Lithium-ion battery device for a vehicle

Abstract

Lithium-ion battery device for a vehicle, comprising: an enclosure (11); a battery cell (12) which is housed inside the enclosure (11); and an adjacent element that is adjacent to the battery cell (12) and is provided on a rear side thereof in a longitudinal direction of the vehicle, wherein the battery cell (12) comprises: a cell housing (25), an electrode body (30) which is housed inside the cell housing (25), and a pair of terminals (26A, 26B) which are provided on a surface (25f) of the cell housing (25), wherein the cell housing (25) includes a first main surface and a second main surface, each having a larger area than the surface (25f) on which the pair of terminals (26A, 26B) are provided, wherein the first main surface and the second main surface face each other in the longitudinal direction of the vehicle, wherein the second main surface is arranged on the rear side of the first main surface in the longitudinal direction of the vehicle, at least two gap-forming sections (15), each having a smaller area than the area of ​​the second main surface and having a specified thickness (H) in the longitudinal direction of the vehicle, are arranged between the second main surface and the adjacent element, wherein the at least two gap-forming sections (15) are spaced apart from each other in an intermediate connection direction of the battery cell (12), and wherein the battery cell (12) further comprises a pair of collectors (33, 34), which connect the electrode body (30) and the pair of terminals (26A, 26B) inside the cell housing (25), and the two gap-forming sections (15) are positioned such that the two gap-forming sections (15) do not overlap with the pair of collectors (33, 34) when viewed in a longitudinal direction of the vehicle, and wherein the first main surface of the cell housing (25) has a concave groove (27) positioned between the two gap-forming sections (15) and extending in a direction perpendicular to the intermediate connection direction of the battery cell (12).

Description

[0001] The present invention relates to a lithium-ion battery device for a vehicle.

[0002] A lithium-ion battery is a secondary battery that charges and discharges by transferring lithium ions between a positive and a negative electrode. Its characteristics include high energy density and high charge / discharge efficiency. These lithium-ion batteries are commonly used as power sources for vehicles, particularly electric and hybrid vehicles.

[0003] However, measures to improve safety can be implemented on lithium-ion batteries because a flammable organic solvent is used as the electrolyte. In particular, it is necessary to implement sufficient measures for lithium-ion batteries installed in vehicles to prevent them from simply breaking in a vehicle impact. Accordingly, modern vehicles incorporate measures such as the use of a battery housing with a rigid structure, or similar solutions, to ensure enhanced safety.

[0004] The published Japanese patent JP 4 714 988 B2 proposes a structure that prevents the temperature of a battery from becoming excessively high. Specifically, a battery device disclosed in this patent document comprises several battery cells in the form of flat plates arranged in a row in a thickness direction (referred to in this document as a battery module), and an enclosure (a lower housing and a battery cover) that houses the battery cells. An air inlet duct, through which air supplied by an air-feed fan is introduced, and an air outlet duct, through which air is discharged, are connected to the enclosure. The battery cells are mounted inside the enclosure such that they are spaced apart from one another.The air drawn into the housing by the air intake fan passes through a gap between adjacent battery cells and is then exhausted from the housing. This air, flowing inside the housing, cools the battery cells, preventing them from overheating. This, in turn, improves the safety of the battery system.

[0005] In connection with the present and other inventions, and in order to further improve the safety of a lithium-ion battery device, a phenomenon that occurs when a load is introduced into the battery cells has been analyzed. This phenomenon manifests itself in the damage of an electrode body inside each cell, thereby undesirably causing a short circuit. Accordingly, analyses were carried out with the aim of preventing such damage to the electrode body (short circuit). The results showed that even when a load is introduced that is sufficiently high to deform the cell casing forming the contour of the battery cell, the electrode body inside the cell casing may not be damaged uniformly.In other words, it is possible to deform the cell casing while protecting the electrode body from damage. However, if the cell casing is compressed to such an extent that its thickness is significantly reduced, damage to the electrode body may easily occur. Even if the cell casing is deformed in such a way that its thickness is essentially maintained, damage to the electrode body may not necessarily occur.

[0006] In this context, there is room for improvement in the battery device disclosed in the aforementioned patent document. Specifically, because the battery cells disclosed in the patent document are arranged in a row in the thickness direction such that they are spaced apart from one another, if a load is applied to a battery cell positioned at one end, the cell receiving the load will be pressed against and subsequently crushed against the adjacent battery cell. This presents a problem in that the thickness of the cell casing can be significantly reduced. This significant reduction in thickness (crushing of the cell casing) can damage the electrode body and cause a short circuit.

[0007] DE 11 2015 001 916 T5 describes an electricity storage system comprising a plurality of electricity storage elements, a separating component, a pair of end plates, and a plurality of coupling components. The housing has a flat surface with a first area opposite a positive electrode active material layer and a negative electrode active material layer of a power generating element, and a second area distinct from the first. The separating component is arranged between two electricity storage elements adjacent to each other in the predetermined direction. The pair of end plates is positioned such that it centers the plurality of electricity storage elements in the predetermined direction, thereby exerting a deformation restraint force on the plurality of electricity storage elements.The deformation restraint force acting on the second area is greater than the deformation restraint force acting on the first area.

[0008] US 2019 / 0013500A1 describes a battery module comprising a cell stack body consisting of a plurality of cells stacked in a front-to-back direction and including a front surface, a rear surface, a left surface, a right surface, a top surface, and a bottom surface; a pair of end plates located on the front and rear surfaces of the cell stack body; and a pair of side frames located on the right and left surfaces of the cell stack body. One end of the end plate and one end of the side frame have an overlapping section in which the end of the end plate and the end of the side frame overlap each other when viewed from top to bottom. The overlapping section has a through-hole oriented in the up-and-down direction. A connecting shaft is inserted into the through-hole.

[0009] DE 10 2009 035 463 A1 describes a battery comprising a plurality of flat, essentially plate-shaped individual battery cells. The individual battery cells are stacked to form a cell stack and surrounded by a battery housing. The individual battery cells are designed in a flat frame construction with metallic outer plates and a frame made of insulating material. At least a certain number of the individual battery cells project beyond the outer plates in the direction of the battery housing on at least two of their side edges, at least in sections.

[0010] KR 10 2015 0 124 215 A describes a prismatic secondary battery with enhanced safety, capable of preventing explosion or ignition by causing the prismatic secondary battery to fold symmetrically, ultimately placing it into a safe short-circuit mode. The prismatic secondary battery is folded by an external force applied to it. The prismatic secondary battery comprises an electrode assembly on which an anode plate and a cathode plate are arranged facing each other, a battery casing that houses the electrode assembly in an interior space, and a cap plate combined therewith. The upper end of the battery casing seals an opening formed at the top of the casing and includes a folding groove formed in a specific area.

[0011] The present invention was made under the circumstances described above. One object of the present invention is to provide a lithium-ion battery device for a vehicle that can prevent damage to the electrode body in a case where a load is introduced into the battery cell.

[0012] The problem is solved by a lithium-ion battery device for a vehicle according to the independent claims of the present invention. Preferred embodiments of the present invention are the subject of the further dependent claims.

[0013] A first aspect of the present invention is a lithium-ion battery device for a vehicle, comprising: an enclosure, a battery cell located inside the enclosure, and an adjacent element located adjacent to the battery cell and on a rear side thereof substantially in a vehicle longitudinal direction (direction approximately running in the longitudinal direction of the vehicle), wherein the battery cell comprises: a cell housing, an electrode body located inside the cell housing, and terminals arranged in pairs.a pair of terminals provided on a surface of the cell housing, wherein the cell housing comprises a first main surface and a second main surface, each having a larger area than the surface on which the pair of terminals are provided and oriented substantially in the longitudinal direction of the vehicle, wherein the second main surface is located on the rear side of the first main surface substantially in the longitudinal direction of the vehicle, wherein at least two gap-forming sections, each having a smaller area than the area of ​​the second main surface and having a specified thickness in the longitudinal direction of the vehicle, are arranged between the second main surface and the adjacent element, and wherein the at least two gap-forming sections are spaced apart substantially in an intermediate terminal direction of the battery cell.

[0014] According to the first aspect of the present invention, since the two gap-forming sections, which are spaced apart from each other in the intermediate connection direction, are arranged between the second main surface, which is located on the rear side in the longitudinal direction of the vehicle, and the adjacent element, which is adjacent to the second main surface, a space formed between the two gap-forming sections can be used as a space that allows bending deformation of the cell housing. In a frontal vehicle impact, for example, the impact load is introduced from the front of the vehicle into the first main surface of the cell housing, which is positioned at the front of the vehicle, such that a bending moment occurs that causes the cell housing to bend rearward about the two gap-forming sections, which serve as the center of rotation.This bending moment acts in such a way that the cell housing is deformed in an arc, with a central section of the cell housing, located between the two gap-forming sections, being displaced rearward. The space provided between the two gap-forming sections acts as a space that allows bending of the central section of the cell housing, thus promoting the bending deformation of the cell housing. Since the impact energy is sufficiently absorbed by the bending deformation of the cell housing, it prevents the cell housing from being deformed to such an extent that it is severely compressed in the thickness direction. This prevents damage to the electrode body inside the cell housing and a short circuit caused by such damage.This means that, according to the present invention, in a comparatively simple manner, in which the several gap-forming sections are arranged between the rear surface (second main surface) of the cell housing and the adjacent element provided adjacent to this surface, the deformation of the cell housing can be controlled or regulated in such a way that the thickness of the cell housing is not greatly reduced (squashed), thereby efficiently preventing the occurrence of damage to the electrode body inside the cell housing and a short circuit caused by the damage.

