JP2005197015A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack increasing capacity of a bipolar battery, decreasing internal resistance of the battery, making requested high output and high energy compatible even when the battery pack constituted with bipolar batteries is used as a power source of a vehicle. <P>SOLUTION: The battery pack 1 is constituted by combining in parallel two kinds of batteries of bipolar batteries 3 and usual battery group 7 formed by connecting usual batteries 5 in series by the number of combinations of positive electrodes 13 and negative electrodes 15. The bipolar batteries have detecting tabs 9 connected to each unit cell layer to be constituted, and tab connecting parts 11 every series connection of the usual batteries at the same potential level as the detecting tab are electrically connected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an assembled battery in which two types of batteries, a general battery (a general battery group) in which a bipolar battery and a general battery are connected in series by the number of combinations of positive and negative electrodes of the bipolar battery, are arranged in parallel.

  In general, a bipolar battery generally has a plurality of combinations of positive electrode and negative electrode inside the battery (single cell layer = cell) connected in series, that is, a bipolar structure in which a plurality of combinations of positive electrode and negative electrode exist. (See FIG. 14). In contrast to such a bipolar battery, a general battery generally has a configuration in which a combination of a positive electrode and a negative electrode inside the battery is generally connected in parallel, that is, a bipolar configuration having a single combination of a positive electrode and a negative electrode. A battery having no structure (see FIG. 15).

  In recent years, in order to promote the introduction of electric vehicles (EV), hybrid vehicles (HEV), and fuel cell vehicles (FCV) against the backdrop of an increase in environmental protection movement, these motor drive batteries have been developed. For this purpose, a rechargeable secondary battery is used. In applications that require high output and high energy density, such as EV, HEV, and FCV motor drives, a single large battery cannot be made in practice, and an assembled battery composed of a plurality of batteries connected in series. It was common to use. Moreover, a bipolar secondary battery composed of a plurality of bipolar electrodes has been proposed as one battery constituting such an assembled battery.

As described in the following Patent Documents 1 and 2, the bipolar secondary battery is a battery composed of a plurality of bipolar electrodes, and is thinner, lighter and more radiant than a conventional thin laminated battery. It has various excellent properties such as being good. In particular, the bipolar battery is excellent in output characteristics because it has a configuration in which cells (unit cells) in the battery are connected in series by the bipolar electrode structure.
Japanese Patent Laid-Open No. 2000-1000047 JP 2000-195495 A

  However, when using an assembled battery comprising a plurality of bipolar secondary batteries described in Patent Documents 1 and 2 connected in series as a power source for a vehicle, the output characteristics are sufficient, but the energy characteristics are There was a problem that could not be obtained sufficiently. That is, the performance required for the battery used in the vehicle can be operated, for example, by continuously driving (several hundred W) or peak driving (several KW) of auxiliary devices such as a power window, defogger, and door mirror, or starting the engine at a low temperature ( Several KW), power assault and regeneration at low temperatures, and both high output and high energy are required. While maintaining the performance of either of these, increasing the performance of the other increases the size of the battery, and hence the assembled battery, which is not economical in terms of weight and volume. When the assembled battery is configured using the bipolar secondary battery described in Patent Documents 1 and 2, it is necessary to increase the surface area of the battery to increase the other energy performance while maintaining the output performance. As a result, the battery pack becomes large, and it is not economical in terms of weight and volume. Furthermore, when the surface area of the bipolar secondary battery described in Patent Documents 1 and 2 is increased to increase the capacity, there is a problem that the internal resistance increases.

  Therefore, the present invention has been made to solve the above-described problems of the conventional technology, and even when an assembled battery configured using a bipolar battery is used as a power source for a vehicle. An object of the present invention is to provide an assembled battery that can increase the capacity of a bipolar battery, reduce the internal resistance of the battery, and achieve both the required high output and high energy.

The present invention is an assembled battery in which two types of batteries of a general battery group in which a bipolar battery and a general battery are connected in series by the number of combinations of a positive electrode and a negative electrode of the bipolar battery in parallel structure,
The bipolar battery has a detection tab (hereinafter, also simply referred to as a detection tab) connected to each unit cell layer configured,
This can be achieved by an assembled battery characterized in that a tab connection portion (hereinafter also simply referred to as a general series connection tab) of a general battery having the same potential level as that of the detection tab is electrically coupled.

  In the assembled battery of the present invention, it is possible to efficiently achieve both high output and energy performance by connecting two batteries having different characteristics (bipolar battery + general battery group) in parallel.

  In the assembled battery of the present invention, a detection tab is provided in each single battery layer of the bipolar battery (hereinafter, the single battery layer is also simply referred to as a cell or a battery unit), so that the voltage of each single battery layer is detected and each single battery layer is detected. It is possible to detect the SOC abnormality of the battery layer (see FIGS. 2 to 4).

  Furthermore, in the assembled battery of the present invention, the assembled battery can be stably operated by connecting the detection tab of each single cell layer of the bipolar battery to the general series connection tab of the general battery group having the same voltage level. It becomes.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments of an assembled battery according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic plan view schematically showing a typical embodiment of the assembled battery of the present invention.

  As shown in FIG. 1, the assembled battery 1 of the present invention includes two types of a general battery group 7 in which a bipolar battery 3 and a general battery 5 are connected in series by the number of combinations of the positive and negative electrodes of the bipolar battery 1. An assembled battery 1 having a battery in parallel structure, the bipolar battery 3 having a detection tab 9 connected to each unit cell layer configured, and each series of general batteries having the same potential level as the detection tab 9 The tab connecting portion (general series connecting tab) 11 is electrically coupled.

  In the assembled battery 1 of the present invention having the above-described configuration, a series of general batteries 5 in which a plurality of battery-unit bipolar batteries 3 having a plurality of combinations of positive and negative electrodes and the number of series of the bipolar batteries 3 are the same as the number of battery units of the bipolar battery 3 A battery (general battery group) 7 is connected in parallel. With such a configuration, both ends (+ terminal 13 and −terminal 15) of the bipolar battery 3 and both ends (+ terminal (positive electrode tab) 17 and −terminal (negative electrode tab) 19) of the general battery group 7 have substantially the same voltage. (When the SOC is unified), the assembled battery 1 having both characteristics of the high-power bipolar battery 3 and the high-energy general battery group 7 can be configured (see FIG. 1 and the like). In the bipolar battery 3 having a structure in which the inside of the battery is connected in series, the number of battery units = the number of cells (see FIG. 3) inside the bipolar battery. In the general battery group 7 having a structure in which the general batteries 5 having a structure in which the insides of the batteries are connected in parallel are connected in series, the number of battery units is equal to the number of the general batteries 7 constituting the general battery group.

  Moreover, in the assembled battery 1 of this invention, in order to detect the voltage of each battery unit (= each cell) of the bipolar battery 3 from the outside, it has the structure which takes out the detection tab 9 (refer FIG.1, 2,4). about). This makes it possible to measure the overall voltage of the bipolar battery 3 (voltage between the external terminals 13 and 15) and the SOC of each battery unit (each detection tab 9B to 9L), so that the battery, and hence the assembled battery, can be used stably. become.

  Furthermore, in the assembled battery 1 of the present invention, the general series of the general battery group 7 having the same potential as the potential of each detection tab 9 (9A to 9L) with respect to the external terminal of the bipolar battery 3 (for example, + terminal 13 = detection tab 9M). By electrically connecting the connecting tabs 11 (11B to 11L and further including the electrode tabs 17 and 19 at both ends of the general battery group 7), the potential can be made equipotential. That is, for each battery unit on the side of the bipolar battery 3 where the capacity is small and a small capacity variation may cause a large SOC fluctuation, the capacity of the general battery group 7 is relatively large, and the capacity variation is less likely to occur due to current flow. Each potential is connected, that is, the detection tab 9 (A to M) and the general series connection tab 11 (B to L, further including the electrode tabs 17 and 19) are electrically connected by the connection line 21 (A to M). Thus, it becomes possible for the general battery 5 of the general battery group 7 to suppress the voltage variation of each cell on the bipolar battery 3 side, and the batteries 3 and 5 that can be used stably, and thus the assembled battery 1 can be configured. .

  Here, the same potential level means a potential level at a position where the number of battery units is the same. For example, a bipolar battery 3 having three layers of a single layer 4V battery (= single battery layer; cell) is 4V for the first battery (cell) unit, 8V for the second battery (cell) unit, and three battery (cell) units. Becomes 12V. On the other hand, when 3 general batteries 5 (battery voltage 4V) of the general battery group 7 are connected in series, 4V is obtained for one direct battery (one general battery), 2V (two general batteries are connected in series), 8V, 3 It becomes 12V in series (three general batteries in series). At this time, the positions having the same potential are connected (see FIG. 1). In fact, in a battery whose voltage varies depending on the SOC, for example, the potential of the Li ion battery changes as follows: SOC 0% 2.5V, SOC 100% 4.2V. In this case, connection is performed at the potential level when the SOCs of the general battery group 7 and the bipolar battery 3 are aligned.

  As described in the effect of the invention, the performance required for batteries used in vehicles such as EV, HEV, and FCV is, for example, continuous driving (several hundred W) or peak driving of auxiliary devices such as power windows, defoggers, and door mirrors. (Several KW) can be operated, the engine is started at a low temperature (several KW), power assault and regeneration are performed at a low temperature, and both high output and energy are required. Increasing the other performance while maintaining the performance of either of them increases the size of the battery, which is likely not economical in terms of weight and volume. Therefore, in the present invention, as described above, the bipolar battery 3 which is a battery having two different characteristics and the general battery group 7 are connected in parallel, so that both performances can be efficiently achieved. .

  Among these, in the bipolar battery 3, if only the entire voltage (voltage between terminals 13 and 15) is measured, the voltage (SOC) of each internal layer (= each cell layer 24 = each cell) may vary. For example, as shown in FIG. 3, when a bipolar battery 3 having a single battery unit (one single battery layer) of 4 V and a single battery layer 24 of 10 layers (10 cells) is manufactured, the entire bipolar battery 3 is 40 V. However, even if the individual cell layers 24 inside vary such as 4 V, 3.5 V, 4.5 V, etc., it cannot be determined from the entire voltage alone. However, even if one of the internal cell layers 24 is overcharged or overdischarged, the cell layer becomes unstable as a battery, making it difficult to operate the bipolar battery 3 stably. Therefore, the detection tab 9 is set, the voltage of each cell layer 24 is detected, and the SOC abnormality of each cell layer 24 is detected (see FIGS. 2 to 4).

  Further, in the present invention, the assembled battery 1 is connected by connecting the general series connection tab 11 of the general battery group 7 having the same voltage level to the detection tab 9 of each unit cell layer 24 of the bipolar battery 3 by the connection 21. It becomes possible to operate stably. This point will be described in detail with reference to FIGS. FIG. 5A shows a configuration in which the configuration of the assembled battery in FIG. 1 is simplified, and each layer inside the battery on the bipolar battery side is connected in series, and each general battery on the general battery group side is connected in series. A schematic diagram schematically showing a state in which general series connection tabs for each series of general batteries having the same potential level as the detection tab on the bipolar battery side are electrically coupled together. FIG. 5B is a graph showing changes in the current values on the bipolar battery side and the general battery group side with time transition after large current discharge at the measurement point in FIG. . FIG. 6 (a) shows a general series connection for each series of general batteries at the same potential level as the detection tab on the bipolar battery side in the configuration of the assembled battery of FIG. 5 (a) for comparison with the assembled battery of the present invention. It is the schematic drawing which represented typically a mode that it was set as the assembled battery, without electrically coupling a tab. FIG. 6B is a graph showing changes in current values on the bipolar battery side and the general battery group side with time transition after large current discharge at the measurement point in FIG. 6A. .

  In FIG. 5A, a configuration in which five single battery layers (cells) 24 inside the battery on the bipolar battery 3 side are connected in series, and five general batteries 5 are connected in series on the general battery group 7 side. A general series connection tab (not shown) for each series of the general battery 5 having the same potential level as that of the detection tab (not shown) on the bipolar battery 3 side is electrically connected by the connection line 21 while showing the configuration. . As shown in FIG. 5, for example, when the capacity of each single cell layer 24 in the bipolar battery 3 is 10 mAh and the capacity of the general battery 5 is 1000 mAh, the bipolar battery 3 can be obtained in about 1 hour if a current is passed at 10 mA. Has no capacity, and the SOC becomes 100% → 0%. At this time, if each cell layer 27 has a capacity variation of 10%, in the cell layer 27 that is 10% lower than the capacity average, the SOC is over 100% or 0%, and the battery is in an unstable region. I will enter. On the other hand, in the general battery 5, a capacity of about 990 mAh remains even when a current is passed in the same manner, and the SOC hardly shifts. Here, when the bipolar battery 3 and the general battery 5 are connected in parallel, the potentials at both ends of both batteries become equal, so the SOC of the bipolar battery 3 moves toward the SOC of the general battery 5 having a large capacity. A wide SOC range can be maintained (see FIG. 5B). This point will be described with reference to FIG. 5B. The discharge time 0 is immediately after the assembled battery 1 finishes the large current discharge, and there is no capacity remaining on the bipolar battery 3 side. When time elapses from A to A after the large current discharge, a current flows from the general battery 5 having a large capacity into the bipolar battery 3. The point is that the current value temporarily becomes zero when time elapses from B to B after the large current discharge. When time elapses from C to C after the large current discharge, a part of the current flows backward from the bipolar battery 3 to the general battery 5. After the point of time after the large current discharge until D, the bipolar battery 3 and the general battery 5 are in a state of stable current (current value becomes 0).

