electrolyte reservoir 18 is determined by adjusting the distance between the electrodes, that is, the position of the electrode installation portion 24 as described above.

  As described above, the second electrode support 14B includes the operation lever 26 that can be rotated and is gripped during the rotation operation. Further, an operation lever fixing portion 27 for fixing the operation lever 26 can be provided on the fixing base 19 so that the second electrode support 14B does not rotate in the charge / discharge process or the like.

  The constituent material of the electrode support 14 is preferably a material having good insulation, chemical resistance, workability, and the like. Organic compounds (resins), inorganic compounds such as metal oxides and metal nitrides, insulation A metal material can also be applied if this can be ensured. Among these, from the viewpoints of insulation and workability, a resin material is preferable, and among them, a resin having high chemical resistance, for example, polyetheretherketone (PEEK) is preferable.

  The electrode support 14 is formed with an electrolyte filling path for filling the electrolyte reservoir 18 with the electrolyte. The electrolytic solution filling path is a flow path for supplying the electrolytic solution to the electrolytic solution reservoir 18 without disassembling the pseudo battery cell main body 11. From the viewpoint of reducing the processing cost and simplifying the electrolyte filling operation, the electrolyte filling path is preferably provided on one side of the electrode support 14. Specifically, the first electrode fixed to the fixed base 19 is provided. It is preferable to provide the support 14A.

  As shown in FIG. 2, the electrolyte solution filling path provided in the first electrode support 14 </ b> A is preferably composed of an electrolyte solution introduction path 28, an electrolyte solution flow groove 29, and an electrolyte solution lead-out path 30. . The electrolyte solution introduction path 28 and the electrolyte solution lead-out path 30 are formed through the electrode support 14A from the inner disk surface, the former is a flow path for introducing the electrolyte solution, and the latter is the excess electrolyte solution. It is a flow path for. The electrolyte solution flow groove 29 is a groove formed on the inner disk surface, one end of which is connected to the electrolyte solution introduction path 28, which communicates with each through hole 23, and the other end which is connected to the electrolyte solution outlet path 30. The electrolyte flow groove 29 is formed so that the first and second electrode supports 14A and 14B are disposed in contact with each other (FIGS. 3 and 4) so that the groove is formed by the inner disk surface of the second electrode support 14B. And the electrolyte solution passes through the electrolyte solution introduction passage 28 and passes through the electrolyte solution passage passage, and each electrolyte reservoir 18 is filled with the electrolyte solution. Excess electrolyte is led out from the electrolyte lead-out path 30.

  The first electrode support 14 </ b> A can include a syringe attachment portion 32 that installs the syringe 31 in the external opening of the electrolyte solution introduction path 30. When the filling of the electrolytic solution is completed, the excess electrolytic solution is discharged from the electrolytic solution outlet path 30 and supplied to the syringe 31 as described above. Therefore, it can be seen that when the electrolytic solution is accumulated in the syringe 31, filling of each electrolytic reservoir 18 with the electrolytic solution is completed. The syringe 31 is graduated, and the amount of electrolyte filled and the amount of gas generated during charging and discharging can be quantified.

  Electrode performance evaluation by the performance evaluation apparatus 10 having the above configuration (performance evaluation apparatus 10 shown in FIGS. 2 to 4) will be described in detail below with reference to FIG. FIG. 5 is a flowchart showing a procedure for evaluating the performance of the secondary battery electrode, and the electrode performance evaluation items are electrode resistance and electrode capacity.

  First, the positive electrode 15 and the negative electrode 16 that are evaluation targets and the reference electrode 17 that is an electrode serving as a reference for electrode capacity evaluation are attached to each electrode support 14 (S10). As described above, the electrode mounting order is preferably the same order in each electrode support 14. After the electrodes are joined to the electrode placement portions 24 of the electrode supports 14 in the same order, the electrode terminals 25 are inserted into the through holes 23 to bring the electrode terminals 25 into contact with the electrode current collectors 34. In this state, the electrode terminal 25 is fixed by the stopper 33 and can secure the electrical connection between the electrode and the charge / discharge evaluation apparatus and can stably support the electrode.

  The electrode supports 14 to which the electrodes and the electrode terminals 25 are fixed are disposed in contact with each other as shown in FIG. 3 (S11). Specifically, after the first electrode support 14A is fixed to the fixing base 19 with screws 20, the rotation shaft receiving hole 22 of the second electrode support 14B is fitted into the rotation shaft 21 of the first electrode support 14A. The second electrode support 14B is set on the fixed base 19. In this state, the inner disk surface of each electrode support 14 is in contact (contacted) with no gap. The second electrode support 14 </ b> B is rotatably installed without being screwed to the fixed base 19. When the operation lever 26 of the second electrode support 14A is rotated to the left side in FIG. 3, that is, to the position where the operation lever 26 is fitted to the operation lever fixing portion 27, a pseudo battery cell arrangement is formed. That is, the first positive electrode 15A and the second negative electrode 16B, and the first negative electrode 16A and the second positive electrode 15B face each other.