[0015] According to the first aspect of the present invention, the first main surface of the cell housing has a concave groove positioned between the two gap-forming sections and extending in a direction substantially perpendicular to the intermediate connection direction of the battery cell.

[0016] According to the present embodiment, the concave groove formed on the first main surface can serve as the starting point for the aforementioned bending deformation of the cell housing. This improves the controllability of the cell housing deformation to such an extent that the possibility of crushing the cell housing (significant reduction in thickness) can be reduced, thereby effectively preventing damage (short circuit) to the electrode body inside the cell housing.

[0017] According to the first aspect of the present invention, the battery cell further comprises collectors arranged in pairs or a pair of collectors which connect the electrode body and the terminals arranged in pairs inside the cell housing, wherein the two gap-forming sections are positioned such that the two gap-forming sections with the collectors arranged in pairs do not overlap when viewed substantially in the longitudinal direction of the vehicle.

[0018] According to this embodiment, a situation in which the collectors and the cell housing contact each other when a load is applied from the front of the vehicle can be avoided. This means that when a load is applied from the front of the vehicle, a problem arises in that the second main surface of the cell housing can be partially deformed by absorbing a reaction force from the gap-forming sections. However, according to this embodiment, since the gap-forming sections are positioned such that they do not overlap with the collectors when viewed in the longitudinal direction of the vehicle, a significant reduction in the distance between the second main surface and the collectors is avoided, even if the reaction force from the gap-forming sections has caused the second main surface of the cell housing to be partially deformed towards the first main surface.This prevents contact between the cell housing and the collectors, and a short circuit caused by this contact.

[0019] In a further embodiment of the first aspect of the present invention, the lithium-ion battery device for a vehicle may further comprise: an additional battery cell provided on the rear side of the battery cell substantially in the longitudinal direction of the vehicle, and an additional adjacent element provided adjacent to the additional battery cell and on the rear side thereof substantially in the longitudinal direction of the vehicle, wherein an additional gap-forming section having a smaller thickness in the longitudinal direction of the vehicle than the thickness of the two gap-forming sections in the longitudinal direction of the vehicle may be provided between the additional battery cell and the additional adjacent element.

[0020] If a load is applied to the multiple battery cells arranged in a row along the vehicle's length from the front, the foremost battery cell tends to deform the most, with the degree of deformation gradually decreasing in the other battery cells located behind the aforementioned cell. This means that the impact energy is absorbed sufficiently by the foremost battery cell that the rear battery cell (the additional battery cell) is less affected by the impact, thus reducing the degree of deformation of the battery cell located at the rear of the vehicle.According to this embodiment, since the thickness of the additional gap-forming section, which is positioned on the back of the additional battery cell, is chosen to be small, it is possible to prevent the battery device from being built inappropriately large, while maintaining the previously described damage-preventing effect of the electrode body.

[0021] In a further embodiment of the first aspect of the present invention, a vehicle is provided which includes the lithium-ion battery device. When provided in a vehicle, the lithium-ion battery device is arranged such that the first main surface of the cell housing faces the front of the vehicle.

[0022] A second aspect of the present invention is a lithium-ion battery device for a vehicle, comprising: an enclosure, a battery cell located inside the enclosure, and an adjacent element located adjacent to the battery cell and on a front face thereof substantially in a longitudinal direction of the vehicle (direction approximately in the longitudinal direction of the vehicle), wherein the battery cell comprises: a cell housing, an electrode body located inside the cell housing, and paired terminals; a pair of terminals provided on a surface of the cell housing, wherein the cell housing comprises a first principal surface and a second principal surface, each having a larger area than the area of ​​the surface on which the pair of terminals is provided and which point substantially towards each other in the longitudinal direction of the vehicle.wherein the second main surface is arranged on the front of the first main surface substantially in the longitudinal direction of the vehicle, wherein at least two gap-forming sections, each having a smaller area than the area of ​​the second main surface and having a specified thickness in the longitudinal direction of the vehicle, are arranged between the second main surface and the adjacent element, wherein the at least two gap-forming sections are spaced apart from each other substantially in an intermediate connection direction of the battery cell.

[0023] According to this second aspect of the present invention, the strength against a load introduced from the rear of the vehicle, for example, against an impact load introduced from the rear of the vehicle in a rear-end collision, can be improved. This means that, because the two gap-forming sections, which are spaced apart from each other in the intermediate connection direction, are arranged between the second main surface, which is located on the front in the longitudinal direction of the vehicle, and the adjacent element, which is adjacent to the second main surface, when a load introduced from the rear of the vehicle acts on the first main surface of the cell housing positioned on the rear of the vehicle, the deformation of the cell housing is controlled in such a way as to...It can be regulated so that the thickness of the cell housing is not significantly reduced, which is also the case with the battery device described above in the first aspect of the present invention, so that damage to the electrode body inside the cell housing (short circuit) can be prevented.

[0024] According to the second aspect of the present invention, the first main surface of the cell housing has a concave groove positioned between the two gap-forming sections and extending in a direction substantially perpendicular to the intermediate connection direction of the battery cell.

[0025] According to this embodiment, the controllability of the deformation described above can be further improved by using the concave groove as the starting point of the deformation.

[0026] According to the second aspect of the present invention, the battery cell further comprises collectors arranged in pairs or a pair of collectors which connect the electrode body and the terminals arranged in pairs inside the cell housing, wherein the two gap-forming sections are positioned such that the two gap-forming sections with the collectors arranged in pairs do not overlap when viewed substantially in the longitudinal direction of the vehicle.

[0027] According to this embodiment, a situation can be avoided in which the collectors and the cell housing contact each other when a load is applied from the rear of the vehicle.

[0028] In a further embodiment of the second aspect of the present invention, the lithium-ion battery device for a vehicle may further comprise: an additional battery cell provided on the front of the battery cell in the longitudinal direction of the vehicle, and an additional adjacent element provided adjacent to the additional battery cell and on the rear of the latter substantially in the longitudinal direction of the vehicle, wherein an additional gap-forming section having a smaller thickness in the longitudinal direction of the vehicle than the thickness of the two gap-forming sections in the longitudinal direction of the vehicle may be provided between the additional battery cell and the additional adjacent element.

[0029] According to the present embodiment, it is possible to prevent the battery device from being built unsuitably large, while maintaining the previously described damage-preventing effect of the electrode body when a load is applied from the rear of the vehicle.

[0030] In a further embodiment of the second aspect of the present invention, a vehicle comprising the lithium-ion battery device is provided. When installed in a vehicle, the lithium-ion battery device is arranged such that the first main surface of the cell housing faces the rear of the vehicle.

[0031] A third aspect of the present invention is a lithium-ion battery device for a vehicle, comprising: an enclosure, a battery cell located inside the enclosure, and an adjacent element located adjacent to the battery cell and on an inner surface thereof substantially in a vehicle width direction (direction approximately in the width direction of the vehicle), wherein the battery cell comprises: a cell housing, an electrode body located inside the cell housing, and paired terminals.a pair of terminals provided on a surface of the cell housing, wherein the cell housing comprises a first main surface and a second main surface, each having a larger area than the area of ​​the surface on which the pair of terminals are provided and which point substantially towards each other in the vehicle width direction, wherein the second main surface is arranged on the inside of the first main surface substantially in the vehicle width direction, wherein at least two gap-forming sections, each having a smaller area than the area of ​​the second main surface and having a specified thickness in the vehicle width direction, are arranged between the second main surface and the adjacent element, and wherein the at least two gap-forming sections are spaced apart from each other substantially in an intermediate terminal direction of the battery cell.

[0032] According to the third aspect of the present invention, the strength against a load introduced from the outside of the vehicle, for example against an impact load introduced from the outside of the vehicle in a side-impact collision, can be improved. This means that, because the two gap-forming sections, which are spaced apart from each other in the intermediate connection direction, are arranged between the second main surface, which is located on the inside in the vehicle width direction, and the adjacent element, which is adjacent to the second main surface, when a load introduced from the outside of the vehicle acts on the first main surface of the cell housing positioned on the outside of the vehicle, the deformation of the cell housing is controlled in such a way as to...It can be regulated so that the thickness of the cell housing is not significantly reduced, which is also the case with the battery device described above in the first and second aspects of the present invention, so that damage to the electrode body inside the cell housing (short circuit) can be prevented.

[0033] According to the third aspect of the present invention, the first main surface of the cell housing has a concave groove positioned between the two gap-forming sections and extending in a direction substantially perpendicular to the intermediate connection direction of the battery cell.