  Further, in the assembled battery 1 of the present invention, when the SOC control of the general battery group 7 is not sufficient, the structure of the present invention is further controlled by controlling the voltage / SOC in a circuit by using an external circuit. However, it is not particularly limited.

  On the other hand, as shown in FIG. 6A, only the parallel structure of the bipolar battery 3 and the general battery group 7 may enter an unstable SOC region due to variations in capacity on the bipolar battery 3 side. This point will be described with reference to FIG. 6B. The discharge time 0 is immediately after the assembled battery 1 finishes the large current discharge, and there is no capacity remaining on the bipolar battery 3 side. When time elapses from A to A after the large current discharge, a current flows from the general battery 5 having a large capacity into the bipolar battery 3. The point is that the current value temporarily becomes 0 when time elapses from B to B after the large current discharge (the process up to this point is the same as in FIG. 5B). Thereafter, when time elapses from C to C after the large current discharge, the current value is temporarily reversed before the bipolar battery 3 and the general battery 5 are stabilized in terms of current. After this, it will stabilize, but it takes a long time for the connection specification of FIG. That is, the overcharge state continues for a long time on the bipolar battery 3 side. Therefore, there is a possibility of entering an unstable SOC region due to the variation in capacity on the bipolar battery 3 side.

  In the assembled battery of the present invention, each of the cross-sectional areas of the positive electrode tab 13 and the negative electrode tab 15 of the bipolar battery 3 is at least twice the cross-sectional area of the connection 21 between the detection tab 9 and the connection tab 11 of each general battery in series. It is desirable to have the above. This is because the positive electrode tab 13 and the negative electrode tab 15 of the bipolar battery 3 need to be enlarged to such an extent that heat generation or the like does not pose a problem even when a large current flows when a high-power bipolar battery 3 is used. 9 and the connection 21 of the general series connection tab 11 basically do not allow a large current to flow (there is no need to flow a large current), and therefore it is not necessary to increase the cross-sectional area. Moreover, when the cross-sectional area of the connection line 21 is increased, the connection line connection 21 is increased, and the merit is reduced in terms of battery weight and volume. Moreover, if the cross-sectional area of the connection 21 is large, the resistance is small and the current easily flows. However, if a very large current flows from the detection tab 9, the variation of each cell layer 27 (see FIG. 3) of the bipolar battery 3. On the other hand, there is a possibility that becomes larger. Therefore, the cross-sectional areas of the positive electrode tab 13 and the negative electrode tab 15 are preferably at least twice the cross-sectional area of the connection line 21 (one). Furthermore, more than twice the total cross-sectional area of each connection 21 is more desirable.

  Moreover, in the assembled battery of this invention, it is desirable for the electrode tabs of the general battery 5 to be joined by vibration welding. That is, it is desirable that the tab connection portions (general series connection tabs) 11 for each series of the general batteries 5 are joined by vibration welding (connection method when the general batteries 5 are connected in series). This is because the connection resistance of the tab is generally low. Further, the vibration welding is performed on the tab surface with a plurality of spots, so that there is an advantage that the rigidity of the joint portion is increased and the rigidity of the general battery group is increased. Furthermore, in vibration welding, the temperature rise at the time of joining is smaller than in normal spot welding, and the influence on the sealing portion of the battery element material (electrode active material, separator, electrolyte, etc.) and battery exterior material can be suppressed. In addition, variation in connection resistance is smaller than in rivet bonding. However, the present invention is not limited to these, and in order to join and connect the electrode tabs of the general battery 5, in addition to vibration welding (ultrasonic welding), thermal welding, laser welding, or electron beam welding. Can also be used. Further, the tabs of the general battery 5 may be joined in series, as shown in FIG. 1. Depending on the arrangement, a bus bar 12 such as a rivet may be used, or a caulking method may be used. Can be used. Further, when the bus bar 12 and the tab of the general battery 5 are connected, not only vibration welding (ultrasonic welding) but also heat welding, laser welding, or electron beam welding may be used.

  Similarly, the detection tab 9 of the bipolar battery 3 (including the electrode tabs 13 and 15 also serving as the detection tabs 9M and 9A) and the general series connection tab 11 (11B to 11L, and the electrode tabs 17 and 19 at both ends of the general battery group 7 are also included. In addition, vibration welding (ultrasonic welding), thermal welding, laser welding, or electron beam welding can also be used. Further, there is no particular limitation such that a caulking method can be used.

  Moreover, it is desirable that the resistance of all the connections 21 (A to M) of the detection tab 9 and the general series connection tab 11 is in the range of + 30% to −30% with respect to the average value of the whole. This is because if the resistance of the connection line 21 is different, the capacity variation of each single cell layer 27 of the bipolar battery 3 is likely to increase. Furthermore, it is desirable that each connection resistance is in the range of + 30% to −30% with respect to the average value of the resistance of the connection 21. This is because, within this range, there are few problems even if there are variations in capacity. Further, since this width is determined by the life of the stable operation of the battery, it is desirable that the width is small. Preferably, it exists in + 10%--10%.

  Moreover, in the assembled battery of this invention, the Young's modulus of the material of all the connections 21 (A-M) of the detection tab 9 and the general series connection tab 11 is equal to or less than the material of the detection tab 9 and the general series connection tab 11. It is desirable. The assembled battery 1 in which the bipolar battery 3 and the general battery group 7 are connected in parallel is an assembled battery integrated by the connection 21, and therefore may be easily affected by vibration. Therefore, in order for the tabs 9 and 11 and the connection 21 themselves to be vibration resistant, the Young's modulus of the tabs 9 and 11 and the connection 21 are close to each other, or the Young's modulus of the tabs 9 and 11 is It is appropriate that it is larger than that of the connection 21. If the Young's modulus is close, the whole will be rigidly integrated and suitable. When the Young's modulus of the connection 21 is small, the entire bipolar battery 3 and the entire general battery group 7 are integrated, and the vibration of the connection portion as a node can be prevented and the joint portion of the tab portion that is vulnerable to vibration can be prevented from shaking.

  As a material satisfying the Young's modulus requirement, the detection tab 9 of the bipolar battery 3 is a clad material of SUS (200 GPa), Ti (110 GPa), copper and aluminum when it is composed of a Li ion battery. In the case of the general battery 5, since the positive electrode tab 17 is Al (70 GPa) and the negative electrode tab 19 is Ni (200 GPa), Cu (130 GPa), the general series connection tab 11 (positive electrode tab 17 + negative electrode tab 19) Made of material. Therefore, it is desirable to use Al wire, Cu wire, or iron (110 Gpa) wire as the connection 21. However, the present invention is not limited to these. In addition, when using the bus bar 12 for the tab connection part for every series of the general battery 5, as a material of the bus bar 12 which satisfies the requirements for the Young's modulus, copper, aluminum, or the like is used. This is because the connection 21 (I) may be joined to the bus bar 12 in the general serial connection tab 11 (I) of FIG.

  The schematic diagram of the connection between the detection tab 3 and the general serial connection tab 11 is shown in FIGS. FIG. 1 is as described above. FIG. 8 is a schematic plan view schematically showing another exemplary embodiment of the assembled battery of the present invention.

  Also in the assembled battery 1 of the present invention shown in FIG. 8, two types of batteries of the general battery group 7 in which the bipolar battery 3 and the general battery 5 are connected in series by the number of combinations of the positive electrode and the negative electrode of the bipolar battery 1 are connected in parallel. An assembled battery 1 having a structure, wherein the bipolar battery 3 has a detection tab 9 connected to each unit cell layer, and a tab for each series of general batteries 5 having the same potential level as the detection tab 9 The connection part (general series connection tab) 11 is electrically coupled. The difference in the configuration of the assembled battery of FIG. 1 is that in FIG. 8, the electrode tabs 13 and 15 of the bipolar battery 3 are both taken out from the upper side of the battery, and the general battery 5 constituting the general battery group 7 is removed. The same number (8) is arranged on both the left and right sides. Therefore, in the bipolar battery 3, the detection tab 9 is similarly taken out from both the left and right sides of the bipolar battery 3.

  As shown in FIG. 8, it is desirable that the connections 21 have the same length as much as possible and are wired so that the distance between the bipolar battery 3 and the general battery group 7 is not separated. Moreover, not a lead wire but a metal plate may be used. The wiring diagram is not limited to this embodiment, and wiring different from these may be used as long as the above object is satisfied. Similarly, the tab connection part (general series connection tab) 11 for each series of the general battery 5 only needs to be electrically coupled, and the electrode tabs of the general battery 5 are directly joined to each other as used in FIG. Alternatively, a bus bar 12 such as a metal plate or a rivet may be used. Further, as shown in FIG. 8, the wires may be electrically coupled by a connection such as a lead wire (for example, refer to the general serial connection tab 11 </ b> B). In the present invention, the tab connection portion for each series of the general battery 5 by connection such as a lead wire is referred to as a general series connection tab.

  Next, in the battery pack of the present invention, the distance between the center of gravity on the surface of the bipolar battery and the center of gravity of the projected outline of the general battery group is the short side length and the short side length of the short side of the bipolar battery or the general battery group outline. It is desirable to be within this range (except that at least a part of the general battery group overlaps the surface of the bipolar battery).

  7 shows that the distance between the center of gravity on the surface of the bipolar battery and the center of gravity of the projected outline of the general battery group is the same as that of the assembled battery of FIG. It is the schematic plan view which represented typically the embodiment of the vibration proof structure arrange | positioned so that it might become the range of length. Therefore, since the configuration itself is the same as that of the assembled battery in FIG. 1, description other than the requirement for the distance between the centers of gravity is omitted. In addition, the reference numerals in the figure are also the same as those in FIG. 8 and 9, the configuration of the assembled battery in FIG. 1 is basically the same and only the arrangement of the tabs and the general battery group is different. Therefore, the description other than the requirement for the distance between the centers of gravity is omitted. . In addition, the reference numerals in the figure are the same as those in FIG. 1 and are not particularly necessary to explain the requirement for the distance between the centers of gravity, and therefore, part of the reference numerals are omitted.

In Figure 7, the battery pack 1 of FIG. 1, the center of gravity G ₁ on the bipolar battery 3 surface, the distance L between the center of gravity G ₂ of the projection outline of the general cell group 7, the bipolar battery 3 or the general cell group 7 outline the long and short side length L ₁ of the short sides are arranged such that the short short side of length L ₂ range. That is, in FIG. 7, the distance L between the center of gravity G ₂ of the center of gravity G ₁ and the general group of batteries 7 of the bipolar battery 3, the short side of the bipolar battery 3: short side (FIG. (FIG. 7 long and short sides) and general cell group 7: short short side). By doing so, the distance L between the bipolar battery 3 and the general battery group 7 can be made as small as possible and integrated to increase the rigidity of the entire assembled battery and to impart resistance to vibration. FIG. 10 shows vibrations of the assembled battery (invention structure) having the connection of FIG. 7 and the assembled battery (conventional structure) in which the detection tab and the general series connection tab are not electrically coupled (no connection) in the assembled battery of FIG. The state of is shown. As shown in FIG. 10, when there is no connection, the entire assembled battery is not rigid, so a large peak is seen in the vibration transmissibility, but when there is a connection, the assembled battery is given rigidity and the center of gravity position is From the closeness, it can be seen that the anti-vibration effect is exhibited, and the vibration level of the peak and remnant is lowered. Note that the vibration test of the assembled battery in FIG. 10 measures how the assembled battery vibrates due to the vibration received from the vehicle when the assembled battery according to the present invention is mounted on the vehicle, and the frequency-vibration transmissibility. It represents the characteristics of This measuring method will be described in the examples described later.

On the other hand, it is also desirable to arrange the general battery group 7 on both sides of the bipolar battery 3 as in the assembled battery of FIG. Specifically, the center of gravity G ₁ on the bipolar battery 3 surface, the distance La between the center of gravity G ₂ of the projection outline of the general cell group 7a which is separately arranged on the right side of the bipolar battery 3, the bipolar battery 3 or the general cell group 7a contour long and short side length L ₁ short side of the are arranged such that the short short side of length L ₂ range. Similarly, the center of gravity G ₁ on the bipolar battery 3 surface, the distance Lb between the center of gravity G ₃ of the projection outline of the general cell group 7b which are separately arranged on the left side of the bipolar battery 3, the bipolar battery 3 or the general cell group 7b contour The short side is arranged so as to fall within the range of the short short side length L ₁ and the short short side length L ₃ . That is, in FIG. 8, the distances La and Lb between the center of gravity G ₁ of the bipolar battery 3 and the centers of gravity G ₂ and G _{3 of the} general battery group 7 are the same as the short side of the bipolar battery 3 (FIG. 8: long and short side L ₁ ). It is made to fall within the range of the length of the short side of the battery group (FIG. 8: short short side L ₂ , L ₃ ). In this case, since the centroids G ₂ and G ₃ exist in the two general battery groups 7, the above-described requirements are satisfied at the distances La and Lb between the centroids G ₁ and G _{2 and} between the centroids G ₁ and G _3. , L ₂ <La <L ₁ and L ₃ <Lb <L ₁ are preferably satisfied. This is because, by setting the entire assembled battery 1 as the target arrangement in this way, the balance of the entire assembled battery 1 is improved, and it is possible to prevent a vibration change.

  Furthermore, in the assembled battery of the present invention, it is desirable that at least a part of the general battery group overlaps on the surface of the bipolar battery. In this case, the distance between the center of gravity on the surface of the bipolar battery and the center of gravity of the projected outer shape of the general battery group is preferably shorter than the long and short side length of the short side of the outer shape of the bipolar battery or the general battery group. It is more desirable that the length is shorter than the short short side length of the general battery group outer shape.