  In S <b> 11, the electrolyte solution is filled in the electrolyte solution reservoir 18 formed by arranging the electrode support members 14 so as to face each other (S <b> 12). The electrolytic solution is filled by connecting an electrolytic solution supply pump or the like to the electrolytic solution introduction path 28. Each electrolyte reservoir 18 is filled with the electrolyte from the electrolyte introduction path 28 through the electrolyte flow path (electrolyte flow groove 29), and excess electrolyte is discharged from the electrolyte lead-out path 30. At that time, the amount of the electrolyte filled with the syringe 31 can be confirmed. In S <b> 10 to S <b> 12, pseudo battery cells are configured, and preparation for the durability test is completed.

  As a durability test, first, charge / discharge of the pseudo battery cell is performed (S13). Specifically, the charge / discharge evaluation apparatus connected to the electrode via the electrode terminal 25 is operated in a predetermined pattern (for example, constant current charge / discharge) to execute the charge / discharge cycle.

  It is determined whether or not a predetermined charge / discharge cycle has been completed (S14). The predetermined charging / discharging cycle is generally several thousand to several tens of thousands of cycles, and the charging / discharging evaluation apparatus repeatedly executes charging / discharging until the predetermined number of cycles is reached.

  When the predetermined charging / discharging cycle is completed, the second electrode support 14B is rotated 120 ° rightward in FIG. 3 so that the first positive electrode 15A and the second positive electrode 15B are opposed to each other. An electrode resistance evaluation cell for the electrode 15 is formed. Further, an electrode capacity evaluation cell of the negative electrode 16 is formed in which the first negative electrode 16A and the second reference electrode 17B, and the second negative electrode 16B and the first reference electrode 17A are opposed to each other (S15). In addition, if the order of electrode arrangement in S10 is changed, the order of cell formation can be changed.

  Based on the electrode evaluation cell formed in S15, the electrode resistance evaluation of the positive electrode 15 and the electrode capacity evaluation of the negative electrode 16 are performed (S16). The evaluation is continued until the predetermined electrode evaluation is completed (S17).

  When the predetermined electrode evaluation is completed, the second electrode support 14B is further rotated 120 ° in the right direction, and the electrode of the negative electrode 16 in which the first negative electrode 16A and the second negative electrode 16B are arranged to face each other. A resistance evaluation cell is formed. Further, an electrode capacity evaluation cell of the positive electrode 16 in which the first positive electrode 15A and the second reference electrode 17B, and the second positive electrode 15B and the first reference electrode 17A are opposed to each other is formed (S18).

  Based on the electrode evaluation cell formed in S18, the electrode resistance evaluation of the negative electrode 16 and the electrode capacity evaluation of the positive electrode 15 are performed (S19). The evaluation is continued until the predetermined electrode evaluation is completed (S20).

  S13 to S20 are procedures showing one cycle from charge / discharge of the pseudo battery cell to performance evaluation, that is, one cycle of the durability test. By rotating the second electrode support 14A to the original state (up to the position where the operation lever 26 fits the operation lever fixing portion 27), the pseudo battery cell is formed again, and the charge / discharge cycle can be executed. Therefore, the cycle of S13 to S20 can be repeated, and the durability test can be continuously performed.

  Moreover, according to the performance evaluation apparatus 10, since it is not necessary to disassemble the pseudo battery cell main body 11 (that is, nondestructive inspection), conditions such as an interelectrode distance and an electrode installation pressure (before and after the electrode resistance evaluation) It is possible to continue the durability test while maintaining the same conditions without changing the state of the battery cells.

It is a block diagram which shows the structure of the performance evaluation apparatus of a secondary battery electrode. It is a figure which shows the state by which the two electrode support bodies which comprise a pseudo battery cell main body were isolate | separated. It is a figure which shows the state by which the electrode support body was contact | abutted and arranged in FIG. It is a schematic diagram which shows the principal part cross section of FIG. It is a flowchart which shows the procedure of the performance evaluation of a secondary battery electrode.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Battery electrode performance evaluation apparatus, 11 Pseudo battery cell main body, 12 Charging / discharging apparatus, 13 Electrode evaluation apparatus, 14 Electrode support body, 15 Positive electrode, 16 Negative electrode, 17 Reference electrode, 18 Electrolyte reservoir, 19 Fixing stand, 20 Screw, 21 Rotating shaft, 22 Rotating bearing hole, 23 Through hole, 24 Through hole electrode installation part, 25 Electrode terminal, 26 Operation lever, 27 Operation lever fixing part, 28 Electrolyte introduction path, 29 Electrolyte flow channel, 30 Electrolyte outlet path, 31 syringe, 32 syringe mounting part, 33 stopper, 34 current collector.