[0034] According to the present invention, the controllability of the deformation described above can be improved by using the concave groove as the starting point of the deformation.

[0035] According to the third aspect of the present invention, the battery cell further comprises collectors arranged in pairs or a pair of collectors which connect the electrode body and the paired terminals arranged inside the cell housing, wherein the two gap-forming sections are positioned such that the two gap-forming sections with the paired collectors do not overlap when viewed substantially in the vehicle width direction.

[0036] According to this embodiment, a situation can be avoided in which the collectors and the cell housing contact each other when a load is introduced from the outside of the vehicle.

[0037] In a further embodiment of the third aspect of the present invention, the lithium-ion battery device for a vehicle may further comprise: an additional battery cell provided on the outside of the battery cell substantially in the vehicle width direction, and an additional adjacent element provided adjacent to the additional battery cell and on the inside thereof in the vehicle width direction, wherein an additional gap-forming section having a smaller thickness in the vehicle width direction than the thickness of the two gap-forming sections in the vehicle width direction may be provided between the additional battery cell and the additional adjacent element.

[0038] According to the embodiment, it can be prevented that the battery device is built unsuitably large, while the previously described damage-preventing effect of the electrode body when a load acts from the rear of the vehicle is retained.

[0039] In a further embodiment of the third aspect of the present invention, a vehicle comprising the lithium-ion battery device is provided. When provided in the vehicle, the lithium-ion battery device is arranged such that the first main surface of the cell housing faces the outside of the vehicle.

[0040] The present invention is better understood from the following description, which is based on the accompanying drawing. Fig. Figure 1 is a diagram illustrating a schematic structure of a vehicle in which a lithium-ion battery device according to a first embodiment of the present invention is used. Fig. Figure 2 is a perspective view showing the exterior of the lithium-ion battery device. Fig. Figure 3 is a perspective exploded view to illustrate the structure of the lithium-ion battery device. Fig. Figure 4 is a plan view showing the interior of the lithium-ion battery device. Fig. Figure 5 is a perspective view showing the exterior of a battery cell. Fig. Figure 6 is a transparent perspective view showing the internal structure of the battery cell. Fig. Figure 7 is a sectional view showing the structure of an electrode body. Fig. Figure 8 is a rear view of the battery cell. Fig. Figure 9 is an explanatory diagram illustrating the type of deformation that occurs when a load is applied to the battery cell. Fig. Figure 10 is a plan view to show the size of each part of the battery cell. Fig. 11A and Fig. Figure 11B shows results of a simulation that was carried out to demonstrate the operational processes and effects of the present invention, wherein Fig. 11A shows a relationship between rib spacing and electrode body stress and Fig. Figure 11B shows a relationship between a groove width and the electrode body stress. Fig. 12 is a plan section view accordingly Fig. 4 to explain a second embodiment of the present invention. Fig. 13 is a plan section view accordingly Fig. 4 to explain a third embodiment of the present invention. Fig. 14 is a plan section view accordingly Fig. 4 to explain a fourth embodiment of the present invention. Fig. 15 is a rear view accordingly Fig. 8 to explain a modification of the first embodiment. Fig. 16 is a rear view accordingly Fig. 8 to explain a further modification of the first embodiment. (1) First embodiment Schematic structure of a vehicle

[0041] Fig. Figure 1 is a diagram illustrating a schematic structure of a vehicle in which a lithium-ion battery device 1 according to a first embodiment of the present invention is used. As shown in this figure, the vehicle is a four-wheeled motor vehicle in which the lithium-ion battery device 1 (hereinafter simply referred to as battery device 1) is used. The vehicle comprises a vehicle body 2, several (four) wheels 3 for supporting the vehicle body 2, an engine 4, for example a four-stroke internal combustion engine, which is installed as a power source to drive the wheels 3 (in other words, to propel the vehicle), a transmission 5 for transmitting rotational force from the engine 4, and a radiator 6 for cooling a coolant that is introduced into the engine 4 by heat exchange with the outside air.

[0042] The battery device 1 is a rechargeable / dischargeable secondary battery. This means that the battery device 1 functions as a power source, supplying power for the operation of various electrical parts of the vehicle, as well as a charger, which is charged by the power generated by an electric generator, such as an alternator, attached to the motor 4.

[0043] The battery assembly 1, the motor 4, the transmission 5, and the radiator 6 are housed in an engine compartment R, which is provided at the front of the vehicle body 2. The battery assembly 1 and the transmission 5 are positioned so close to each other that the battery assembly 1 is located on the upper rear side of the transmission 5. In other words, the battery assembly 1 is arranged such that its front section is located directly above the rear section of the transmission 5.

[0044] In this description, "forward or front" and "backward or rear" are used as terms to describe directions. This means that, in a forward direction of movement of a vehicle, the advancing side of the vehicle (the side that is facing forward) is the side facing the vehicle. Fig. In example 1, the side of the vehicle body 2 (directed from the center of the vehicle body 2 towards the engine compartment R) is referred to as "forward" or "front" or "front(s)", whereas a forward-moving side of the vehicle in a reverse direction (the side that is facing forward in the vehicle) is referred to as "forward" or "front" in the vehicle body 2, whereas in a reverse direction of a vehicle, the advancing side of the vehicle (the side that is facing forward in the vehicle body 2) is referred to as "forward" or "front" in the vehicle body 2, and "front" in the vehicle body 2, is referred to as "front ... Fig. In the example shown in Figure 1 (directed from the engine compartment R towards the center of the vehicle body 2), the direction is described as "backwards" or "rear" or "behind". Since the directional terms "forward" or "front" or "front" and "backwards" or "rear" refer to a vehicle, the terms "vehicle front" and "vehicle rear" are also used in this description. In some cases, however, the simpler expressions "front" and "rear" are used, omitting the word "vehicle". The meaning remains unchanged.

[0045] Furthermore, the term "vehicle width direction" refers to a direction perpendicular to the vehicle's longitudinal direction in a plan view. The direction term "vertical direction" refers to a direction perpendicular to both the vehicle's longitudinal and vehicle width directions, where the side pointing from a ground surface contacting wheel 3 towards a point is called the "upper" or "upward" side, and the opposite side is called the "lower" or "downward" side. Detailed structure of the battery device

[0046] Fig. Figure 2 is a perspective view showing the exterior of the battery device 1. Fig. Figure 3 is a perspective exploded view to show a structure of the battery device 1, and Fig. Figure 4 is a plan view illustrating the interior of the battery device 1. As shown in these figures, the battery device 1 comprises a housing 11, several battery cells 12, several intermediate cell plates 13, a base plate 14, several vertical ribs 15, and external terminals 16A and 16B arranged in pairs. The battery cells 12, the intermediate cell plates 13, the base plate 14, and the vertical ribs 15 are located inside the housing 11. In the present embodiment, external terminal 16A is a positive terminal, while external terminal 16B is a negative terminal.Should a specific differentiation between the two be necessary in the following, the external connection 16A will be referred to as external positive electrode connection 16A, while the external connection 16B will be referred to as external negative electrode connection 16B.

[0047] The enclosure 11 comprises an enclosure body 21 and an enclosure cover 22. The enclosure body 21 is a box-like element with an open upper surface and includes a lower surface 21e, which has a rectangular shape in a plan view, and a front surface 21a, a rear surface 21b, and paired side surfaces 21c, 21d, each extending upwards from a circumferential edge of the lower surface 21e. The front surface 21a and the rear surface 21b are arranged such that they face each other substantially in the longitudinal direction of the vehicle, with the front surface 21a being positioned on the front of the vehicle at the rear surface 21b. When located in a vehicle, the front surface 21a of the enclosure body 21 is specifically arranged such that it faces substantially towards the front of the vehicle.The paired side surfaces 21c, 21d are oriented such that they essentially face each other in the direction of the vehicle's width. The housing cover 22 is attached to the housing body 21 in such a way that an opening in the upper surface of the housing body 21 is closed. The housing 11 (housing body 21 and housing cover 22) can be made of a high-strength metal material, a fiber-reinforced resin, or the like, so that the element has a comparatively high strength.

[0048] The paired external connections 16A, 16B (external positive electrode connection 16A and external negative electrode connection 16B) are provided such that they project substantially upwards from the housing cover 22 at two different points, which are substantially spaced apart from each other in the vehicle width direction.

[0049] The multiple battery cells 12 are arranged such that they are essentially in a row in the longitudinal direction of the vehicle inside the housing 11. In the present embodiment, four battery cells 12 are arranged inside the housing 11. Each battery cell 12 is a so-called square-type battery cell comprising a cell housing 25, which is an essentially flat rectangle (plate-shaped body) with a dimension (thickness) in the longitudinal direction of the vehicle that is smaller than a dimension in the width direction of the vehicle, and pairs of terminals 26A, 26B, which project substantially upwards from the cell housing 25. In the present embodiment, terminal 26A is a positive terminal, while terminal 26B is a negative terminal.If a specific distinction is to be made between the two in the following, terminal 26A will be referred to as positive electrode terminal 26A, while terminal 26B will be referred to as negative electrode terminal 26B.