FIG. 9 shows an embodiment of the assembled battery in which the projected area of the battery is reduced by folding the assembled battery of FIG. 8 at the dotted line portion so as to overlap the bipolar battery. It is the schematic plan view which represented the mode before superimposing a general battery group on. In this method, since the distances La and Lb between the centroids G ₁ and G ₂ and the centroids G ₁ and G ₃ between the bipolar battery 3 and the general battery groups 7a and 7b are particularly small, the rigidity of the assembled battery 1 is improved. Excellent vibration isolation. 9, by bending in dotted lines, the center of gravity _{G 1} on the bipolar battery 3 surface, the general cell groups 7a, 7b of the projection contour of the center of gravity _G 2, the distance between _{G 3} La, Lb is, La <L ₂ <L ₁ and Lb <L ₃ <L _{1 and} can be shorter than the short side lengths L ₂ and L ₃ .

  In FIG. 9, it is desirable to select the material of the wiring 21 so that the assembled battery of FIG. 8 may be bent at the dotted line portion. This is because if the strength is too high, there is a risk of damage due to bending or subsequent vibration.

The center of gravity G ₁ , G ₂ , G ₃ is based on the projected outer shapes S ₁ , S ₂ , S ₃ formed including the battery electrode tab and the detection tab, as shown in FIGS. .

As shown in FIGS. 7 to 9, it is desirable to arrange the centers of gravity G ₁ , G ₂ , G ₃ in the long side direction of the battery so that they are on the horizontal line (on a straight line).

The short side length of the outer shape of the bipolar battery 3 or the general battery group 7 is the length of the shorter side of the shorter side of the bipolar battery 3 and the outer side of the general battery group 7. . Conversely, the short short side length of the outer shape of the bipolar battery 3 or the general battery group 7 here is the shorter short side of the short side of the bipolar battery 3 and the short side of the general battery group 7 outer shape. The length of In Figure 7, towards the length of the short side of the bipolar battery 3 is longer than the length of the short side of the common cell group 7 outline, the length of the short side of the bipolar battery 3 becomes long and short side length L _1. The length of the short side of the common cell group 7 contour is shorter short side length L _2. However, when the general battery group 7 is divided into two or more (see FIGS. 8 and 9), the center of gravity of the projected outline of the general battery group 7 for each divided general battery group 7 (see FIG. 8, 9: G ₂ , G ₃ ) and the length of the short side of the outer shape of the general battery group 7 are not long or short side lengths (FIG. 8, 9: L ₂ , L ₃ ). Become.

  The planar shape of the bipolar secondary battery 3 exemplified in the above embodiment is a rectangle, and the positive electrode tab 13 and the negative electrode tab 15 connected to the power generation element (battery body) 2 are separated from each of two opposite sides of the rectangle. The case where it is pulled out is shown. However, in the present invention, the positive electrode tab and the negative electrode tab may be drawn in parallel from only one side of the rectangular battery, or may be drawn separately from each of the two adjacent sides of the rectangular battery. There is no particular limitation such as good.

  Hereinafter, as a typical embodiment of a bipolar battery that can be used in the present invention, a bipolar secondary battery (referred to as Embodiment 1) in which a positive electrode tab 13 and a negative electrode tab 15 are drawn from different sides, and a positive electrode Embodiments of a bipolar secondary battery (referred to as Embodiment 2) in which the tab 13 and the negative electrode tab 15 are drawn from the same side will be described with reference to the drawings.

(1) Bipolar Secondary Battery of Embodiment 1 FIG. 2 is an external view of a bipolar secondary battery according to the present embodiment, (a) is a front view thereof, (b) is a side view thereof, (c). Shows a cross-sectional view along the line AA. FIG. 3 is a schematic cross-sectional view of the inside of the battery schematically illustrating the internal structure and the tab connection structure of the bipolar secondary battery of FIG. FIG. 2 shows an example in which the voltage detection tab of the bipolar battery is drawn out only from the right side, and FIG. 3 shows an example in which the voltage detection tab of the bipolar battery is drawn out from both the left and right sides.

  As shown in FIG. 2, the bipolar secondary battery 3 includes a power generation element (battery body) 2 therein, and the power generation element 2 includes a positive electrode tab 13, a negative electrode tab 15, and a voltage detection tab 9 ( 9B to 9J) are connected. The power generation element 2 is a rectangular parallelepiped three-dimensional solid having a rectangular shape when viewed from the front. The power generation element 2 is sandwiched from above and below by two rectangular polymer metal composite films 22 such as a laminate film, and the periphery thereof is heat-sealed and sealed. The positive electrode tab 13, the negative electrode tab 15, and the voltage detection tab 9 are exposed to the outside from the polymer metal composite film 22. The cross section of the portion where the negative electrode tab 15 is pulled out from the polymer metal composite film 22 is as shown in FIG. 2C, and the polymer metal composite film 22 is surrounded by the periphery of the negative electrode tab 15 at the sealing portion 23. It is in close contact with the water and prevents moisture from entering.

  As illustrated, the positive electrode tab 13 and the negative electrode tab 15 are drawn from two opposite sides of the bipolar secondary battery 3 having a rectangular shape. That is, the positive electrode tab 13 is pulled out from one side (upper side) of the rectangle, and the negative electrode tab 15 is pulled out from one side (lower side) opposite to the side from which the positive electrode tab 13 is pulled out.

  Further, the voltage detection tab 9 is drawn from a different direction from the positive electrode tab 13 and the negative electrode tab 15 as shown in the figure. That is, the voltage detection tab 9 is drawn out from the side other than the side from which the positive electrode tab 13 and the negative electrode tab 15 are drawn. As described above, the positive electrode tab 13 and the negative electrode tab 15 which are electrode tabs and the voltage detection tab 9 are convenient to be taken out from different sides of the battery for convenience such as wiring, and the airtightness of the seal portion is ensured. This is also desirable from a viewpoint.

  The thickness of each voltage detection tab 9 is determined so that the total cross-sectional area of the voltage detection tab 9 is equal to or less than the total cross-sectional area of the positive electrode tab 13 and the negative electrode tab 15. The cross-sectional area of the voltage detection tab 9 is determined by the relationship between the positive electrode tab 13 and the negative electrode tab 15 when the bipolar secondary battery 3 is fixed when these tabs are fixedly attached to the vehicle-side electrode. This is mainly because the positive electrode tab 13 and the negative electrode tab 15 are supported, and the bipolar secondary battery 3 is supported in an auxiliary manner by the voltage detection tab 9. By doing so, an excessive load is not applied to the voltage detection tab 9 which is less rigid than the positive electrode tab 13 and the negative electrode tab 15, and the tab is not torn due to vibration. This is because sufficient reliability can be maintained.

  The number of voltage detection tabs 9 drawn out from each side of the polymer metal composite film 25 is distributed according to the number of sides from which the voltage detection tabs 9 are drawn out and the lengths of the sides. In the case of the bipolar battery 3 shown in FIG. 2, the voltage detection tab 9 is pulled out only from the right side. The arrangement interval of the voltage detection tabs 9 is narrower than the width thereof. However, in the present invention, the width of each voltage detection tab 9 and the arrangement interval of each voltage detection tab 9 may be made equal.

  The voltage detection tab 9 can detect the voltage between terminals of all the cell layers 24-1 to -10 (see FIG. 3).

  In the case of the bipolar secondary battery 3 of the first embodiment, since the general battery group 7 is all arranged on the right side of the bipolar battery 3, the voltage detection tab 9 is arranged on one side (right side) so that the wiring 21 can be easily wired. Only pulls from.

  On the other hand, when the general battery group 7 is arranged separately on both sides of the bipolar battery 3 as shown in FIGS. 8 and 9, which will be described later, the voltage detection tab 9 can be pulled out from the left and right sides as shown in FIG. I can say that. Such an arrangement is excellent in terms of the vibration suppression effect of the assembled battery, as will be described later.

  In particular, when the number of voltage detection tabs 9 is pulled out from both the left and right sides of the bipolar battery 3 and the width of each voltage detection tab 9 is equal to the arrangement interval of the voltage detection tabs 9, the bipolar secondary battery 3 is balanced. It will be able to support well, and the voltage detection tab 9 will not be overburdened and will not break the tab due to vibration, so that it can maintain sufficient reliability even when mounted on the vehicle become able to. Further, when the arrangement intervals of the voltage detection tabs 9 are equal, a short circuit between the tabs can be prevented, and a socket for connecting the tabs can be easily attached.

  FIG. 3 is a diagram showing an internal configuration of the power generation element 2 inside the bipolar secondary battery 3 and a connection state of the positive electrode tab 13, the negative electrode tab 15, and the voltage detection tab 9 in the power generation element 2.

  As shown in the figure, the power generating element 2 has nine bipolar electrodes 28 in which the positive electrode layer 26 is formed on one surface of the current collector 25 (25B to 25J) and the negative electrode layer 27 is formed on the other surface. Is provided. In addition, only one electrode layer of the positive electrode layer 26A and the negative electrode layer 27K is formed on the current collectors 25A and 25K located at both ends of the power generation element 2 in the stacking direction. These bipolar electrodes 28 are laminated such that the positive electrode layer 26 and the negative electrode layer 27 of the adjacent bipolar electrodes 28 face each other, and an electrolyte layer 29 is interposed between the bipolar electrodes 28.

  In the present embodiment, the two power collectors 25A and 25K having only nine bipolar electrodes 28, the positive electrode layer 26A or the negative electrode layer 27K are stacked as shown in the drawing to form the power generating element 2 as shown in the figure. Forming. Accordingly, the cell layers 24-1 to -10 are formed between the two current collectors 25. In this embodiment, since the voltage between the terminals of the single cell layer is 4.2V, the voltage between the terminals of the power generation element 2 is 42V. In the bipolar secondary battery 3, the voltage between terminals of a single cell layer per one does not use a bipolar electrode, for example, a general secondary battery such as a lithium ion secondary battery (that is, a general battery 5). Since it is higher than the inter-terminal voltage, a high-voltage battery can be easily constructed.

  A negative electrode tab 15 and a positive electrode tab 13 are connected to current collectors 25A and 25K located at both ends of the power generation element 2 in the stacking direction, respectively. The positive electrode tab 13 and the negative electrode tab 15 are connected to a vehicle load (motor, electrical component, etc.) not shown, and a very large charge / discharge current flows through these tabs 13 and 15. Moreover, the voltage detection tab 9 (9A-9K) for detecting the voltage between the terminals of a cell layer is connected to all the current collectors (11 pieces) provided in the power generation element 2. The width and thickness (in other words, the cross-sectional area) of the positive electrode tab 13 and the negative electrode tab 15 are mainly determined by the current value at the time of charging / discharging that will flow through it. On the other hand, the width and thickness of the voltage detection tab 9 are determined mainly from the viewpoint of suppressing the vibration of the bipolar secondary battery 3 (in other words, from the viewpoint of compensating for insufficient rigidity by the positive electrode tab 13 and the negative electrode tab 15).

  In FIG. 3, the voltage detection tab 9 is divided into two sides of the power generation element 2, and the current collector located in the middle of the battery element 2 is made possible to detect the voltage between terminals of all the single battery layers. The body 25F is connected with two voltage detection tabs 9F drawn out on opposite sides. Therefore, it is possible to detect the voltage between the terminals of the cell layers 24-1 to -10 in FIG.

  Further, as shown in FIG. 3, the voltage detection tab 9 is drawn out in the longitudinal direction of the side of the power generation element 2 in the order in which the bipolar electrodes 28 are stacked. That is, the voltage detection connected to the current collector 25F located in the middle from the voltage detection tab 9A connected to the current collector 25A located at the bottom of the power generation element 2 on the right side of the power generation element 2 The tabs 9F are arranged in order and pulled out, and on the left side of the power generation element 2, the voltage detection tab 9F connected to the current collector 25F located in the middle of the power generation element 2 is the uppermost current collector. The voltage detection tabs 9K connected to the electric body 25K are arranged in order and pulled out.

  Thus, when the voltage detection tabs 9A to 9K are aligned and pulled out, the sealing performance of the sealing portion of each voltage detection tab 9 is improved, and the reliability of the bipolar secondary battery 3 is improved. In addition, the bipolar secondary battery 3 can be supported in a well-balanced manner, so that an excessive load is not applied to the voltage detection tab 9 and the tab is not torn due to vibration. Reliable.

  Furthermore, in the bipolar secondary battery according to the present embodiment, the number of voltage detection tabs 9 is different from that in FIGS. In the bipolar secondary battery 3 of FIG. 2, nine voltage detection tabs 9 (9B to 9J) are drawn from the right side of the battery. In the bipolar secondary battery 3 of FIG. 3, six voltage detection tabs 9 (9A to 9F, 9F to 9K) are drawn from the left and right sides of the battery, respectively. In FIG. 2, the voltage detection tabs 9 are current collectors (current collectors in FIG. 3) other than current collectors (corresponding to the current collectors 25 </ b> A and 25 </ b> K in FIG. 3) located at both ends of the power generation element 2 in the stacking direction. 25B to 25J). Therefore, in the case of the bipolar secondary battery 3 shown in FIG. 2, it is possible to detect the voltage between the terminals of the single battery layers 24-2 to -9 shown in FIG. As described above with reference to FIG. 3, the inter-terminal voltages of all the cell layers 24-1 to -10 can be detected. However, as shown in FIG. 1, if the voltage detection tab 9 is connected to a current collector other than the current collector located at both ends in the stacking direction of the power generating element 2, the corresponding general battery group 7 is connected in a general series. Since the connection tab 11 can be electrically coupled, the effects of the present invention can be effectively expressed.