Claims (5)

A pseudo cell arrangement and an electrode evaluation cell including at least two electrode supports that support positive and negative electrodes to be evaluated for performance and an electrolyte filled in an electrode gap, by changing the relative positions of the two electrode supports. A pseudo cell body for forming the arrangement , a charge / discharge device for charging / discharging the pseudo cell, and an electrode evaluation device for evaluating the electrodes of the electrode evaluation cell,
The pseudo cell body is
A first electrode support that supports at least the first positive electrode and the first negative electrode;
A second electrode support that supports at least the second positive electrode and the second negative electrode;
Have
By changing the relative positions of the two electrode supports, a pseudo-cell arrangement in which the first positive electrode and the second negative electrode and the first negative electrode and the second positive electrode face each other to charge and discharge, and the first positive electrode An electrode performance evaluation apparatus comprising an electrode resistance evaluation cell arrangement in which an electrode and a second positive electrode and a first negative electrode and a second negative electrode are opposed to each other to measure the electrode resistance of the positive and negative electrodes. In the electrode performance evaluation apparatus according to claim 1,
The first and second electrode supports are
Furthermore, when measuring the electrode capacity of each of the positive and negative electrodes, each of the first and second reference electrodes that are counter electrodes of the positive and negative electrodes,
By changing the relative position of the two electrode supports, in addition to the pseudo cell arrangement and the electrode resistance evaluation cell arrangement, the first positive electrode and the second reference electrode, the first negative electrode and the second reference electrode, the first reference An electrode capacity evaluation cell arrangement for measuring an electrode capacity of a positive electrode and a negative electrode with an electrode and a second positive electrode, and a first reference electrode and a second negative electrode facing each other. In the electrode performance evaluation apparatus according to claim 1 or 2,
Each electrode support is
It is a relatively rotatable disk shape, the disk surfaces are arranged opposite to each other, and a rotation center that is the center of rotation is formed on the disk surface,
Each electrode is supported or fixed at a position on the circumference equidistant from the center of rotation and the distance between the electrodes along the circumferential direction is equal,
By rotating at least one of the two electrode supports and changing the relative position thereof, when forming the pseudo cell arrangement and the electrode evaluation cell arrangement, the gap between the electrodes arranged opposite to each other is filled with the electrolytic solution. An electrode performance evaluation apparatus, wherein an electrolyte reservoir is formed. In the electrode performance evaluation apparatus according to claim 3,
Each electrode support is
The disk surfaces are in contact with each other and arranged to face each other.
Provided with a through-hole penetrating the electrode support at a position on the circumference equidistant from the center of rotation and at equal distance along the circumferential direction,
A through-hole electrode installation member for supporting or fixing the electrode is provided inside the through-hole, and is in contact with the electrode inserted into the through-hole and supported or fixed by the through-hole electrode installation member, and the electrode, charge / discharge device, and electrode evaluation Having an electrode terminal connecting at least one of the devices;
When at least one of the two electrode supports is rotated to form a pseudo cell arrangement and an electrode evaluation cell arrangement, the through holes of each electrode support are connected to form an electrolyte reservoir,
Furthermore, at least one electrode support body has an electrolytic solution filling path for filling the electrolytic solution reservoir with the electrolytic solution, and an electrode performance evaluation apparatus. In the electrode performance evaluation apparatus according to claim 4,
The electrolyte filling path is
An electrolyte solution introduction path for introducing an electrolyte solution formed through the electrode support from the inner disk surface, and an electrolyte solution discharge path for deriving excess electrolyte solution;
An electrolyte circulation groove formed on the inner disk surface, one end of which is connected to the electrolyte introduction through passage, the other through the through hole, and the other end is connected to the electrolyte outlet through passage;
Consisting of
An electrolyte flow path is formed when the disk surface of one electrode support in which the electrolyte groove is formed and the disk surface of the other electrode support are in contact, and at least one of the two electrode supports is rotated. When forming the pseudo cell arrangement and the electrode evaluation cell arrangement, each electrolyte reservoir is filled with the electrolyte through the electrolyte flow path from the electrolyte introduction path, and the excess electrolyte is led out from the electrolyte lead-out path. An electrode performance evaluation apparatus.

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