[0050] The multiple battery cells 12 are housed inside the enclosure 11 in a position where the battery cells face each other, leaving a small gap between them in one thickness direction (longitudinal direction). In other words, the multiple battery cells 12 are arranged in a row in the longitudinal direction inside the enclosure 11 in a position where the respective main surfaces of the multiple cell housings 25 (front surfaces 25a and rear surfaces 25b, which will be described below) are parallel to the front surface 21a and the rear surface 21b of the enclosure body 21.When provided on a vehicle, the front surfaces 25a (first main surfaces) of the cell housings 25 can be arranged such that they point substantially towards the front of the vehicle, while the rear surfaces 25b (second main surfaces) of the cell housings 25 can be arranged such that they point substantially towards the rear of the vehicle.

[0051] The base plate 14 electrically connects the respective positive electrode terminals 26A of the multiple battery cells 12 and links the terminals 26A to the external positive electrode terminal 16A. It also electrically connects the respective negative electrode terminals 26B of the multiple battery cells 12 and links the terminals 26B to the external negative electrode terminal 16B. The base plate 14 comprises a busbar that connects the respective positive electrode terminals 26A (negative electrode terminals 26B) of the multiple battery cells 12, a lead or lead-in plate that contacts the external positive electrode terminal 16A (the external negative electrode terminal 16B), and a conductive element that connects the busbar and the lead or lead-in plate. A separate illustration of these components is omitted.

[0052] The multiple intermediate cell plates 13 are arranged between adjacent battery cells 12. In the present embodiment, the three intermediate cell plates 13 are prepared to correspond to the four battery cells 12. The intermediate cell plate 13 can be a resin-based element with a rectangular shape in a longitudinal view. The intermediate cell plate 13 is designed such that its thickness (longitudinally) is sufficiently smaller than that of the battery cell housing 25, and its dimensions in the vehicle width direction and its dimensions in the vertical direction are essentially the same as those of the battery cell housing 25. The intermediate cell plate 13 serves as an element that provides thermal insulation between the adjacent battery cells 12.

[0053] The multiple vertical ribs 15 are adjacent to each of the battery cells 12 and on the rear side thereof, as in particular in Fig. 4 is provided. Each of the vertical ribs 15 is a rod-shaped element that has a significantly smaller area (size given in width) than the main area (front surface 25a and rear surface 25b, which will be described below) of the cell casing 25 of the battery cell 12 and is essentially oriented in the vertical direction (see also Fig. 3) extends. In other words, the vertical rib 15 has an area whose surface area is significantly smaller than the surface area of ​​the main surface (front surface 25a and rear surface 25b) of the cell housing 25. The vertical rib 25 is configured such that it extends from the vicinity of an upper end of the cell housing 25 to the vicinity of a lower end of the cell housing 25 and has essentially the same vertical dimension as the cell housing 25. Here, the vertical rib 15 corresponds to a "gap-forming section" of the present invention.

[0054] In particular, vertical ribs 15 are provided between the battery cell 12 (with the exception of the battery cell 12 belonging to the rearmost stage) and the intermediate cell plate 13, which is adjacent to the rear of this battery cell 12. Two vertical ribs 15 are provided for each of the battery cells 12. Hereinafter, the other (three) battery cells 12, which are not the battery cell 12 belonging to the rearmost stage, may be referred to as the battery cells 12 belonging to the front three stages, while the several (six) vertical ribs 15 provided corresponding to the battery cells 12 belonging to the front three stages may be referred to as the vertical ribs 15 belonging to the front three stages. Each of the vertical ribs 15 belonging to the front three stages may be attached to a front surface of each of the intermediate cell plates 13 by means of an adhesive or the like.The inter-cell plate 13 and the vertical ribs 15 can of course be formed by integrated resin molding.

[0055] The two vertical ribs 15 are provided between the battery cell 12 belonging to the rearmost stage and the rear surface 21b of the housing 11 (housing body 21), adjacent to the rear of the battery cell 12 belonging to the rearmost stage. Hereinafter, these two vertical ribs 15, that is, the two vertical ribs 15 provided corresponding to the battery cell 12 belonging to the rearmost stage, can be referred to as the vertical ribs 15 belonging to the rearmost stage. The vertical ribs 15 belonging to the rearmost stage can be attached to the rear surface 21b of the housing body 21 by means of adhesive or the like.

[0056] The distance between each of the battery cells 12 belonging to the three stages and the front surface of each of the intermediate cell plates 13 is chosen such that the vertical ribs 15 belonging to the front three stages substantially contact (or are close to contacting) the battery cell 12 positioned on the front of the vertical rib 15. In other words, a gap equal to (or slightly wider than) the thickness of the vertical rib 15 in the longitudinal direction of the vehicle is formed between the intermediate cell plate 13 and the rear-positioned battery cell 12. Accordingly, the vertical rib 15 has a thickness in the longitudinal direction of the vehicle, that is, a thickness equal to the size of the vertical rib 15 in the longitudinal direction of the vehicle.The thickness of the vertical rib 15 can be chosen appropriately, for example a thickness of 2 mm is preferred to prevent the battery device 1 from being built too large.

[0057] A gap is formed between the battery cell 12 belonging to the rearmost stage and the vertical ribs 15 belonging to the rearmost stage. It is preferred that this gap be selected to have the thickness of the vertical ribs 15 or less, and almost zero if achievable. In other words, the gap between the battery cell 12 belonging to the rearmost stage and the vertical ribs 15 belonging to the rearmost stage can be selected such that it essentially corresponds to the thickness of the vertical rib 15 in the longitudinal direction of the vehicle.

[0058] Here, the intermediate cell plate 13, which is provided adjacent to each of the battery cells 15 belonging to the front three stages with the vertical ribs 15 between them, corresponds to an "adjacent element" of the present invention. In other words, the adjacent element can be an intermediate cell plate 13, wherein the intermediate cell plate 13 can be provided adjacent to each of the battery cells 12 belonging to the front three stages. Furthermore, the rear surface 21b of the housing body 21, provided adjacent to the battery cell 12 belonging to the rearmost stage with the vertical ribs 15 between it, can correspond to another "adjacent element" of the present invention. Detailed structure of the battery cell

[0059] Fig. Figure 5 is a perspective view showing the exterior of battery cell 12. As in Fig. 5 and the preceding Fig. As shown in Figure 4, the cell housing 25 of the battery cell 12 has a front surface 25a, a rear surface 25b, a bottom surface 25e, a top surface 25f, and paired side surfaces or a pair of side surfaces 25c, 25d. The front surface 25a and the rear surface 25b are arranged such that they face each other substantially in the longitudinal direction of the vehicle, with the front surface 25a positioned on the front of the vehicle relative to the rear surface 25b. The front surface 25a of the cell housing 25 can be arranged, in particular, such that it faces substantially towards the front of the vehicle, especially when the lithium-ion battery device is installed in a vehicle. The bottom surface 25e and the top surface 25f are arranged such that they face each other vertically, with the top surface 25f positioned above the bottom surface 25e.The paired side surfaces 25c, 25d are designed such that, particularly when the lithium-ion battery device is installed in a vehicle, they point towards each other essentially in the direction of the vehicle's width.

[0060] As previously described, the cell housing 25 is a flat rectangle with a size in the longitudinal direction of the vehicle that is smaller than its size in the width direction. Therefore, the front surface 25a and the rear surface 25b have a larger area than the other surfaces of the cell housing 25. For example, the area of ​​the front surface 25a and the rear surface 25b is significantly larger than the area of ​​the upper surface 25f, on which the connections 26A, 26B are provided. This also applies to the area relationships between the paired side surfaces 25c, 25d and the bottom surface 25e. Here, the front surface 25a corresponds to a "first main surface" of the front of the present invention, while the rear surface 25b corresponds to a "second main surface" of the present invention.

[0061] A concave groove 27, extending substantially in the vertical direction, can be formed at a center point on the front surface 25a of the cell housing 25, located in the direction of the vehicle's width. The concave groove 27 can be configured such that it is set back from a further zone of the front surface 25a relative to the concave groove 27 and extends from an upper end of the front surface 25a to a lower end of the front surface 25a with a constant groove width (a dimension given in the direction of the vehicle's width). In the present embodiment, the battery cell 12 can be arranged such that the orientation of the paired terminals 26A, 26B (hereinafter referred to as the "intermediate terminal direction") corresponds to the vehicle's width direction. In other words, the paired terminals 26A, 26B are arranged along an orientation that substantially corresponds to the vehicle's width direction.In other words, the concave groove 27 is provided such that it extends in a direction perpendicular to the intermediate connection direction in a central section of the front surface 25a of the cell housing 25 given in the intermediate connection direction.