(2) Bipolar Secondary Battery of Embodiment 2 FIG. 4 is an external view of a bipolar secondary battery of the type according to this embodiment, where (a) is a front view, (b) is a side view thereof, ( c) shows a cross-sectional view taken along the line AA.

  As shown in the figure, the bipolar secondary battery 3 includes a power generation element 2 (see FIG. 3) therein. The power generation element 2 includes a positive electrode tab 13, a negative electrode tab 15, and a voltage detection tab 9 ( 19A to 9K) are connected. The power generation element 2 is a rectangular parallelepiped three-dimensional solid having a rectangular shape when viewed from the front. The power generation element 2 is sandwiched from above and below by two rectangular polymer metal composite films 22 such as a laminate film, and the periphery thereof is heat-sealed and sealed. The positive electrode tab 13, the negative electrode tab 15, and the voltage detection tab 9 are exposed to the outside from the polymer metal composite film 23. The cross section of the portion where the negative electrode tab 15 is pulled out from the polymer metal composite film 22 is as shown in FIG. 4C, and the polymer metal composite film 22 is connected to the positive electrode tab 13 and the negative electrode at the sealing portion 23. It adheres to the periphery of the tab 15 to prevent moisture from entering from the outside.

  As illustrated, the positive electrode tab 13 and the negative electrode tab 15 are drawn from the same side of the bipolar secondary battery 3 having a rectangular shape. That is, the positive electrode tab 13 and the negative electrode tab 15 are drawn from one side (upper side) of the rectangle.

  Further, the voltage detection tab 9 is drawn from a different direction from the positive electrode tab 13 and the negative electrode tab 15 as shown in the figure. That is, the voltage detection tab 9 is drawn out from two sides other than the side from which the positive electrode tab 13 and the negative electrode tab 15 are drawn.

  The thickness of each voltage detection tab 9 is determined so that the total cross-sectional area of the voltage detection tab 9 is equal to or less than the total cross-sectional area of the positive electrode tab 13 and the negative electrode tab 15 as in the first embodiment.

  The number of voltage detection tabs 9 drawn out from each side of the polymer metal composite film 22 is distributed according to the number of sides from which the voltage detection tabs 9 are drawn out and the lengths of the sides. In FIG. 4, six voltage detection tabs 9 (9A to 9F) are drawn from the right side of the bipolar secondary battery 3, and six voltage detection tabs 9 (9F to 9K) are also drawn from the left side. Further, the voltage detection tabs 9 drawn from the left and right sides have the same width of the voltage detection tabs 9 and the arrangement interval of the voltage detection tabs 9.

  When the number of voltage detection tabs 9 is pulled out equally, and the width of each voltage detection tab 18 is equal to the arrangement interval of each voltage detection tab 9, the bipolar secondary battery 3 can be supported in a balanced manner. In addition, an excessive burden is not applied to the voltage detection tab 9 and the possibility of the tab tearing due to vibration is reduced, so that sufficient reliability can be ensured even when mounted on a vehicle with much vibration. become.

  Since the structure of the power generation element 2 and the connection state of the positive electrode tab 13, the negative electrode tab 15, and the voltage detection tab 9 in the power generation element 2 are the same as those in the first embodiment, description thereof will be omitted.

  However, the present embodiment is not limited to these. For example, the voltage detection tab may be pulled out from only one side other than the extraction side of the electrode tabs 13 and 15, or the battery It differs in that it consists of three sides.

  In the case of this type of bipolar secondary battery 3, compared with the bipolar secondary battery 3 having the configuration shown in FIG. 7, since the voltage detection tab 9 is pulled out from only one side, the rigidity against vibration cannot be denied. . However, the decrease can be suppressed to some extent by adjusting the width and thickness of each voltage detection tab 9.

  The bipolar secondary battery according to the present invention has been described above in two embodiments, but each component of the bipolar secondary battery of the present invention can be configured using the following materials. Similarly, each component of the general battery of the present invention can also be configured using the following materials. That is, the bipolar secondary battery and the general battery of the present invention basically differ only in whether the single cell layers inside the battery are connected in series or in parallel, and each component constituting the battery is different. Are not particularly different. Therefore, in the following description, configurations of a general battery and a bipolar battery that can be used in the present invention will be briefly described with reference to the drawings. However, the present invention should not be limited to these. FIG. 14 is a schematic cross-sectional view schematically showing the entire structure of a typical general battery. FIG. 15 is a schematic sectional view schematically showing the entire structure of a typical bipolar battery.

  FIG. 14 is a schematic cross-sectional view of a flat type (stacked type) non-aqueous electrolyte lithium ion secondary battery that is not a bipolar type, which is a typical general battery. In the lithium ion secondary battery 31 shown in FIG. 14, a positive electrode current collector is obtained by joining all of the peripheral part by thermal fusion using a laminate film in which a polymer-metal is combined with the battery exterior material 32. A negative electrode active material layer 37 is formed on both surfaces of the positive electrode plate having the positive electrode active material layer 34 formed on both surfaces of the electrode 33, the electrolyte layer 35, and the negative electrode current collector 36 (one side for the lowermost layer and the uppermost layer of the power generation element). In addition, the power generation element 38 in which the negative electrode plates are stacked is housed and sealed. Further, the positive electrode (terminal) lead 39 and the negative electrode (terminal) lead 40 that are electrically connected to the positive electrode plate and the negative electrode plate described above are connected to the positive electrode current collector 33 and the negative electrode current collector 36 of each electrode plate by ultrasonic welding or resistance. It has a structure that is attached by welding or the like and is exposed to the outside of the battery outer packaging material 32 by being sandwiched between the heat fusion portions.

  FIG. 15 is a schematic cross-sectional view schematically showing the entire structure of a bipolar non-aqueous electrolyte lithium ion secondary battery (hereinafter also simply referred to as a bipolar battery), which is a typical bipolar battery. As shown in FIG. 15, in the bipolar battery 41, a positive electrode active material layer 43 is provided on one side of a current collector 42 composed of one or more sheets, and the negative electrode active material layer of the present invention is provided on the other side. The positive electrode active material 43 and the negative electrode active material layer 44 of the bipolar electrode 45 adjacent to each other with the electrolyte layer 46 sandwiched between the bipolar electrode 45 provided with 44 are opposed to each other. That is, in the bipolar battery 41, a plurality of bipolar electrodes 45 having the positive electrode active material layer 43 on one surface of the current collector 42 and the negative electrode active material layer 44 on the other surface are disposed via the electrolyte layer 46. The electrode laminate (bipolar battery main body) 47 has a laminated structure. Further, the uppermost layer and the lowermost layer electrodes 45a and 45b of the electrode laminate 47 in which a plurality of such bipolar electrodes 45 and the like are laminated may not have a bipolar electrode structure, and are necessary for the current collector 42 (or terminal plate). A structure in which the positive electrode active material layer 43 or the negative electrode active material layer 44 only on one side may be arranged. In the bipolar battery 41, positive and negative electrode leads 48 and 49 are joined to current collectors 42 at both upper and lower ends, respectively.

  Note that the number of stacked bipolar electrodes 45 (including the electrodes 45a and 45b) is adjusted according to a desired voltage. Further, in the bipolar battery 41, the number of lamination of the bipolar electrode 45 may be reduced if a sufficient output can be secured even if the battery is made as thin as possible. Further, in the bipolar battery 41 of the present invention, in order to prevent external impact and environmental degradation during use, the electrode laminate 47 portion is sealed under reduced pressure in a battery exterior material (exterior package) 50, and electrode leads 48, It is preferable that 49 be taken out of the battery exterior material 50. The basic configuration of the bipolar battery 41 can be said to be a configuration in which a plurality of stacked single battery layers (single cells) are connected in series. Since this bipolar battery is basically the same as the above-described general battery except that the electrode structure is different, each component common to the bipolar secondary battery and the general battery of the present invention will be described below. The components will be described together by taking a lithium ion secondary battery as an example. However, the bipolar secondary battery and the general battery of the present invention are not only lithium ion secondary batteries but also sodium ion secondary batteries and potassium ion secondary batteries when viewed with electrode materials or metal ions moving between the electrodes. The present invention is not particularly limited, for example, applicable to nickel hydride secondary batteries, nickel cadmium secondary batteries, and the like.

[Current collector]
The current collector is not particularly limited, and a conventionally known one can be used. For example, aluminum foil, stainless steel (SUS) foil, titanium foil, nickel-aluminum clad material, copper-aluminum clad material, SUS-aluminum clad material, or a plating material of a combination of these metals can be preferably used. Further, a current collector in which a metal surface is coated with aluminum may be used. Moreover, you may use the electrical power collector which bonded 2 or more metal foil depending on the case. When the composite current collector is used, as a material for the positive electrode current collector, for example, a conductive metal such as aluminum, an aluminum alloy, SUS, or titanium can be used, and aluminum is particularly preferable. On the other hand, as the material of the negative electrode current collector, for example, conductive metals such as copper, nickel, silver, and SUS can be used, and SUS and nickel are particularly preferable. Further, in the composite current collector, the positive electrode current collector and the negative electrode current collector may be electrically connected to each other directly or via a conductive intermediate layer made of a third material.

  Each thickness of the positive electrode current collector and the negative electrode current collector in the composite current collector may be as usual, and both current collectors are, for example, about 1 to 100 μm. The thickness of the current collector (including the composite current collector) is preferably about 1 to 100 μm from the viewpoint of thinning the battery.

[Positive electrode layer (positive electrode active material layer)]
As a constituent material of the positive electrode layer, any material containing a positive electrode active material may be used. If necessary, a conductive additive for increasing electronic conductivity, a binder, and an electrolyte supporting salt for increasing ionic conductivity ( Lithium salt), polymer electrolytes, additives, and the like, but when a polymer gel electrolyte or a liquid electrolyte is used for the electrolyte layer, a conventionally known binder that binds the positive electrode active material particles to each other, and increases electronic conductivity However, it does not have to include a host polymer, an electrolytic solution, or a lithium salt as a raw material of the polymer electrolyte. Even when a liquid electrolyte is used for the electrolyte layer, the positive electrode layer may not contain a host polymer, an electrolytic solution, a lithium salt, or the like as a raw material of the polymer electrolyte.

As the positive electrode active material, a composite oxide of lithium and transition metal (lithium-transition metal composite oxide) can be suitably used. Specifically, Li—Mn composite oxides such as LiMnO ₂ and LiMn ₂ O ₄ , Li—Co composite oxides such as LiCoO ₂ , Li—Cr such as Li ₂ Cr ₂ O ₇ and Li ₂ CrO _4. Li-Ni composite oxides such as LiNiO ₂ , Li-Fe composite oxides such as Li _x FeO _y , LiFeO ₂ , Li _X FeO _Y, and Li— such as Li _x V _y O _z Li metal oxides such as V-based composite oxides and those obtained by substituting some of these transition metals with other elements (for example, LiNi _x Co _1-x O ₂ (0 <x <1) etc.) can be used. However, the present invention is not limited to these materials. These lithium-transition metal composite oxides are excellent in reactivity and cycle durability and are low-cost materials. Therefore, using these materials for the electrodes is advantageous in that a battery having excellent output characteristics can be formed. In addition, transition metal and lithium phosphate compounds and sulfate compounds such as LiFePO ₄ ; transition metal oxides and sulfides such as V ₂ O ₅ , MnO ₂ , TiS ₂ , MoS ₂ , and MoO ₃ ; PbO ₂ , AgO, NiOOH etc. are mentioned.

  Among the positive electrode active material materials, a Li—Mn composite oxide is desirable. This is because by using the Li—Mn-based composite oxide, the profile can be tilted, and the reliability at the time of abnormality is improved. That is, the voltage-SOC profile can be tilted by making the positive electrode active material a Li-Mn composite oxide. As a result, the state of charge (SOC) of the battery is determined by measuring the voltage, so that the battery can detect and deal with particularly unstable overcharge and possible power states. It becomes possible to improve the property. In addition, the Li—Mn-based composite oxide has a mild reaction even when the battery fails due to overcharge or overdischarge, and can be said to have high reliability in an abnormal state. As a result, there is an advantage that it becomes easy to detect the voltage (potential) of each single cell layer and the bipolar battery or the general battery.

  The average particle diameter of the positive electrode active material is desirably in the range of 0.1 to 50 μm, preferably 0.5 to 20 μm, more preferably 0.5 to 5 μm from the viewpoint of reducing the electrode resistance of the battery. .

  Examples of the conductive aid include acetylene black, carbon black, graphite, various carbon fibers, and carbon nanotubes. However, it is not necessarily limited to these.

  As the binder, polyvinylidene fluoride (PVDF), SBR, polyimide, or the like can be used. However, it is not necessarily limited to these.

  Among the above electrolytes, the polymer gel electrolyte is a solid polymer electrolyte having ion conductivity containing an electrolyte used in a lithium ion secondary battery that is not bipolar type. A polymer skeleton that does not have the same electrolyte solution is also included. Therefore, the polymer solid electrolyte among the electrolytes is a polymer solid electrolyte having ion conductivity.