[0062] Fig. Figure 6 is a transparent perspective view illustrating an internal structure of the battery cell 12 (showing an interior part of the battery cell 12 with the cell housing 25 represented by an imaginary line). As shown in this figure, an electrode body 30 is arranged inside the cell housing 25. As shown in Fig. As shown in Figure 7, the electrode body 30 comprises a positive electrode layer 41, a negative electrode layer 42, and a separator 43. The positive electrode layer 41 is a ribbon-like layer produced by bonding an active positive electrode substance to the surface of a base element, such as an aluminum foil. The negative electrode layer 42 is a ribbon-like layer produced by bonding an active negative electrode substance to the surface of a base element, such as a copper foil. The separator 43 is a ribbon-like layer (insulating film) made of porous resin. The separator 43 is impregnated with a non-aqueous electrolyte (produced, for example, by dissolving lithium salt in an organic solvent).Any suitable known substance can be used in the combination of the active positive electrode substance and the active negative electrode substance, as long as the uptake / release of lithium ions is possible.

[0063] The positive electrode layer 41, the negative electrode layer 42, and the separator 43 are wound around an axis extending in the intermediate connection direction and laminated in a flat form. In particular, the positive electrode layer 41, the negative electrode layer 42, and the separator 43 are continuously wound in the form of a single layer such that the separator 43 is arranged between the positive electrode layer 41 and the negative electrode layer 42.

[0064] As in Fig. As shown in Figure 6, pairs of foil bodies 31 and 32 are provided at the two end sections of the electrode body 30 in the intermediate connection direction. The foil body 31 can be configured such that the respective base bodies (e.g., aluminum foils) of the multiple positive electrode layers 41 contained in the electrode body 30 are arranged to extend towards the positive electrode connection 26A, with these extending sections being crimped. The foil body 32 is configured such that the respective base bodies (e.g., copper foils) of the multiple negative electrode layers 42 contained in the electrode body 30 are arranged to extend towards the negative electrode connection 26B, with these extending sections being crimped.

[0065] Collectors 33 and 34, which are present in pairs, can each be attached to the paired foil bodies 31 and 32 by welding or the like. Collector 33 (34) is attached to the foil body 31 (32) in a state in which an upper section of the foil body 31 (32) is positioned between them. Hereinafter, the collector 33 attached to the foil body 31 is referred to as the positive electrode collector 33, while the collector 34 attached to the foil body 32 is referred to as the negative electrode collector 34. The positive electrode collector 33 electrically connects the positive electrode layers 41 of the electrode body 30 and the positive electrode terminal 26A via the foil body 31. The negative electrode collector 34 electrically connects the negative electrode layers 42 of the electrode body 30 and the negative electrode connection 26B via the foil body 31.

[0066] Fig. Figure 8 is a rear view of battery cell 12. Fig. Figure 8 shows the paired vertical ribs 15, which are positioned on the rear side of each of the battery cells 12, as dark areas. Furthermore, the electrode body 30, the foil bodies 31, 32, and the collectors 33, 34, which are located inside the battery cell 12, are shown by a dashed line, with the foil bodies 31, 32 being shown as hatched areas.

[0067] As in Fig. As shown in Figure 8, the pair of vertical ribs 15, arranged on the rear side of each of the battery cells 12, are positioned relatively far apart in the connection direction such that the ribs 15 point to two points (positions near both endpoints in the connection direction) located on the outer side of the battery cell 12. The vertical ribs 15 are positioned such that they do not overlap with the pair of collectors 33, 34 when viewed substantially in the longitudinal direction of the vehicle. In particular, the pair of vertical ribs 15 are slightly offset from the pair of collectors 33, 34 towards a central side of the battery cell 12, substantially in the connection direction.In the present embodiment, the vertical ribs 15 are located at the central-side displacement positions not only with respect to the collectors 33, 34, but also with respect to the foil bodies 31, 32, which are provided at the two ends of the electrode body 30.

[0068] As described above, the paired vertical ribs 15, which point towards the outer points of the battery cell 12, are spaced relatively far apart from the concave groove 27, which is formed in the center of the front surface 25a of the cell housing 25 essentially in the intermediate connection direction, as shown in Fig. Figure 4 shows that each distance between the concave groove 27 and the vertical ribs 15 in the intermediate connection direction is chosen to be approximately equal. In other words, the concave groove 27 is formed at a position corresponding to the center between the paired vertical ribs 15. Operation and effects

[0069] As described above, the battery device 1 of the first embodiment is configured such that the multiple battery cells 12 inside the housing 11 are arranged in a longitudinal row, with the paired vertical ribs 15 positioned such that they are spaced apart from each other in the intermediate connection direction of the battery cell 12 between the rear surface 25b of the cell housing 25 of each battery cell 12 and the element (intermediate cell plate 13 or rear surface 21b of the housing body 21) that is positioned adjacent to the rear surface 25b. This structure effectively prevents damage to the electrode body 30 when a load is applied to the battery cell 12.

[0070] For example, if an obstacle contacts the battery device 1 from the front during a frontal vehicle collision, a comparatively large impact load acts on the front surface 21a of the housing 11 (enclosure body 21). Since the housing 11 has high strength, the impact load acting from the front is generally absorbed by the housing 11, thus preventing the impact load from being transferred directly to the battery cell 12. However, in a case where the impact load is large, or where the impact load acts only partially due to the small width of the obstacle or similar factors, a situation arises in which part of the load that was not absorbed by the housing 11 acts on the cell casing 25 of the foremost (belonging to the foremost stage) battery cell 12.In a case where the impact load acts on the foremost battery cell 12, a further case occurs in which the impact load acts on the rear battery cell 12 via the battery cell 12 belonging to the foremost stage, which is set back, thereby absorbing the impact load. According to the first embodiment described above, the vertical ribs 15, which are provided on the rear side of each of the battery cells 12, can prevent the cell housing 25 of each of the battery cells 12 from being deformed in such a way as to damage the electrode body 30 inside the cell housing 25, thus protecting the electrode body 30 from damage.

[0071] This means that in the first embodiment described above, because the paired vertical ribs 15, which are spaced apart from each other in the intermediate connection direction, are arranged between the rear surface 25b of the cell housing 25 of each of the battery cells 12 and the adjacent element (inter-cell plate 13 or rear surface 21b of the housing body 21) which is adjacent to the rear surface 25b, a space formed between two vertical ribs 15 can be used as a space that allows bending deformation of the cell housing 25.If, for example, the impact load is introduced from the front into the cell housing 25 of the battery cell 12 belonging to the foremost stage during a frontal vehicle impact, the cell housing 25, which is pushed backward by the impact load, is absorbed by the rear vertical ribs 15, which are positioned on the rear side of the cell housing (paired vertical ribs 15 which are attached to the intermediate cell plate 13 belonging to the foremost stage), such that a bending moment occurs, causing the cell housing 25 to bend backward about the vertical ribs 15, which serve as the center of rotation. This bending moment acts as shown in . Fig. 9 is shown, such that the cell casing 25 is deformed in an arc shape, whereby a central section of the cell casing 25, which is located between the paired vertical ribs 15, is displaced to the rear (in Fig. (Figure 9 shows the thickness of the vertical rib 15 exaggerated for clarity). The space formed between the paired vertical ribs 15 thus acts as a space that allows bending deformation of the central section of the cell housing 25, thereby promoting bending deformation of the cell housing 25. Since the impact energy is sufficiently absorbed by the bending deformation of the cell housing 25, it prevents the cell housing 25 from being deformed to such an extent that it is severely compressed in the thickness direction. This prevents damage to the electrode body 30 inside the cell housing 25 and a short circuit caused by this damage. In a case where, for example, the separator 43 inside the electrode body 30 is broken or damaged, the impact energy is sufficiently absorbed by the cell housing 25.If the separator 43 is damaged, the positive electrode layer 41 and the negative electrode layer 42 make direct contact (short circuit), resulting in a high current flow and potentially causing abnormal heat generation. According to the previously described structure, where the change in the thickness of the cell housing 25 is suitably small, a situation can be avoided in which a compression force sufficient to break the separator 43 acts on the electrode body 30, thus effectively preventing a short circuit.

[0072] Even in a case where an impact load acts on the rear battery cell 12 via the battery cell 12 belonging to the front stage, the possibility of damage to the cell housing 25 is reduced by the action of the vertical ribs 15, which are positioned on the rear of the battery cell 12 similarly to the case described above. This reduces damage to the electrode body 30 and prevents a short circuit caused by such damage. Since the magnitude of the load applied to the rear-positioned battery cell 12 tends to be lower, the risk of damage to the electrode body 30 of the rear-positioned battery cell 12 can be reduced even further.

[0073] This means that, according to the first embodiment, the deformation of the cell housing 25 can be controlled or regulated by the comparatively simple structure in which the vertical ribs 15 are provided between the rear surface 25b of the cell housing 25 and the adjacent element adjacent to this rear surface 25b, so that the thickness of the cell housing 25 is not greatly reduced (squashed), thus preventing damage to the electrode body 30 inside the cell housing 25 and a short circuit caused by this damage.

[0074] Furthermore, since in the first embodiment described above the concave groove 27, which extends in the vertical direction, is formed on the central section of the front surface 25a of the cell housing 25, the concave groove 27 can act as the starting point for the bending deformation of the cell housing 25. The controllability of the deformation of the cell housing 25 is further improved, thus reducing the possibility of crushing the cell housing 25 (significant reduction in thickness), and effectively preventing damage (short circuit) to the electrode body 30 inside the cell housing 25.