Here, the electrolytic solution (electrolyte salt and plasticizer) contained in the polymer gel electrolyte is not particularly limited, and various conventionally known electrolytic solutions can be appropriately used. For example, inorganic acid anion salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiTaF ₆ , LiAlCl ₄ , Li ₂ B ₁₀ Cl ₁₀ , LiBOB (lithium bisoxide borate), LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, at least one kind selected from organic acid anion salts such as Li (C ₂ F ₅ SO ₂ ) ₂ N (lithium bis (perfluoroethylenesulfonylimide); also referred to as LiBETI) Cyclic carbonates such as propylene carbonate and ethylene carbonate; lithium carbonate (electrolyte salt); chain carbonates such as dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, Ethers such as 1,2-dimethoxyethane and 1,2-dibutoxyethane; lactones such as γ-butyrolactone; nitriles such as acetonitrile; esters such as methyl propionate; amides such as dimethylformamide; A material using a plasticizer (organic solvent) such as an aprotic solvent in which at least one selected from methyl formate or a mixture of two or more thereof can be used. However, it is not necessarily limited to these.

  Examples of the solid polymer electrolyte having ion conductivity include known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

  For example, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), etc. are used as the polymer having no lithium ion conductivity used in the polymer gel electrolyte. it can. However, it is not necessarily limited to these. Note that PAN, PMMA, etc. are in a class that has almost no ionic conductivity, and therefore can be a polymer having the above ionic conductivity, but here, they are used for a polymer gel electrolyte. This is exemplified as a polymer having no lithium ion conductivity.

The ion as the conducting electrolyte supporting salts to improve the (lithium salt), for _{example, LiPF 6, LiBF 4, LiClO} 4, LiAsF 6, LiTaF 6, LiAlCl 4, Li 2 B 10 Cl ₁₀ and the like inorganic acid anion A salt, an organic acid anion salt such as Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, or a mixture thereof can be used. However, it is not necessarily limited to these.

  The ratio (mass ratio) between the host polymer and the electrolytic solution in the polymer gel electrolyte may be determined according to the purpose of use, but is in the range of 2:98 to 90:10. That is, the leakage of the electrolyte from the electrolyte material in the battery electrode can be effectively sealed by forming an insulating layer described later. Therefore, it is possible to give priority to battery characteristics relatively with respect to the ratio (mass ratio) between the host polymer and the electrolytic solution in the polymer gel electrolyte.

  Examples of the additive include trifluoropropylene carbonate for enhancing battery performance and life, and various fillers as reinforcing materials.

  The thickness of the positive electrode layer (positive electrode active material film thickness) is not particularly limited, and is determined in consideration of the intended use of the battery (emphasis on output, emphasis on energy, etc.) and ion conductivity, as described for the blending amount. However, it should be determined in consideration of the intended use of the battery (emphasis on output, energy, etc.) and ion conductivity. Therefore, the thickness of the positive electrode layer (positive electrode active material film thickness) is about 1 to 500 μm.

  The amount of positive electrode active material, conductive additive, binder, polymer electrolyte (host polymer, electrolyte, etc.), lithium salt, etc. in the positive electrode layer depends on the intended use of the battery (output, energy, etc.), ion conduction It should be determined in consideration of sex.

[Negative electrode layer (negative electrode active material layer)]
The negative electrode layer includes a negative electrode active material. In addition to this, a conductive auxiliary agent for increasing electronic conductivity, a binder, a polymer electrolyte (host polymer, electrolytic solution, etc.), a lithium salt for increasing ionic conductivity, an additive, etc. may be included. When a polymer gel electrolyte is used for the molecular electrolyte layer, it only needs to contain a conventionally known binder that binds the negative electrode active material fine particles to each other, a conductive auxiliary agent for increasing electronic conductivity, and the like. The host polymer, electrolyte solution, lithium salt and the like may not be contained. Even when a solution electrolyte is used for the electrolyte layer, the negative electrode layer may not contain a host polymer, an electrolytic solution, a lithium salt, or the like as a raw material of the polymer electrolyte. Except for the type of the negative electrode active material, the contents are basically the same as those described in the section “Positive electrode layer”, and thus the description thereof is omitted here.

As the negative electrode active material, carbon, metal compound, metal oxide, Li metal compound, Li metal oxide (including lithium-transition metal composite oxide), boron-added carbon, graphite, or the like can be used. These may be used alone or in combination of two or more. Examples of the carbon include conventionally known carbon materials (carbon materials) such as graphite carbon, hard carbon, soft carbon, and activated carbon. Examples of the metal compound include LiAl, LiZn, Li ₃ Bi, Li ₃ Cd, Li ₃ Sd, Li ₄ Si, Li _4.4 Pb, Li _4.4 Sn, Li _0.17 C (LiC ₆ ), and the like. It is done. The metal _{oxides, SnO, SnO 2, GeO,} GeO 2, In 2 O, In 2 O 3, PbO, PbO 2, Pb 2 O 3, Pb 3 O 4, Ag 2 O, AgO, Ag 2 O ₃ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , SiO, ZnO, CoO, NiO, FeO, SnB _X P _Y O _Z , Nb ₂ O _{5 and the} like. Examples of the Li metal compound include Li ₃ FeN ₂ , Li _2.6 Co _0.4 N, Li _2.6 Cu _0.4 N, and the like. Examples of the Li metal oxide (lithium-transition metal composite oxide) include a lithium-titanium composite oxide represented by Li _x Ti _y O _z such as Li ₄ Ti ₅ O ₁₂ and a lithium-iron composite such as LiFe _X O _Y. Examples thereof include oxides and lithium-manganese composite oxides such as LiMn _X O _Y. Examples of the boron-added carbon include boron-added carbon and boron-added graphite. However, in this invention, it should not be restrict | limited to these but a conventionally well-known thing can be utilized suitably. The boron content in the boron-added carbon is preferably in the range of 0.1 to 10% by mass, but should not be limited to this.

  The negative electrode active material is preferably selected from a crystalline carbon material and an amorphous carbon material. By using these, the profile can be tilted. Specifically, the voltage-SOC profile can be tilted by selecting the negative electrode active material from a crystalline carbon material or an amorphous carbon material. As a result, the state of charge (SOC) of the battery can be determined by measuring the voltage, so that the battery can detect and deal with a particularly unstable overcharge / overdischarge state. It becomes possible to improve the property. This effect is particularly remarkable in amorphous carbon and is effective but not particularly limited. As a result, it becomes easy to detect the voltage of each single cell layer, bipolar battery or general battery. The crystalline carbon material here refers to a graphite-based carbon material, and includes the above-described graphite carbon and the like. The non-crystalline carbon material refers to a hard carbon-based carbon material, and includes the hard carbon and the like.

[Electrolyte layer]
The electrolyte layer is selected from (a) a polymer gel electrolyte, (b) a polymer solid electrolyte, or (c) a separator (including a nonwoven fabric separator) impregnated with these polymer electrolytes or electrolytic solutions, depending on the purpose of use. It can also be applied to.

(A) Polymer gel electrolyte The polymer gel electrolyte is not particularly limited, and those used in conventional gel electrolyte layers can be appropriately used. Here, the gel electrolyte refers to one in which an electrolytic solution is held in a polymer matrix. In the present invention, the difference between an all solid polymer electrolyte (also simply referred to as a polymer solid electrolyte) and a gel electrolyte is as follows.

  A gel electrolyte is an all-solid polymer electrolyte such as polyethylene oxide (PEO) containing an electrolytic solution used in a normal lithium ion battery.

  A gel electrolyte is a polymer electrolyte such as polyvinylidene fluoride (PVDF) in which a polymer skeleton having no lithium ion conductivity is held.

  -The ratio of the polymer constituting the gel electrolyte (also referred to as host polymer or polymer matrix) and the electrolytic solution is wide. When 100% by mass of the polymer is an all solid polymer electrolyte and 100% by mass of the electrolytic solution is a liquid electrolyte, an intermediate thereof Are all gel electrolytes.

  A host polymer of the gel electrolyte is not particularly limited, and a conventionally known one can be used. Preferably, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG ), Polyacrylonitrile (PAN), polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP), poly (methyl methacrylate) (PMMA) and copolymers thereof are preferable, and the solvents include ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (GBL), dimethyl carbonate (DMC), diethyl carbonate (DEC), and mixtures thereof are preferred.

The electrolyte solution (electrolyte salt and plasticizer) of the gel electrolyte is not particularly limited, and conventionally known ones can be used. Specifically, as long as usually used in a lithium ion battery, for _{example, LiPF 6, LiBF 4, LiClO} 4, LiAsF 6, LiTaF 6, LiAlCl 4, Li 2 B 10 Cl ₁₀ and the like inorganic acid anion At least one lithium salt (electrolyte salt) selected from organic acid anion salts such as a salt, LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N Cyclic carbonates such as propylene carbonate and ethylene carbonate; chain carbonates such as dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane , 1,2-dibutoxyethane, etc. Lactones such as γ-butyrolactone; nitriles such as acetonitrile; esters such as methyl propionate; amides such as dimethylformamide; at least one or more selected from methyl acetate and methyl formate A mixed organic solvent (plasticizer) such as an aprotic solvent can be used. However, it is not necessarily limited to these.

  The ratio of the electrolytic solution in the gel electrolyte in the present invention is not particularly limited, but is preferably about several mass% to 98 mass% from the viewpoint of ionic conductivity. The present invention is particularly effective for a gel electrolyte having a large amount of electrolytic solution in which the proportion of the electrolytic solution is 70% by mass or more.

  In the present invention, the amount of the electrolyte contained in the gel electrolyte may be substantially uniform inside the gel electrolyte, or may be decreased in an inclined manner from the central portion toward the outer peripheral portion. . The former is preferable because reactivity can be obtained in a wider range, and the latter is preferable in that the sealing property of the all solid polymer electrolyte portion in the outer peripheral portion with respect to the electrolytic solution can be improved. When decreasing gradually from the central part toward the outer peripheral part, polyethylene oxide (PEO), polypropylene oxide (PPO) and copolymers thereof having lithium ion conductivity are used as the host polymer. It is desirable.

(B) Polymer solid electrolyte The all solid polymer electrolyte is not particularly limited, and a conventionally known one can be used. Specifically, it is a layer composed of a polymer having ion conductivity, and the material is not limited as long as it exhibits ion conductivity. Examples of the all solid polymer electrolyte include known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof. The solid polymer electrolyte contains a lithium salt in order to ensure ionic conductivity. As the lithium salt, LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , or a mixture thereof can be used. However, it is not necessarily limited to these. A polyalkylene oxide polymer such as PEO and PPO can dissolve lithium salts such as LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , and LiN (SO ₂ C ₂ F ₅ ) ₂ well. Moreover, excellent mechanical strength is exhibited by forming a crosslinked structure.

(C) Separator (including non-woven fabric separator) impregnated with the polymer electrolyte or electrolytic solution (electrolyte salt and plasticizer)
As the electrolyte that can be impregnated in the separator, the same electrolyte (electrolyte salt and plasticizer) solution as described in (a) and (b) or (a) described above can be used. The description in is omitted.

  The separator is not particularly limited, and a conventionally known separator can be used. For example, a porous sheet made of a polymer that absorbs and holds the electrolyte (for example, a polyolefin microporous separator). Etc.) can be used. The polyolefin microporous separator having the property of being chemically stable to an organic solvent has an excellent effect that the reactivity with the electrolyte (electrolytic solution) can be kept low.

  Examples of the polymer material include polyethylene (PE), polypropylene (PP), a laminate having a three-layer structure of PP / PE / PP, and polyimide.

  The thickness of the separator cannot be unambiguously defined because it varies depending on the intended use. However, in the case of a secondary battery for driving a motor such as an electric vehicle (EV) or a hybrid electric vehicle (HEV), a single layer is used. Or it is desirable that it is 4-60 micrometers in a multilayer. The mechanical strength in the thickness direction is desirable because the thickness of the separator is within such a range, and it is desirable to narrow the gap between the electrodes for high output and prevention of short-circuiting caused by fine particles entering the separator. And there is an effect of ensuring high output performance. In addition, when a plurality of batteries are connected, the electrode area increases, so that it is desirable to use a thick separator in the above range in order to increase the reliability of the battery.

  The fine pore diameter of the separator is desirably 1 μm or less (usually a pore diameter of about several tens of nm). Due to the fact that the average diameter of the micropores in the separator is within the above range, the “shutdown phenomenon” that the separator melts due to heat and the micropores close quickly occurs, resulting in higher reliability during abnormalities, resulting in heat resistance. Has the effect of improving. In other words, when the battery temperature rises due to overcharging (in an abnormal state), the “shutdown phenomenon” that the separator melts and closes the micropores occurs quickly, so that the positive electrode (+) of the battery (electrode) Li ions cannot pass through to the negative electrode (−) side, and no further charge is possible. As a result, overcharging cannot be performed and overcharging is eliminated. As a result, the heat resistance (safety) of the battery is improved, and it is possible to prevent gas from being released and the heat fusion part (seal part) of the battery exterior material from being opened. Here, the average diameter of the micropores of the separator is calculated as an average diameter obtained by observing the separator with a scanning electron microscope or the like and statistically processing the photograph with an image analyzer or the like.

  The separator preferably has a porosity of 20 to 50%. The separator's porosity is within the above range, preventing output from being reduced due to the resistance of the electrolyte (electrolyte), and preventing the short circuit caused by fine particles penetrating the separator's pores (micropores). It has the effect of securing both sexes. Here, the porosity of the separator is a value obtained as a volume ratio from the density of the raw material resin and the density of the separator of the final product.

  The amount of electrolyte impregnated into the separator may be impregnated up to the holding capacity range of the separator, but may be impregnated beyond the holding capacity range. This can be impregnated as long as it can be retained in the electrolyte layer because a seal portion is provided in the electrolyte and the electrolyte solution can be prevented from exuding from the electrolyte layer.

  The nonwoven fabric separator used for holding the electrolyte is not particularly limited, and can be manufactured by entwining the fibers into a sheet. Moreover, the spun bond etc. which are obtained by fusing fibers by heating can also be used. In other words, it may be in the form of a sheet formed by arranging fibers in a web (thin cotton) shape or mat shape by an appropriate method, and joining them using an appropriate adhesive or the fusing force of the fibers themselves. The adhesive is not particularly limited as long as it has sufficient heat resistance at the temperature during manufacture and use, and is stable without any reactivity or solubility with respect to the gel electrolyte. In addition, conventionally known ones can be used. In addition, the fiber used is not particularly limited, and for example, conventionally known fibers such as cotton, rayon, acetate, nylon, polyester, polypropylene, polyethylene such as polyethylene, polyimide, and aramid can be used. Depending on (such as mechanical strength required for the electrolyte layer), they are used alone or in combination. Further, the bulk density of the nonwoven fabric is not particularly limited as long as sufficient battery characteristics can be obtained by the impregnated polymer gel electrolyte. That is, if the bulk density of the nonwoven fabric is too large, the proportion of the non-electrolyte material in the electrolyte layer becomes too large, which may impair the ionic conductivity in the electrolyte layer.

  The porosity of the nonwoven fabric separator is preferably 50 to 90%. If the porosity is less than 50%, the electrolyte retention deteriorates, and if it exceeds 90%, the strength is insufficient. Furthermore, the thickness of the nonwoven fabric separator may be the same as that of the electrolyte layer, preferably 5 to 200 μm, particularly preferably 10 to 100 μm. When the thickness is less than 5 μm, the electrolyte retention deteriorates, and when it exceeds 200 μm, the resistance increases.

  The electrolyte layers (a) to (c) may be used in one battery.

  In addition, the polymer electrolyte may be contained in the electrolyte layer, the positive electrode active material layer, and the negative electrode active material layer, but the same polymer electrolyte may be used, or different polymer electrolytes may be used depending on the layer.

  By the way, a host polymer for a polymer electrolyte that is preferably used at present is a polyether polymer such as PEO and PPO. For this reason, the oxidation resistance on the positive electrode side under high temperature conditions is weak. Therefore, when using a positive electrode agent having a high oxidation-reduction potential that is generally used in a solution-type lithium ion battery, the capacity of the negative electrode is preferably smaller than the capacity of the positive electrode facing through the polymer electrolyte layer. . If the capacity of the negative electrode is less than the capacity of the opposing positive electrode, it is possible to prevent the positive electrode potential from rising excessively at the end of charging. In addition, the capacity | capacitance of a positive electrode and a negative electrode can be calculated | required from manufacturing conditions as theoretical capacity | capacitance at the time of manufacturing a positive electrode and a negative electrode. You may measure the capacity | capacitance of a finished product directly with a measuring device.

  However, if the capacity of the negative electrode is smaller than the capacity of the opposing positive electrode, the negative electrode potential will be too low and the durability of the battery may be impaired, so it is necessary to pay attention to the charge / discharge voltage. For example, care should be taken not to lower the durability by setting the average charge voltage of one cell (single cell layer) to an appropriate value for the oxidation-reduction potential of the positive electrode active material.

  The thickness of the electrolyte layer constituting the battery is not particularly limited. However, in order to obtain a compact bipolar polymer battery, it is preferable to make it as thin as possible as long as the function as an electrolyte can be secured. The thickness of a general electrolyte layer is 5 to 200 μm, preferably about 10 to 100 μm.

[Insulation layer]
The insulating layer is applied on the bipolar battery side. The insulating layer is formed around each electrode for the purpose of preventing adjacent collectors in the bipolar battery from contacting each other and short-circuiting due to slight unevenness at the end of the laminated electrode. Is.

  As the material used for the insulating layer, in addition to insulation, any material having heat resistance under battery operating temperature, resistance to electrolytic solution, etc. may be used. For example, epoxy resin, rubber, polyethylene, polypropylene, polyimide, etc. However, from the viewpoints of corrosion resistance, chemical resistance, ease of production (film forming property), economy, and the like, an epoxy resin is preferable.

[Positive electrode and negative electrode terminal plate]
The positive electrode and the negative electrode terminal plate are used as necessary on the bipolar battery side. That is, depending on the stacking or winding structure of the battery, the positive electrode and the negative electrode tab (electrode terminal) may be taken out from the outermost current collector directly or through the electrode lead. It is not necessary to use it.

  When using positive and negative terminal plates, in addition to having a function as a terminal, it is better to be as thin as possible from the viewpoint of thinning, but the laminated electrode, electrolyte and current collector all have mechanical strength. Since it is weak, it is desirable to have strength to sandwich and support these from both sides. Furthermore, from the viewpoint of suppressing the internal resistance from the electrode terminal plate to the electrode tab, it can be said that the thickness of the positive electrode and the negative electrode terminal plate is usually preferably about 0.1 to 2 mm.

  As the material of the positive electrode and the negative electrode terminal plate, for example, aluminum, copper, titanium, nickel, stainless steel (SUS), alloys thereof, and the like can be used.

  The material of the positive electrode terminal plate and the negative electrode terminal plate may be the same material or different materials. Furthermore, the positive electrode and the negative electrode terminal plate may be a laminate of different materials. In these positive electrode and negative electrode terminal plates, since they may be close to or in close contact with the battery outer packaging material, if necessary, the high resistance layer is provided on the outer surface of the electrode terminal plate as in the case of the electrode tabs. Needless to say, it may be provided appropriately.

[Positive electrode and negative electrode lead]
The positive electrode and the negative electrode lead may be used as necessary. As the positive electrode and the negative electrode lead, known electrode leads used in secondary batteries can be used. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. The material of the positive electrode lead and the negative electrode lead may be the same material or different materials. Furthermore, the positive electrode and the negative electrode lead may be a laminate of different materials. In addition, since these positive and negative electrode leads may also be close to or in close contact with the battery outer packaging material, if necessary, a high resistance layer is appropriately applied to a required portion on the surface of the electrode lead as in the case of the electrode tab. Needless to say, it may be provided.

[Positive electrode and negative electrode tab]
The positive and negative electrode tabs used in the present invention may be connected between the positive and negative electrode leads connected to the current collector (or the electrode terminal plate connected thereto) of the outermost electrode in the bipolar battery. Good. Similarly, in a general battery, it may be connected between positive / negative electrode leads connected to each current collector. In a bipolar battery, the battery may be connected to positive / negative terminal plates or positive / negative electrode leads connected to the current collector of the outermost electrode. Similarly, in a general battery, it may be connected to positive / negative electrode terminal plates or positive / negative electrode leads connected to each current collector. Further, in the bipolar battery, a part of the current collector of the outermost layer electrode may be extended. Similarly, in a general battery, one of the current collectors may be formed to be extended, and it should not be particularly limited.

  In addition, the part taken out from the battery exterior material to the outside of the battery is not heat-resistant so that it does not affect products (for example, automobile parts, especially electronic devices) by contacting with peripheral devices or wiring and leaking electricity. It may be covered with an insulating heat-shrinkable tube.

  Moreover, the electrode tab used for this invention can use the well-known electrode tab used with a secondary battery. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. The materials of the positive electrode tab and the negative electrode tab may be the same material or different materials. Furthermore, the positive electrode and the negative electrode tab may be formed by stacking multiple layers of metals (including alloys) of different materials.

  The thickness of the electrode tab is preferably thinner from the viewpoint of improving the airtightness and waterproofness of the portion sandwiched between the exterior material seal parts, while the thicker is desirable from the viewpoint of reducing electrical resistance. May be appropriately determined according to the purpose of use, but is usually in the range of 1 to 500 μm, preferably 1 to 100 μm.

  In addition, since the method of taking out the electrode tab from the battery is as described above, the description thereof is omitted here. In order to form a battery pack by connecting a plurality of these batteries, it can be said that it is desirable to take out the positive electrode tab and the negative electrode tab separately from the sides facing each other because of the wiring. Moreover, you may provide a high resistance layer also in the tab metal surface as needed.

[Detection tab]
In the case of a bipolar battery, each cell is provided with a detection tab for detecting a voltage for each cell (single cell layer) in the battery. Since this has already been described, a description thereof is omitted here. Since only the voltage for each cell (about 4.2 V) is applied to the voltage detection tab, it is not necessary to form a high resistance layer like the electrode tab, but there is no particular limitation.

  The same material as the electrode tab can be used for the voltage detection tab. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. Although it is desirable to use the same material for each voltage detection tab, different materials may be used. Furthermore, the voltage detection tab may be a laminate of metals (including alloys) made of different materials.

[Battery exterior materials]
In the present invention, in the same manner as in the past, the waterproof and sealing properties of the battery are ensured, the battery is further reduced in weight, and from the viewpoint of preventing external impact and environmental degradation during use, the battery stack as the battery body is used. A polymer metal composite film is used as a battery exterior material for housing the entire body (or battery winding body). The polymer metal composite film is not particularly limited, and any conventionally known one can be appropriately applied. For example, a metal (including alloy) layer such as aluminum, stainless steel, nickel, copper, or the like. A polymer metal composite film having both surfaces covered with a resin layer (skin resin layer, metal layer-between-tab resin layer) of an insulator (preferably heat resistant insulator) such as a polypropylene film can be used. Examples of the resin layer of the insulator (preferably heat-resistant insulator) include, for example, a polyethylene tetraphthalate film (heat-resistant insulating film), a nylon film (heat-resistant insulating film), a polyethylene film (heat-bonding insulating film), Examples thereof include a polypropylene film (heat fusion insulating film), and these may be applied to the skin resin layer side and the metal layer-tab resin layer side according to the purpose.

  As the metal layer, aluminum is required because it requires heat resistance rather than insulation against high voltage, a high barrier property against external oxygen, water vapor and light (such as ultraviolet rays), and a soft material with excellent strength against bending. desirable. The film thickness of the metal layer is not particularly limited as long as the above characteristics can be sufficiently exhibited, and is in the range of 1 to 100 μm, preferably 5 to 50 μm.

  The above-mentioned skin resin layer does not require heat fusibility, and is required to have external insulation, weather resistance, abrasion resistance, barrier properties against external oxygen and water vapor, heat resistance, etc. A desired material such as an insulating film) or a nylon film (heat-resistant insulating film) may be selected. Moreover, the film thickness of a skin resin layer should just be able to fully express the said characteristic, and is 1-50 micrometers, Preferably it is the range of 5-30 micrometers.

  In the resin layer between the metal layer and the tub, internal insulation, heat-fusibility, chemical resistance (resistance to electrolytic solution, etc.), barrier property against oxygen and water vapor, gas generated by charging / discharging, heat resistance, etc. Therefore, a desired material such as a polyethylene film (heat-fusing insulating film), a polypropylene film (heat-fusing insulating film) or the like may be selected. Moreover, the film thickness of the resin layer between a metal layer and a tab should just be able to fully express the said characteristic, and is 1-100 micrometers, Preferably it is the range of 5-50 micrometers.

  The film thickness of the entire polymer metal composite film is not particularly limited as long as it can exhibit the above-described functions required for battery exterior materials, but is usually in the range of 20 to 150 μm, preferably 50 to 120 μm. It is.

  In addition, these metal layers, skin resin layers, and metal layer-tab resin layers may be formed by laminating layers of different materials. In addition, when two upper and lower polymer metal composite films are used by heat-sealing, the material of each layer in these two polymer metal composite films may be the same or different. May be used.

  In the present invention, a polymer metal composite film is used to form a seal part by joining a part or all of its peripheral part by thermal fusion, and the battery stack is housed and sealed. In this case, the positive electrode and the negative electrode tab are sandwiched between the seal portions (heat fusion portions), and the insulation is ensured to expose the leading end of the positive electrode and the negative electrode tab to the outside of the battery exterior material. What is necessary is just a structure. In addition, it is preferable to use a polymer metal composite film having excellent thermal conductivity in that heat can be efficiently transmitted from a heat source of an automobile and the inside of the battery can be quickly heated to the battery operating temperature.

  It should be noted that the general battery and the bipolar battery preferably have the same positive electrode and negative electrode materials as the above-described constituent elements, but even if they are different, any material can be used as long as it satisfies the requirements of the present invention. It is not limited.

  Next, the assembled battery of the present invention is an assembled battery in which two types of batteries of a general battery group in which a bipolar battery and a general battery are connected in series for the number of combinations of the positive electrode and the negative electrode of the bipolar battery are connected in parallel. The bipolar battery has a detection tab connected to each single cell layer configured, and the tab connection portion of each general battery having the same potential level as that of the detection tab is electrically coupled. It is characterized by being. By adopting the configuration of the present invention, an assembled battery that compensates for each other's weaknesses can be obtained by combining a bipolar battery that emphasizes output and a general battery group that emphasizes energy, and the weight and size of the assembled battery can be reduced. In particular, in the assembled battery of the present invention, in order to increase the capacity of the bipolar battery and reduce the internal resistance, it is necessary to use a bipolar battery in which the electrode area is increased by paralleling the electrodes of one unit battery (cell). This is advantageous. Therefore, even when an assembled battery configured using a bipolar battery is used as a vehicle power source, the capacity of the bipolar battery can be increased, the internal resistance of the battery can be reduced, and the required high output and high energy can be achieved. It is possible to provide an assembled battery that can achieve both. The assembled battery of the present invention has a structure in which the bipolar battery has an output sharing and the general battery group has an energy sharing. This is a very effective means in an assembled battery in which it is difficult to achieve both output and energy.