[0075] Since, according to the first embodiment, the paired vertical ribs 15 are positioned such that they do not overlap with the paired collectors 33, 34, which connect the electrode body 30 and the terminals 26A, 26B essentially in the intermediate connection direction, a situation in which the collectors 33, 34 and the cell housing 25 contact each other when a load is applied from the outside of the vehicle can be avoided. This means that a problem exists insofar as the rear surface 25b of the cell housing 25 can be partially deformed by absorbing a load from the vertical ribs 15 when the aforementioned load is applied.However, since, according to the first embodiment, the collectors 33, 34 and the vertical ribs 15 do not overlap when viewed in the longitudinal direction of the vehicle, the distance between the rear surface 25b and the collectors 33, 34 is not significantly reduced, even if the reaction force from the vertical ribs 15 causes the rear surface 25b of the cell housing 25 to be partially deformed forward. Contact between the cell housing 25 and the collectors 33, 34, and the resulting short circuit, can thus be prevented. Practical example

[0076] In connection with the present and other inventions, a simulation was carried out which confirmed the effects of the first embodiment described above. In particular, as described in Fig. Figure 10 shows the simulation of the introduction of a specified load into the center of the front surface 25a of the cell housing 25 for each case, i.e., for each housing, by varying a rib spacing Lr, which corresponds to a distance in the intermediate connection direction between the paired vertical ribs 15 (distance between the respective centers of the two ribs 15), and a groove width Lb, which corresponds to the width of the concave groove 27 of the front surface 25a of the cell housing 25. A load acting on the electrode body 30 was specified for each of the cases, i.e., for each housing (hereinafter referred to as "electrode body stress"). In the present simulation, the thickness H, which corresponds to the longitudinal dimension of the vertical rib 15, is a constant value of 2 mm.

[0077] Fig. 11A and Fig. Figure 11B contains graphs illustrating the results of the simulation described above. In particular, Fig. 11A a graph to represent a relationship between an inter-rib width ratio (Lr / Lc) and an electrode body stress, wherein the aforementioned inter-rib width ratio is defined as the ratio (=Lr / Lc) of a cell width Lc, which corresponds to the size given in width (size given in the inter-connection direction) of the cell housing 25 of the battery cell 12, and the rib spacing Lr described above. Fig. Figure 11B is a graph illustrating the relationship between a slot width ratio (Lb / Lc) and the electrode body stress, where the previously described slot width ratio is defined as the ratio (=Lb / Lc) of the cell width Lc and the previously described slot width Lb. In both graphs, the "breakage stress," shown with a dashed line, denotes the electrode body stress at which a separator 43 breaks, which occurred at 0.1 GPa in the present simulation.

[0078] As in Fig. As shown in Figure 11A, there is a tendency for the electrode body stress to decrease as the inter-rib width ratio (Lr / Lc) increases. In particular, when the inter-rib width ratio (Lr / Lc) increases to 0.68 or more, the electrode body stress falls to a level below the fracture stress (0.1). Accordingly, it is preferred to select an inter-rib width ratio (Lr / Lc) of 0.68 or more.

[0079] As in Fig. As shown in Figure 11B, the relationship between the slot width ratio (Lb / Lc) and the electrode body stress is opposite to the previously described relationship between the inter-rib width ratio (Lr / Lc) and the electrode body stress ( Fig. 11A). This means that there is a tendency for the electrode body stress to decrease as the slot width ratio (Lb / Lc) decreases. In particular, when the slot width ratio (Lb / Lc) drops to 0.16 or less, the electrode body stress falls to a level below the fracture stress (0.1). Accordingly, it is preferred if the slot width ratio (Lb / Lc) is selected to be 0.16 or less.

[0080] According to the results described above, it has been found that when protecting the separator 43 from breakage, it is preferable to choose the rib spacing Lr such that the ratio of the rib widths between the ribs (Lr / Lc) is 0.68 or more, and also to choose the groove width Lb such that the groove width ratio (Lb / Lc) is 0.16 or less. (2) Second embodiment

[0081] While the first embodiment described above is designed such that the battery device 1 is arranged in the engine compartment R, which is formed on the front section of the vehicle body 2, and paired vertical ribs 15 are provided on the rear side of each of the battery cells 12 as measures for a load introduced into the battery device 1 from the front in the event of a frontal collision or the like, the battery device can also be arranged on a rear section of the vehicle body 2. In this case, it is desirable to implement measures for a load introduced into the battery device from the rear in the event of a rear-end collision or the like.Below, a second embodiment of the present invention is described as a further example of the battery device in which measures for a load introduced from the rear are implemented.

[0082] Fig. 12 is a plan section view accordingly Fig. 4 to illustrate the structure of a battery device 1A according to the second embodiment. In Fig. The elements in 12 are the same as in the first embodiment and are designated with the same reference numerals, therefore a specific description of them is omitted. As shown in the figure, the battery device 1A comprises several (four) battery cells 112 arranged in a row in the longitudinal direction inside the housing 11. The battery cell 112 comprises a cell housing 125, which is a flat rectangle (plate-shaped body) having a dimension (thickness) in the longitudinal direction of the vehicle that is smaller than a dimension in the width direction of the vehicle, and paired electrodes 126A, 126B, which project substantially upwards from an upper surface 125f of the cell housing 125. In other words, the cell housing 125 is designed such that a front surface 125a and a rear surface 125b have a larger area than the other surfaces of the cell housing 125.The cell housing 125 of the battery cell 112 has a concave groove 127 which extends substantially in the vertical direction along a central section of the rear surface 125b given in the vehicle width direction (in the intermediate connection direction of the battery cell 112). Accordingly, as in . Fig. Figure 12 shows that when provided in a vehicle, the cell housing 125 is arranged such that the front surface 125a faces substantially towards the front of the vehicle, whereas the rear surface 125b faces substantially towards the rear of the vehicle.

[0083] Each of the intermediate cell plates 13 is provided between the adjacent battery cells 112. Pairs of vertical ribs 15, projecting rearward, are provided on the rear surface of the intermediate cell plate 13, which is the surface of the intermediate cell plate 13 facing the rear of the vehicle. Furthermore, additional pairs of vertical ribs 15, projecting rearward, are provided on the front surface 21a of the housing body 21. In other words, two vertical ribs 15 are provided for each of the battery cells 112. The pairs of vertical ribs 15 for each of the battery cells 112 are arranged such that they are spaced apart from each other in the vehicle width direction (in the intermediate connection direction). Furthermore, the pairs of vertical ribs 15 are positioned such that they align with the pairs of collectors 33, 34 (see Fig. 8) overlap substantially in the longitudinal direction of the vehicle when viewed from the side.

[0084] As described above, in the second embodiment, since the paired vertical ribs 15, which are spaced apart from each other in the intermediate connection direction, are provided between each of the battery cells 112 and the adjacent element (intermediate cell plate 13 and front surface 21a of the housing body 21) at the front of the battery cell 112, the cell housing 125 of the battery cell 112 is deformed in an arc-shaped manner when an impact load is introduced into the battery device 1A from the rear during a rear-end collision or the like, for a similar reason as in the first embodiment described above. Furthermore, this deformation is promoted by the concave groove 127, which is formed on the central section of the rear surface 125b of the cell housing 125 (in a central position between the paired vertical ribs 15).This prevents crushing of the cell housing 125, so that the interior of the electrode body 30 (. Fig. 6) can be protected.

[0085] In the second embodiment, the rear surface 125b of the cell housing 125 corresponds to a "first main surface" of the present invention, while the front surface 125a of the cell housing 125 corresponds to a "second main surface" of the present invention. Furthermore, the intermediate cell plate 13, which is provided adjacent to each of the battery cells 112 belonging to the rear three stages with the vertical ribs 15 between them, corresponds to an "adjacent element" of the present invention. Furthermore, the front surface 21a of the housing body 21, which is provided adjacent to the battery cell 112 belonging to the foremost stage with the vertical ribs 15 between them, corresponds to another "adjacent element" of the present invention. Third embodiment

[0086] The battery device can be located close to a side surface of the vehicle body. In this case, it is necessary to implement measures for a load introduced into the battery device from an outer surface of the vehicle body, substantially in the vehicle's width direction, during a side impact or the like. A third embodiment of the present invention, a further example of the battery device, is described below, in which measures are implemented for a load introduced from the outer surface of the vehicle body, substantially in the vehicle's width direction.

[0087] Fig. 13 is a plan section view accordingly Fig. 4 to illustrate the structure of a battery device 1B according to the third embodiment. In Fig. Figure 13 contains the same structural elements as in the first embodiment, designated with the same reference numerals, and a specific description thereof is omitted. As shown in this figure, the battery device 1B comprises several (four) battery cells 212 arranged in a row substantially in the vehicle width direction, and a housing 111 that accommodates the battery cells 212.