  1 and 7 to 9 show a basic configuration inside the assembled battery 1 in which the bipolar battery 3 and the general battery group 7 are connected in parallel. In the assembled battery of the present invention, these basic configurations may be housed in an assembled battery case. FIG. 11 is a schematic view schematically showing the state of the assembled battery in which the basic configuration of the assembled battery shown in FIG. 7 is housed in the assembled battery case.

  The basic configuration of the assembled battery 1 shown in FIG. 11 is as described in FIGS. In FIG. 11, the basic configuration of the assembled battery is housed in a metal assembled battery case 55. A positive electrode terminal 62 and a negative electrode terminal 64 are formed on the front side surface of the assembled battery case 55, and the positive electrode and negative electrode tabs 13 and 15 at both ends in the basic configuration of the assembled battery, the positive electrode terminal 62, and the negative electrode terminal 64 are terminals. Connected by leads 59. Further, in order to monitor the battery voltage, the detection tab terminal 54 is installed at the front side of the assembled battery case 55 where the positive terminal 62 and the negative terminal 64 are provided. The battery voltage can include each cell layer of the bipolar battery, and further, the voltage between the tabs of the bipolar battery and the general battery. And all the detection tabs of each bipolar battery (and also a general battery) are connected to the detection tab terminal 54 via a detection line (not shown). An external elastic body 52 is attached to the bottom of the assembled battery case 55. As a result, when a plurality of assembled batteries 1 are stacked to form a composite assembled battery, the distance between the assembled batteries 1 can be maintained, and vibration isolation, impact resistance, insulation, heat dissipation, and the like can be improved. .

  Next, at least two or more of the above assembled batteries may be combined in series, parallel, or in series and parallel. Thereby, it becomes possible to respond to the demand for the battery capacity and output for each purpose of use relatively inexpensively without producing a new assembled battery. That is, the composite battery pack of the present invention is characterized in that at least two or more battery packs are connected in series, in parallel, or in series and parallel, and a reference battery pack is manufactured and combined. By using an assembled battery, the specifications of the assembled battery can be changed for each vehicle application. Thereby, since it is not necessary to manufacture many assembled battery types with different specifications, the composite assembled battery cost can be reduced. In the above composite assembled battery, not all the assembled batteries are necessarily the assembled batteries of the present invention.

  12 is a schematic diagram of a composite assembled battery in which six assembled batteries, each of which has six basic configurations of the assembled battery shown in FIG. 9 housed in the assembled battery case shown in FIG. 11, are connected in parallel. Each assembled battery constituting the composite assembled battery is integrated by a connecting plate and a fixing screw, and an anti-vibration structure is formed by installing an elastic body between the assembled batteries. The tabs of the assembled battery are connected by a plate-like bus bar. As a result, as shown in FIG. 12, six sets of the assembled batteries 1 housed in the assembled battery case are connected in parallel to form a composite assembled battery 70. That is, in order to obtain the composite assembled battery 70, the positive electrode terminal 62 and the negative electrode terminal 64 of the assembled battery tab provided on the lid of each assembled battery case 55 are replaced with the external positive electrode and external negative electrode terminal portions that are plate-like bus bars. The assembled battery positive terminal and the assembled battery negative terminal connecting plates 72 and 74 are electrically connected. In addition, a connecting plate 76 having an opening corresponding to the fixing screw hole is fixed to each screw hole (not shown) provided on both side surfaces of each assembled battery case 55 with a fixing screw 77, and each set is assembled. The batteries 1 are connected to each other. Furthermore, the positive electrode terminal 62 and the negative electrode terminal 64 of each assembled battery 1 are protected by a positive electrode and a negative electrode insulating cover, respectively, and are identified by color-coding into appropriate colors, for example, red and blue. Further, between the assembled batteries 1, specifically, an external elastic body 52 is installed at the bottom of the assembled battery case 55 to form a vibration isolation structure.

  Moreover, in the said composite assembled battery, it is desirable to connect the some assembled battery which comprises this so that attachment or detachment is possible respectively. As described above, in the composite assembled battery in which a plurality of assembled batteries are connected in series and parallel, even if some of the batteries and the assembled battery fail, the repair can be performed only by replacing the failed part.

  The vehicle according to the present invention is characterized in that the assembled battery and / or the composite assembled battery is mounted. That is, not only the composite battery pack but also the battery pack may be mounted on the vehicle depending on the intended use, or the composite battery pack and the battery pack may be mounted in combination. This makes it possible to meet a large vehicle demand for space by using a light and small battery. By reducing the battery space, the weight of the vehicle can be reduced.

  As the vehicle on which the composite assembled battery and / or assembled battery of the present invention can be mounted as a driving power source or an auxiliary power source, the above-described electric vehicle, fuel cell vehicle and hybrid vehicle thereof are preferable, but are not limited thereto. It is not a thing.

  FIG. 13 is a schematic diagram schematically showing a state in which the composite battery pack is mounted on a vehicle. As shown in FIG. 13, in order to mount the composite battery pack 70 on a vehicle (for example, an electric vehicle or the like), it is desirable to mount it under a seat (seat) at the center of the vehicle body of the electric vehicle 80. This is because if the vehicle is mounted under the seat, the interior space and the trunk room can be widened. However, the place where the composite battery pack 80 and the like are mounted is not limited to the position under the seat, but may be the under floor of the vehicle, the back of the seat back, the lower portion of the rear trunk room, or the engine room in front of the vehicle.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples.

  In the following Examples 1 and 2, the positive / negative electrode configuration was a parallel structure of a 50V battery group of 12 layers of 50V bipolar batteries and 12 straight general batteries (with connection of each layer). In Examples 3 to 4, the positive / negative electrode configuration was a parallel structure of a 67V general battery group of 16-layer 67V bipolar battery and 16-straight general battery (with connection of each layer). In Comparative Example 1, a parallel structure battery similar to Example 1 was used except that there was no connection of each layer. This will be described in detail below.

Example 1
As a current collector, a positive electrode material containing a Li—Mn composite oxide was applied to one side of a SUS foil (thickness: 20 μm) at a thickness of 30 μm to form a positive electrode layer. After that, a negative electrode layer was formed by applying a negative electrode material containing graphite as a crystalline carbon material to a thickness of 30 μm on the opposite surface of the SUS foil on which the positive electrode layer was formed, thereby forming a bipolar electrode.

  The precursor of the cross-linked gel electrolyte was infiltrated into a PET non-woven fabric separator (about 30 μm thick), and was layered on the bipolar electrode obtained previously. Further, a similar bipolar electrode was stacked thereon to constitute a 12-layer (12 electrode unit) bipolar battery.

  An Al positive electrode tab (200 μm thickness: width 100 mm) is vibration welded to the positive electrode side (end portion of the outermost layer current collector) of the 12-layer bipolar electrode, and is attached to the negative electrode side (end portion of the outermost layer current collector). Vibrated and welded a negative electrode tab made of Cu (thickness of 200 μm: width of 100 mm). Further, SUS (20 μm thickness: width 10 mm) was taken out from the side different from the electrode tab taking-out side of each cell layer as the detection tab (see FIG. 2A). The entire power generating element (battery body) having the tab-integrated 12-layer bipolar electrode was sealed with a laminate material (the appearance was similar to the front view of FIG. 2A).

  This 12-layer (12 cells) bipolar battery was heated and crosslinked at about 80 ° C. for about 2 hours to produce a 12-layer bipolar battery.

  A general battery was fabricated using the same material as that used in the bipolar battery. That is, a positive electrode material containing a Li—Mn composite oxide was applied to both surfaces of a SUS foil (thickness 20 μm) as a positive electrode current collector with a thickness of 30 μm on one side to form a positive electrode layer. A negative electrode material containing graphite as a crystalline carbon material was applied to both surfaces of a SUS foil (thickness 20 μm) as a negative electrode current collector with a thickness of 30 μm on one side to form a positive electrode layer. A power generation element (battery body) was formed by sandwiching a cross-linked gel electrolyte precursor in a PET nonwoven fabric separator (about 30 μm thick) between the positive electrode and the negative electrode. The entire power generation element (battery body) was sealed with a laminate material. The obtained general battery was heated and crosslinked at about 80 ° C. for about 2 hours to produce a general battery having 10 positive electrodes and 11 negative electrodes. The electrode tabs of the general battery were directly connected by vibration welding, and each battery unit was joined to the detection tab of the bipolar battery with an Al wire. The detection tab and the electrode tab of the general battery and the Al wire were joined by vibration welding. An Al wire having a total cross-sectional area of the positive electrode and negative electrode tab of the bipolar battery that is 100 times the cross-sectional area of the Al wire, which is a connection between the detection tab and the connection tab of each general battery in series, was used. In addition, as described above, a material whose Young's modulus of the material of all connections is equal to or less than the Young's modulus of the material of the detection tab and the connection tab was used.

  Wiring was performed so that the distance between the center of gravity of the bipolar battery and the center of gravity of the general battery group was approximately halfway between the long and short sides of the bipolar battery and the short and short sides of the general battery group.

  After the assembled battery was constructed, the battery was inserted into an aluminum case, and the assembled battery having the appearance of one case 55 in FIG. 12 (the basic configuration inside the assembled battery case was the same as that in FIG. The arrangement of the general battery group was the same as in FIG.

  Basic structure (structure) inside battery pack case, number of stacked bipolar electrodes used to manufacture bipolar battery, number of series of general battery groups, tab cross-sectional area ratio (total cross-sectional area of positive and negative electrode tabs: detection tab + connection Table 1 below shows the cross-sectional area), Young's modulus ratio (Young's modulus of the material of the detection tab + general series connection tab; Young's modulus of the material of the connection), positive electrode active material, and negative electrode active material.

  Further, the obtained assembled battery was measured for the distance between the centers of gravity, the capacity variation, and the average attenuation amount by the test method described below. The obtained results are shown in Table 1 below.

Example 2
Except for producing a 12-layer 50V bipolar battery and a 12V straight general battery 50V general battery group using the same material as used in Example 1, the basic configuration inside the assembled battery case was the same as in FIG. An assembled battery was produced in the same manner as in Example 1.

  The production conditions and test results similar to those of Example 1 are shown in Table 1, and a diagram showing the frequency-vibration transmissibility characteristics obtained by measuring the average reduction amount is shown in FIG.

Example 3
As a current collector, a positive electrode material containing a Li—Mn composite oxide was applied to one side of a SUS foil (thickness: 20 μm) at a thickness of 30 μm to form a positive electrode layer. After that, a negative electrode layer was formed by applying a negative electrode material containing hard carbon as an amorphous carbon material to a thickness of 30 μm on the opposite surface of the SUS foil on which the positive electrode layer was formed, thereby forming a bipolar electrode.

  The precursor of the cross-linked gel electrolyte was infiltrated into a PET non-woven fabric separator (about 30 μm thick), and was layered on the bipolar electrode obtained previously. Furthermore, a similar bipolar electrode was stacked thereon to constitute a 16-layer (16 electrode unit) bipolar battery.

  An Al positive electrode tab (200 μm thickness: width 40 mm) is vibration welded to the positive electrode side (end of the outermost layer current collector) of the 16-layer bipolar electrode, and is attached to the negative electrode side (end of the outermost layer current collector). Vibrated and welded a negative electrode tab made of Cu (thickness: 200 μm: width: 40 mm). Moreover, the product made from SUS (10 micrometers thickness: width 5mm) was taken out from two sides different from the electrode tab taking-out side of each cell layer as a detection tab (refer FIG. 3). The entire power generation element (battery body) having the tab-integrated 16-layer bipolar electrode was sealed with a laminate material (appearance was similar to that shown in the cross-sectional view of FIG. 3).

  This 16-layer (16 cells) bipolar battery was crosslinked by heating at about 80 ° C. for about 2 hours to produce a 16-layer bipolar battery.

  A general battery was fabricated using the same material as that used in the bipolar battery. That is, a positive electrode material containing a Li—Mn composite oxide was applied to both surfaces of a SUS foil (thickness 20 μm) as a positive electrode current collector with a thickness of 30 μm on one side to form a positive electrode layer. A negative electrode material containing hard carbon as an amorphous carbon material was applied to both surfaces of a SUS foil (thickness 20 μm) as a negative electrode current collector with a thickness of 30 μm on one side to form a positive electrode layer. A power generation element (battery body) was formed by sandwiching a cross-linked gel electrolyte precursor in a PET nonwoven fabric separator (about 30 μm thick) between the positive electrode and the negative electrode. The entire power generation element (battery body) was sealed with a laminate material. The obtained general battery was heated and crosslinked at about 80 ° C. for about 2 hours to produce a general battery having 10 positive electrodes and 11 negative electrodes. The electrode tabs of the general battery were directly connected by vibration welding, and each battery unit was joined to the detection tab of the bipolar battery with a Cu wire. The detection tab and the electrode tab of the general battery and the Cu wire were joined by vibration welding. A Cu wire having a total cross-sectional area of the positive electrode and the negative electrode tab of the bipolar battery that is 100 times the cross-sectional area of the Cu wire, which is a connection between the detection tab and the connection tab of each general battery in series, was used. In addition, as described above, a material whose Young's modulus of the material of all connections is equal to or less than the Young's modulus of the material of the detection tab and the connection tab was used.

  Wiring was performed so that the distance between the center of gravity of the bipolar battery and the center of gravity of the general battery group was approximately halfway between the long and short sides of the bipolar battery and the short and short sides of the general battery group.

  After the assembled battery was constructed, this battery was inserted into an aluminum case to obtain an assembled battery having the appearance of one case 55 in FIG. 12 (the basic configuration inside the assembled battery case was arranged in the same manner as in FIG. 8). .