[0088] The battery cell 212 comprises a cell housing 225, which is a flat rectangle (plate-shaped body) with a dimension (thickness) in the vehicle width direction that is smaller than a dimension in the vehicle length direction, and paired electrodes 226A, 226B that project substantially upwards from an upper surface 225f of the cell housing 225. In other words, the cell housing 225 is designed such that an outer surface 225a and an inner surface 225b have a larger area than the other surfaces of the cell housing 225. The cell housing 225 of the battery cell 212 may have a concave groove 227 that extends substantially in the vertical direction along a central section of the outer surface 225a given in the vehicle length direction (intermediate connection direction of the battery cell 212).

[0089] The housing 111 comprises a box-shaped housing body 121. The housing body 121 comprises an outer surface 121a facing the outer surface 225a of the battery cell 212, which is positioned at the outermost side, and an inner surface 121b facing the inner surface 225b of the battery cell 212, which is positioned at the innermost side. Accordingly, when installed in a vehicle, the housing 111 of the lithium-ion battery device is arranged such that the outer surface 121a faces substantially towards the outside of the vehicle, whereas the inner surface 121b faces substantially towards the inside of the vehicle. In particular, when installed in a vehicle, the cell housing 225 of the battery cell 212 is arranged such that the outer surface 225a of the cell housing 225 faces substantially towards the outside of the vehicle in a vehicle width direction.

[0090] Each of the inter-cell plates 113 is provided between adjacent battery cells 212. Paired vertical ribs 15, projecting outwards, are provided on an outer surface of the inter-cell plate 13. In particular, each of the vertical ribs 15 (gap-forming sections) comprises an area having a surface area smaller than the surface area of ​​the inner surface 225b. Additionally, each of the vertical ribs 15 has a thickness in the vehicle width direction, that is, each of the vertical ribs 15 extends substantially in the vehicle width direction. Furthermore, the paired vertical ribs 15, projecting outwards, are also provided on the inner surface 121b of the housing body 121. In other words, the two vertical ribs 15 are provided for each of the battery cells 212.The pair of vertical ribs 15 for each of the battery cells 212 are spaced apart from each other essentially in the longitudinal direction of the vehicle (in the intermediate connection direction). Furthermore, the pair of vertical ribs 15 are positioned such that the vertical ribs 15 are connected to the pair of collectors 33, 34 (. Fig. 8) do not overlap when viewed primarily in the direction of the vehicle's width.

[0091] As described above, in the third embodiment, since the paired vertical ribs 15, which are spaced apart from each other in the intermediate connection direction, are provided between each of the battery cells 212 and the adjacent element (inter-cell plate 13 and inner surface 121b of the housing body 121), the cell housing 225 of the battery cell 212 is deformed in an arc-shaped manner when an impact load is introduced into the battery device 1B from the outside during a side impact of a vehicle or the like, which has the same cause as in the first embodiment described above. Furthermore, this deformation is promoted by the concave groove 227, which is formed on the central section of the outer surface 225a of the cell housing 225 (at a central position between the paired vertical ribs 15).This prevents the cell housing 225 from being crushed, so that the interior of the electrode body 30 (. Fig. 6) can be protected.

[0092] In the third embodiment, the outer surface 225a of the cell housing 225 corresponds to a "first main surface" of the present invention, while the inner surface 225b of the cell housing 225 corresponds to a "second main surface" of the present invention. Furthermore, the intermediate cell plate 13, which is provided adjacent to each of the battery cells 212 (belonging to the outer three stages), with the exception of the battery cell 212 positioned on the innermost side, and with the vertical ribs 15 between them, corresponds to an "adjacent element" of the present invention. The inner surface 121b of the housing body 121, which is provided adjacent to the battery cell 212 positioned on the innermost side, and with the vertical ribs 15 between them, corresponds to another "adjacent element" of the present invention. (4) Fourth embodiment

[0093] While the first embodiment described above is configured such that the multiple battery cells 12 are arranged in a row in the longitudinal direction of the vehicle, and the vertical ribs 15, which have the same shape, are positioned directly behind each of the battery cells 12, the shape (thickness) of the vertical ribs 15 can be varied according to the battery cells 12. In other words, the vertical ribs 15 can be configured to have a variable thickness. An example of this is described below as the fourth embodiment.

[0094] Fig. 14 is a plan section view accordingly Fig. 4 to illustrate the structure of a battery device 1C according to the fourth embodiment. In Fig. 14 are the same structural elements as in the first embodiment, designated with the same reference numerals, without a specific description thereof. As shown in this figure, the battery device 1C comprises the multiple battery cells 12, which are arranged in a row in the longitudinal direction of the vehicle inside the housing 111, the multiple intermediate cell plates 13, which are provided between the adjacent battery cells 12, and multiple vertical ribs 115A, 115B, 115C, which project forward from the intermediate cell plates 13.The multiple vertical ribs 115A, 115B, 115C comprise paired vertical ribs 115A projecting forward from the intermediate cell plate 13, which is positioned directly behind the battery cell 12 belonging to the foremost stage; paired vertical ribs 115B projecting forward from the intermediate cell plate 13, which is positioned directly behind the battery cell 12 belonging to the second stage; and paired vertical ribs 115C projecting forward from the intermediate cell plate 13, which is positioned directly behind the battery cell 12 belonging to the third stage. No element corresponding to a vertical rib is provided behind the battery cell 12 belonging to the rearmost stage (on the rear surface 21b of the housing body 21).

[0095] The thickness (longitudinally specified dimension) of the vertical ribs 115A, 115B, 115C is chosen such that the frontmost vertical rib has a greater thickness. This means that the thickness of the vertical rib 115B belonging to the second stage is greater than that of the vertical rib 115C belonging to the third stage, and the thickness of the vertical rib 115A belonging to the foremost stage is greater than that of the vertical rib 115B belonging to the second stage. Fig. In figure 14, the thickness of the vertical rib 115A belonging to the foremost stage is exaggerated to make it easier to understand the different thicknesses.

[0096] According to the fourth embodiment described above, it is possible to prevent the battery device 1C from being built large, and the previously described damage-preventing effect of the electrode body 30 remains ( Fig. 6) obtained. This means that when a load is introduced into the battery device 1C from the front of the vehicle during a frontal collision or the like, the battery cell 12 belonging to the foremost stage tends to deform the most when absorbing the load, with the extent of deformation experienced by the other battery cells 12, which are positioned at the rear of the vehicle, gradually decreasing. This, in turn, means that the impact energy is absorbed sufficiently (strongly) by the foremost battery cell 12 that the rear battery cells 12 are less affected by the impact load, so that the extent of deformation of these battery cells 12 is reduced.According to the fourth embodiment described above, since the thickness of the vertical ribs is chosen to be smaller in accordance with the rear battery cells 12, it is effectively prevented that the battery device 1C is built large, and the previously described damage-preventing effect of the electrode body 30 is retained.

[0097] In the fourth embodiment, the battery cell 12 belonging to the second stage or the third stage corresponds to an “additional battery cell” of the present invention, the intermediate cell plate 13 (belonging to the second stage or the third stage) corresponding to this battery cell 12 corresponds to an “additional adjacent element” of the present invention, and the vertical ribs 115B or 115C (belonging to the second stage or the third stage) corresponding to this intermediate cell plate 13 correspond to an “additional gap-forming section” of the present invention.In a combination of the battery cell 2 belonging to the front stage and the battery cell 12 belonging to the second stage, the battery cell 12 belonging to the front stage, the intermediate cell plate 13 belonging to the front stage and the vertical rib 115A belonging to the front stage correspond, for example, to the “battery cell”, the “adjacent element” or the “gap-forming section”, while the battery cell 12 belonging to the second stage, the intermediate cell plate 13 belonging to the second stage and the vertical rib 115B belonging to the second stage correspond to the “additional battery cell”, the “additional adjacent element” or the “additional gap-forming section”.In a combination of the battery cell 12 belonging to the second stage and the battery cell 12 belonging to the third stage, the battery cell 12 belonging to the second stage, the intermediate cell plate 13 belonging to the second stage and the vertical rib 115A belonging to the second stage correspond to the “battery cell”, the “adjacent element” or the “gap-forming section”; and the battery cell 12 belonging to the third stage, the intermediate cell plate 13 belonging to the third stage and the vertical rib 115C belonging to the third stage correspond to the “additional battery cell”, the “additional adjacent element” or the “additional gap-forming section”.

[0098] While the fourth embodiment described above provides a total of three pairs of vertical ribs 115A, 115B, 115C, corresponding to the front battery cells 12 belonging to the three stages, it is possible to increase or decrease the number of pairs of vertical ribs, as long as at least two pairs of vertical ribs are provided. For example, the vertical ribs can also be provided behind the battery cell 12 belonging to the rearmost stage; alternatively, the vertical ribs can also be provided only behind the battery cell 12 belonging to the rearmost stage and behind the battery cell 12 belonging to the second stage (that is, the vertical ribs 115C belonging to the third stage can be omitted).

[0099] Although the battery device 1C of the aforementioned fourth embodiment is designed based on the battery device 1 of the aforementioned first embodiment and incorporates measures for a load introduced from the front of the vehicle, the structure in which the thickness of the vertical rib can be varied according to the position of the battery cell, as in the fourth embodiment, is also applicable to the battery device 1A of the second embodiment, in which measures are implemented for a load introduced from the rear of the vehicle ( Fig. 12), or applicable to the battery device 1B of the third embodiment, in which measures are implemented for a load introduced from the outside of the vehicle ( Fig. 13). (5) Other embodiments

[0100] Although in the first embodiment the concave groove 27 is formed only on the front surface 25a of the cell housing 25 of the battery cell 12, the concave groove can also be formed on both the front surface 25a and the rear surface 25b of the cell housing 25.

[0101] Although in the first embodiment the two vertical ribs 15 are provided on each of the battery cells 12 and the paired vertical ribs 15 are offset from the paired collectors 33, 34 towards the central side of the battery cell 12 in the intermediate connection direction (inwards), the two vertical ribs 15 can also be provided such that they are offset from the paired collectors 33, 34, as in Fig. 15 is shown, for example, offset outwards, as long as the vertical ribs 15 are located in positions that are spaced apart from the center of the battery cell 12 given in the intermediate connection direction in such a way that the ribs 15 do not overlap with the collectors 33, 34.

[0102] Although in the first embodiment the two vertical ribs 15 (gap-forming sections), which have a rod shape and extend in the vertical direction, are provided on each of the battery cells 12, the shape or arrangement position of the gap-forming sections can be suitably changed, as long as the two gap-forming sections of the present invention are provided on the battery cell in such a way that the gap-forming sections are spaced apart from each other in the intermediate connection direction.

[0103] As in Fig. As shown in Figure 16A, for example, four L-shaped elements 215, spaced apart from each other both vertically and in the connection direction, can be provided as gap-forming sections. Furthermore, as shown in Fig. As shown in Figure 16B, two circular elements 315, spaced apart from each other in the vertical direction and in the intermediate connection direction, are provided as gap-forming sections.

[0104] Although various modifications to the first embodiment have been described, these modifications are also applicable to the other embodiments (the second to fourth embodiments).

Claims

[1] Lithium-ion battery device for a vehicle, comprising: an enclosure (11); a battery cell (12) which is housed inside the enclosure (11); and an adjacent element that is adjacent to the battery cell (12) and is provided on a rear side thereof in a longitudinal direction of the vehicle, wherein the battery cell (12) comprises: a cell housing (25), an electrode body (30) which is housed inside the cell housing (25), and a pair of terminals (26A, 26B) which are provided on a surface (25f) of the cell housing (25), wherein the cell housing (25) includes a first main surface and a second main surface, each having a larger area than the surface (25f) on which the pair of terminals (26A, 26B) are provided, wherein the first main surface and the second main surface face each other in the longitudinal direction of the vehicle, wherein the second main surface is arranged on the rear side of the first main surface in the longitudinal direction of the vehicle, at least two gap-forming sections (15), each having a smaller area than the area of ​​the second main surface and having a specified thickness (H) in the longitudinal direction of the vehicle, are arranged between the second main surface and the adjacent element, wherein the at least two gap-forming sections (15) are spaced apart from each other in an intermediate connection direction of the battery cell (12), and wherein the battery cell (12) further comprises a pair of collectors (33, 34), which connect the electrode body (30) and the pair of terminals (26A, 26B) inside the cell housing (25), and the two gap-forming sections (15) are positioned such that the two gap-forming sections (15) do not overlap with the pair of collectors (33, 34) when viewed in a longitudinal direction of the vehicle, and wherein the first main surface of the cell housing (25) has a concave groove (27) positioned between the two gap-forming sections (15) and extending in a direction perpendicular to the intermediate connection direction of the battery cell (12). [2] Lithium-ion battery device for a vehicle according to claim 1, further comprising: an additional battery cell (12) provided on the rear side of the battery cell (12) in the longitudinal direction of the vehicle, and an additional adjacent element provided adjacent to the additional battery cell (12) and on the rear side thereof in the longitudinal direction of the vehicle, wherein an additional gap-forming section (15) having a smaller thickness (H) in the longitudinal direction of the vehicle than the thickness (H) of the two gap-forming sections (15) in the longitudinal direction of the vehicle is provided between the additional battery cell (12) and the additional adjacent element. [3] Lithium-ion battery device for a vehicle, comprising: an enclosure (11); a battery cell (112) which is housed inside the enclosure (11); and an adjacent element that is adjacent to the battery cell (112) and is provided on a front side thereof in a longitudinal direction of the vehicle, wherein the battery cell (112) comprises: a cell housing (125), an electrode body (30) which is housed inside the cell housing (125), and a pair of terminals (126A, 126B) which are provided on a surface (125f) of the cell housing (125), wherein the cell housing (125) includes a first main surface and a second main surface, each having a larger area than the surface (125f) on which the pair of terminals (126A, 126B) is provided, and wherein the first main surface and the second main surface face each other in the longitudinal direction of the vehicle, wherein the second main surface is arranged on the front of the first main surface in the longitudinal direction of the vehicle, at least two gap-forming sections (15), each having a smaller area than the area of ​​the second main surface and having a specified thickness (H) in the longitudinal direction of the vehicle, are arranged between the second main surface and the adjacent element, wherein the at least two gap-forming sections (15) are spaced apart from each other in an intermediate connection direction of the battery cell (12), and wherein the battery cell (112) further comprises a pair of collectors (33, 34) connecting the electrode body (30) and the pair of terminals (126A, 126B) inside the cell housing (125), and the two gap-forming sections (15) are positioned such that the two gap-forming sections (15) do not overlap with the pair of collectors (33, 34) when viewed in the longitudinal direction of the vehicle, and wherein the first main surface of the cell housing (125) has a concave groove (127) which is positioned between the two gap-forming sections (15) and extends in a direction perpendicular to the intermediate connection direction of the battery cell (112). [4] Lithium-ion battery device for a vehicle according to claim 3, further comprising: an additional battery cell (112) provided on the front side of the battery cell (112) in the longitudinal direction of the vehicle, and an additional adjacent element provided adjacent to the additional battery cell (112a) and on the rear side thereof in the longitudinal direction of the vehicle, wherein an additional gap-forming section (15) having a smaller thickness (H) in the longitudinal direction of the vehicle than the thickness (H) of the two gap-forming sections (15) is provided between the additional battery cell (112) and the additional adjacent element. [5] Lithium-ion battery device for a vehicle, comprising: an enclosure (111); a battery cell (212) which is housed inside the enclosure (111); and an adjacent element that is adjacent to the battery cell (212) and is provided on an inside side of it in a vehicle width direction, wherein the battery cell (212) comprises: a cell housing (225), an electrode body (30) which is housed inside the cell housing (225), and a pair of terminals (226a, 226B) which are provided on a surface (225f) of the cell housing (225), wherein the cell housing (225) includes a first main surface and a second main surface, each having a larger area than the surface (225f) on which the pair of terminals (226A, 226B) are provided and pointing towards each other in the vehicle width direction, wherein the second main surface is arranged on the inside of the first main surface in the vehicle width direction, at least two gap-forming sections (15), each having a smaller area than the area of ​​the second main surface and having a specified thickness (H) in the vehicle width direction, are arranged between the second main surface and the adjacent element, wherein the at least two gap-forming sections (15) are arranged spaced apart from each other in an intermediate connection direction of the battery cell (212), and wherein the battery cell (212) further comprises: a pair of collectors (33, 34) connecting the electrode body (30) and the pair of terminals (226A, 226B) inside the cell housing (225), and the two gap-forming sections (15) being positioned such that the two gap-forming sections (15) do not overlap with the pair of collectors (33, 34) when viewed in the vehicle width direction, and wherein the first main surface of the cell housing (225) has a concave groove (227) which is positioned between the two gap-forming sections (15) and extends in a direction perpendicular to the intermediate connection direction of the battery cell (212). [6] Lithium-ion battery device for a vehicle according to claim 5, further comprising: an additional battery cell (212) provided on the outside of the battery cell (212) in the vehicle width direction, and an additional adjacent element provided adjacent to the additional battery cell (212) and on the inside thereof in the vehicle width direction, wherein an additional gap-forming section (15) having a smaller thickness (H) in the vehicle width direction than the thickness (H) of the two gap-forming sections in the vehicle width direction is provided between the additional battery cell (212) and the additional adjacent element. [7] Vehicle comprising the lithium-ion battery device according to one of claims 1 to 2, wherein the lithium-ion battery device is arranged such that the first main surface of the cell housing (15) faces the front of the vehicle. [8] Vehicle comprising the lithium-ion battery device according to one of claims 3 to 4, wherein the lithium-ion battery device is arranged such that the first main surface of the cell housing (125) faces the rear of the vehicle. [9] Vehicle comprising the lithium-ion battery device according to one of claims 5 to 6, wherein the lithium-ion battery device is arranged such that the first main surface of the cell housing (225) faces the outside of the vehicle.

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