  Basic structure (structure) inside battery pack case, number of stacked bipolar electrodes used to manufacture bipolar battery, number of series of general battery groups, tab cross-sectional area ratio (total cross-sectional area of positive and negative electrode tabs: detection tab + connection Table 1 below shows the cross-sectional area), Young's modulus ratio (Young's modulus of the material of the detection tab + general series connection tab; Young's modulus of the material of the connection), positive electrode active material, and negative electrode active material.

  Further, the obtained assembled battery was measured for the distance between the centers of gravity, the capacity variation, and the average attenuation amount by the test method described below. The obtained results are shown in Table 1 below.

Example 4
Using the same material as used in Example 3, a 67-layer bipolar battery of 16 layers and a 67-volt general battery group of 16 straight general batteries were prepared, and the basic configuration inside the assembled battery case was the same as in FIG. An assembled battery was produced in the same manner as in Example 3.

  The production conditions and test results similar to those in Example 3 are shown in Table 1.

Comparative Example 1
A parallel structure battery similar to that of Example 1 was used except that there was no connection of each layer. However, in the comparative example 1, it was set as the specification which made distance of the gravity center longer than the long and short side length of a bipolar battery and a general battery group.

  Specifically, a positive electrode material containing a Li—Mn-based composite oxide was applied at a thickness of 30 μm on one side of a SUS foil (thickness: 20 μm) as a current collector to form a positive electrode layer. After that, a negative electrode layer was formed by applying a negative electrode material containing hard carbon as an amorphous carbon material to a thickness of 30 μm on the opposite surface of the SUS foil on which the positive electrode layer was formed, thereby forming a bipolar electrode.

  The precursor of the cross-linked gel electrolyte was infiltrated into a PET non-woven fabric separator (about 30 μm thick), and was layered on the bipolar electrode obtained previously. Further, a similar bipolar electrode was stacked thereon to constitute a 12-layer (12 electrode unit) bipolar battery.

  An Al positive electrode tab (200 μm thickness: width 100 mm) is vibration welded to the positive electrode side (end portion of the outermost layer current collector) of the 12-layer bipolar electrode, and is attached to the negative electrode side (end portion of the outermost layer current collector). Vibrated and welded a negative electrode tab made of Cu (thickness of 200 μm: width of 100 mm). Further, SUS (10 μm thickness: width 5 mm) was taken out from the side different from the electrode tab taking-out side of each single cell layer as the detection tab (see FIG. 2A). The entire power generating element (battery body) having the tab-integrated 12-layer bipolar electrode was sealed with a laminate material (the appearance was similar to the front view of FIG. 2A).

  This 12-layer (12 cells) bipolar battery was heated and crosslinked at about 80 ° C. for about 2 hours to produce a 12-layer bipolar battery.

  A general battery was fabricated using the same material as that used in the bipolar battery. That is, a positive electrode material containing a Li—Mn composite oxide was applied to both surfaces of a SUS foil (thickness 20 μm) as a positive electrode current collector with a thickness of 30 μm on one side to form a positive electrode layer. A negative electrode material containing hard carbon as an amorphous carbon material was applied to both surfaces of a SUS foil (thickness 20 μm) as a negative electrode current collector with a thickness of 30 μm on one side to form a positive electrode layer. A power generation element (battery body) was formed by sandwiching a cross-linked gel electrolyte precursor in a PET nonwoven fabric separator (about 30 μm thick) between the positive electrode and the negative electrode. The entire power generation element (battery body) was sealed with a laminate material. The obtained general battery was heated and crosslinked at about 80 ° C. for about 2 hours to produce a general battery having 10 positive electrodes and 11 negative electrodes. 12 electrode tabs of the general battery were directly connected by vibration welding. In this comparative example, the detection tab of the bipolar battery was not connected for each battery unit (see FIG. 6).

  The distance between the center of gravity of the bipolar battery and the center of the general battery group was arranged so as to be approximately the intermediate value between the long and short sides of the bipolar battery and the short and short sides of the general battery group, as in Example 1.

  After the assembled battery was configured as described above, the battery was inserted into an aluminum case, and the assembled battery having the appearance of one case 55 in FIG. 12 (the basic configuration inside the assembled battery case was the same as that in FIG. 1. However, the arrangement of the general battery group was the same as in FIG.

  Basic structure (structure) inside the assembled battery case, the number of stacked bipolar electrodes used to manufacture the bipolar battery, the number of series of general battery groups, the tab cross-sectional area ratio (total cross-sectional area of positive and negative electrode tabs: detection tab + connection ( Table 1 below shows the cross-sectional area)), the positive electrode active material, and the negative electrode active material.

  Further, the obtained assembled battery was measured for the distance between the centers of gravity, the capacity variation, and the average attenuation amount by the test method described below. The obtained results are shown in Table 1 below.

  The production conditions and test results similar to those of Example 1 are shown in Table 1, and a diagram showing the frequency-vibration transmissibility characteristics obtained by measuring the average reduction amount is shown in FIG.

Test method (1) Measurement of capacity variation The 1C CC charge / discharge cycle test was conducted 1000 times with the assembled batteries of Examples and Comparative Examples set to an upper limit of 50V and a lower limit of 36V. At that time, the voltage variation between the respective layers was compared with the initial voltage variation, and the change rate of the standard deviation was evaluated to be up to 1.2 times. When it exceeded 1.2 times, it was set as x.

(2) Measurement of average reduction amount An acceleration pickup is set at the approximate center of the assembled battery obtained by the method of each of the above examples and comparative examples, and a vibration spectrum of the acceleration pickup is measured when hammered by an impulse hammer. did. The setting method conformed to JIS B 0908 (vibration and shock pickup calibration method / basic concept). The measured spectrum was analyzed by an FFT analyzer and converted to frequency and acceleration dimensions. The obtained frequency was averaged and smoothed to obtain a vibration transmissibility spectrum. The average of the acceleration spectrum up to 10 to 300 Hz was defined as the vibration average value.

  The comparison reference was the vibration average value of the spectrum of the conventional example, and the ratio to the vibration average value of each reference was the average reduction amount.

  Therefore, when the average attenuation amount is 0%, the vibration average values of the conventional example and the embodiment are equivalent, indicating that no attenuation occurs. When the average attenuation amount is 30%, the embodiment is an example of the conventional example. It shows that the vibration average value of was reduced by 30%.

  In addition, the diagram which shows the characteristic of the frequency-vibration transmissibility in the assembled battery of Example 2 obtained by the said test was shown as "invention structure" in FIG. Similarly, a diagram showing the frequency-vibration transmissibility characteristics of the assembled battery of Comparative Example 1 obtained by the above test is shown as “conventional structure” in FIG.

(3) Center-of-gravity distance requirement A case where the distance between the center of gravity of the bipolar battery and the center of the general battery group obtained by the method of each of the above examples and comparative examples is shorter than the long and short side lengths of the bipolar battery and the general battery group. did. The case where the distance of the center of gravity is longer than the long and short side lengths of the bipolar battery and the general battery group is defined as x.

1 is a schematic plan view schematically showing a typical embodiment of a battery pack of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the bipolar battery of Embodiment 1 used for the assembled battery of this invention, (a) is the front view, (b) is the side view, (c) is the AA cross section of (a). The figure is shown. FIG. 3 is a schematic cross-sectional view of the inside of the battery, schematically showing the internal structure and tab connection structure of the bipolar secondary battery of FIG. It is an external view of the bipolar secondary battery of Embodiment 2 used for the assembled battery of this invention, (a) is the front view, (b) is the side view, (c) is the AA sectional drawing. Is shown. FIG. 5A shows a configuration in which the configuration of the assembled battery in FIG. 1 is simplified, and each layer inside the battery on the bipolar battery side is connected in series, and each general battery on the general battery group side is connected in series. A schematic diagram schematically showing a state in which general series connection tabs for each series of general batteries having the same potential level as the detection tab on the bipolar battery side are electrically coupled together. FIG. 5B is a graph showing changes in the current values on the bipolar battery side and the general battery group side with time transition after large current discharge at the measurement point in FIG. . FIG. 6 (a) shows a general series connection for each series of general batteries at the same potential level as the detection tab on the bipolar battery side in the configuration of the assembled battery of FIG. 5 (a) for comparison with the assembled battery of the present invention. It is the schematic drawing which represented typically a mode that it was set as the assembled battery, without electrically coupling a tab. FIG. 6B is a graph showing changes in current values on the bipolar battery side and the general battery group side with time transition after large current discharge at the measurement point in FIG. 6A. . In the assembled battery of FIG. 1, the distance between the center of gravity on the surface of the bipolar battery and the center of gravity of the projected outline of the general battery group is in the range of the short side length and the short side length of the short side of the bipolar battery or the general battery group outline. It is the schematic plan view which represented typically the embodiment of the vibration proof structure formed so that it may become. It is the plane schematic diagram which represented typically other typical embodiment of the assembled battery of this invention. 8 shows an embodiment of an assembled battery in which the projected area of the battery is reduced by folding the assembled battery of FIG. 8 at a dotted line portion so as to be superimposed on the bipolar battery. It is the schematic plan view which represented the mode before piling up typically. FIG. 7 shows the vibration state of the assembled battery (invention structure) with the connection in FIG. 7 and the assembled battery (conventional structure) in which the detection tab and the general series connection tab are not electrically coupled (no connection) in the assembled battery in FIG. It is a graph of the characteristic of a frequency-vibration transmissibility. It is the schematic which represented the mode of the assembled battery formed by accommodating the basic composition of the assembled battery shown in FIG. 7 in an assembled battery case. FIG. 12 is a schematic diagram of a composite battery pack in which six battery packs each having six basic configurations of the battery pack shown in FIG. 9 housed in the battery pack case shown in FIG. 11 are connected in parallel. It is the schematic which represented the mode that the composite assembled battery was mounted in the vehicle. 1 is a schematic cross-sectional view schematically showing the overall structure of a general battery. 1 is a schematic cross-sectional view schematically showing the entire structure of a bipolar battery.

Explanation of symbols

1 battery pack,
2 power generation elements,
3 Bipolar secondary battery,
5 General battery,
7 General battery group,
9 Voltage detection tab (detection tab),
11 Tab connection part (general series connection tab) for each series of general batteries
12 Busbar,
13 Positive electrode tab of a bipolar secondary battery,
15 Bipolar secondary battery negative electrode tab,
17 + terminal (positive electrode tab) of general battery group,
19 -terminal (negative electrode tab) of the general battery group,
21 Connection,
22 Polymer metal composite film,
23 sealing part,
24 single cell layer (cell),
25 Current collector,
26 positive electrode layer,
27 negative electrode layer,
28 bipolar electrodes,
29 electrolyte layer,
31 General battery,
32 Battery exterior material,
33 positive electrode current collector,
34 positive electrode active material layer,
35 electrolyte layer,
36 negative electrode current collector,
37 negative electrode active material layer,
38 Power generation elements,
39 Positive electrode (terminal) lead,
40 Negative electrode (terminal) lead,
41 bipolar battery,
42 current collector,
43 positive electrode active material layer,
44 negative electrode active material layer,
45 bipolar electrodes,
45a, the uppermost electrode of the electrode stack,
45b, the bottom electrode of the electrode stack,
46 electrolyte layer,
47 electrode laminate (bipolar battery body, power generation element),
48 positive lead,
49 Negative lead,
50 Battery exterior material (exterior package),
52 external elastic body,
54 detection tab terminal,
55 battery pack case,
59 Terminal lead,
62 positive terminal,
64 negative terminal,
70 composite battery pack,
72 assembled battery positive terminal connection plate,
74 assembled battery negative terminal connection plate,
76 connecting plate,
77 fixing screws,
80 electric car,
L, La, Lb Distance between the center of gravity of the bipolar battery and the center of gravity of the general battery group,
L ₁ long short side length,
L ₂ , L ₂ short short side length,
G ₁ bipolar secondary battery center of gravity,
G ₂ , G ₃ general battery group center of gravity,
S ₁ , S ₂ , S ₃ projected outlines.

Claims (10)

A battery assembly in which two types of batteries in a general battery group in which a bipolar battery and a general battery are connected in series by the number of combinations of positive and negative electrodes of the bipolar battery are in a parallel structure,
The bipolar battery has a detection tab connected to each cell layer configured,
An assembled battery, wherein a tab connecting portion for each series of general batteries having the same potential level as that of the detection tab is electrically coupled.   The total cross-sectional area of the positive electrode and the negative electrode tab of the bipolar battery has at least twice the cross-sectional area of the connection between the detection tab and the connection tab for each series connection of the general battery. Battery pack.   The assembled battery according to claim 1 or 2, wherein the tabs of the general battery are joined by vibration welding.   The Young's modulus of the material of all connections of the detection tab and the connection tab for each series connection of the general battery is equal to or less than the Young's modulus of the detection tab and the connection tab material for each series connection of the general battery. The assembled battery according to any one of claims 1 to 3.   The distance between the center of gravity on the surface of the bipolar battery and the center of gravity of the projected outer shape of the general battery group is shorter than the length of the short side of the outer shape of the bipolar battery or the general battery group. The assembled battery according to any one of the above.   The assembled battery according to claim 1, wherein at least a part of the general battery group overlaps the surface of the bipolar battery.   The assembled battery according to claim 1, wherein the positive electrode active material of the bipolar battery is a Li—Mn composite oxide.   The assembled battery according to any one of claims 1 to 7, wherein a negative electrode active material of the bipolar battery is selected from a crystalline carbon material and an amorphous carbon material.   A composite assembled battery comprising at least two or more assembled batteries according to claim 1 connected in series, in parallel, or in series and parallel. A vehicle comprising the assembled battery according to claim 1 or the composite assembled battery according to claim 9.

Images