JP2011165483A - Lithium ion secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery improved in cooling performance without installing a heat sink inside a wound body and having high reliability. <P>SOLUTION: The lithium ion secondary battery has a positive electrode plate, a negative electrode plate, and a separator, and further there are formed a first battery case which houses a power generation element in which the positive electrode plate and the negative electrode plate are laminated through the separator, a second battery case which surrounds the surroundings outside of the first battery case throughout the whole surroundings and houses the power generation element, and a space part formed between the first battery case and the second battery case and surrounding the entire surroundings outside of the first battery case. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lithium ion secondary battery, and more particularly to a lithium ion secondary battery incorporating a battery structure for releasing heat generated in a large capacity lithium ion secondary battery.

  In recent years, lithium ion secondary batteries have been developed as power sources for hybrid vehicles, electric vehicles, and hybrid railway vehicles, and as industrial storage batteries such as power storage.

  As the use of lithium ion secondary batteries expands in this way, there is an increasing demand for higher charge / discharge capacity, and the increase in size of lithium ion secondary batteries has become indispensable.

  A lithium ion secondary battery includes a wound body formed by winding a positive electrode and a negative electrode in a spiral shape with a separator interposed therebetween, an electrolytic solution, and a battery case that houses these.

  When the size of such a lithium ion secondary battery is increased, the amount of heat generated during charging / discharging increases and heat dissipation deteriorates, so the temperature rise of the battery during charging / discharging increases, and the temperature distribution of the winding body also increases. Since it becomes large, it is said that problems of local degradation and performance degradation occur.

  For this reason, for example, as described in Patent Document 1, a lithium ion secondary battery that cools the wound body is considered.

  The lithium ion secondary battery disclosed in Patent Document 1 is a wound body in which a heat dissipation plate is disposed radially apart from the inside of the winding body, and a positive electrode, a negative electrode, and a separator are stacked between the heat dissipation plates. Part is sandwiched.

  The heat sink extends beyond the positive electrode, negative electrode, and separator, the end face of the heat sink is exposed to the outside, and the heat generated in the lithium ion secondary battery is released to the outside of the battery case through the end face in the extending direction of the heat sink. Is done.

  Furthermore, a through-hole communicating with the outside is formed in the heat radiating plate to increase the area where the heat radiating plate can directly contact with the outside air.

JP 2008-135312 A

However, in the lithium ion secondary battery disclosed in Patent Document 1, since the heat sink is formed inside the wound body, the weight of the lithium ion secondary battery increases, and the energy density per weight, per weight The capacity density of is reduced.
Accordingly, an object of the present invention is to provide a highly reliable battery with improved cooling performance without providing a heat sink inside the wound body.

  A lithium ion secondary battery (hereinafter referred to as “battery”) according to an embodiment of the present invention includes a positive electrode plate, a negative electrode plate, and a separator, and the positive electrode plate and the negative electrode plate are interposed via the separator. A first battery case that houses the power generation element bodies stacked in layers, a second battery case that surrounds the entire outer periphery of the first battery case, and houses the power generation element bodies, and the first battery case. A space portion is formed between the battery case and the second battery case and surrounds the entire periphery of the outside of the first battery case.

  In the power generating element body in which the positive electrode plate and the negative electrode plate are laminated via the separator, the thermal conductivity in the laminating direction is extremely poor, so that a large temperature distribution occurs in the laminating direction.

  By separating the battery case into two in the stacking direction of the power generation element bodies, the heat conduction distance in the stacking direction of the power generation element bodies housed in the respective battery cases can be shortened.

  Then, by ventilating the space, forced convection heat transfer occurs on the surface of the battery case that is in direct thermal contact with the power generation element body, and the inside of both battery cases of the first battery case and the second battery case. This effectively removes the heat generated by the power generation element body.

  In addition, since the heat conduction distance is shortened, the temperature gradient in the stacking direction of the power generation element bodies inside both battery cases is reduced, and the temperature distribution of the power generation element bodies is uniformed.

  In addition, a lithium ion secondary battery according to an embodiment of the present invention includes a third battery case that surrounds the entire outer periphery of the second battery case and houses the power generation element body, It is preferable that a space portion is formed between the second battery case and the third battery case so as to surround the entire periphery of the outside of the second battery case.

  Further, the fourth battery case, the fifth battery case, etc. are connected to the power generation element body in the same arrangement relationship as the second battery case and the third battery case over the entire periphery outside the third battery case. It is also possible to arrange them sequentially toward the outside in the stacking direction.

  As a result, even when the capacity of the battery increases and the size of the battery increases, the number of battery cases is reduced, and the power generation element inside each battery case is used while maximizing effective use of the battery storage space. The heat conduction distance in the stacking direction of the bodies can be within an allowable range.

  As a result, even if the capacity of the battery increases, the temperature distribution of the power generation element body can be made uniform.

  There are other ways to divide the battery.

  For example, it is assumed that a predetermined heat conduction distance Δr is set from the viewpoint of improving the temperature distribution.

  When considering the configuration of cylindrical batteries (cells) having the same capacity, the installation area is almost the same when comparing the battery of this embodiment with a plurality of cylindrical cells having a radius Δr. However, the number of battery cases of the battery of this embodiment is reduced to 1/3 or less compared to a plurality of cylindrical cells having a radius Δr.

  In the lithium ion secondary battery according to an embodiment of the present invention, it is preferable that the space portion is ventilated with outside air.

  In the lithium ion secondary battery according to an embodiment of the present invention, it is preferable that the first battery case has a cylindrical shape or a hollow cylindrical shape, and the second battery case has a hollow cylindrical shape.

  Thereby, the shape of the power generation element body can be formed by winding the positive electrode, the negative electrode, and the separator in a band shape, and can correspond to a cylindrical power generation element body.

  Moreover, in the lithium ion secondary battery according to an embodiment of the present invention, it is preferable that the first battery case has a rectangular column shape or a hollow rectangular column shape, and the second battery case has a hollow square column shape. .

  Thereby, the shape of the power generation element body can correspond to a rectangular power generation element body formed by winding the positive electrode, the negative electrode, and the separator in a band shape.

  In addition, a lithium ion secondary battery according to an embodiment of the present invention is formed at both ends of the first battery case and the positive terminal and the negative terminal formed at both ends of the first battery case. A positive terminal portion formed on both ends of the first battery case and a positive terminal portion formed on both ends of the second battery case, and / or And it is preferable to fix the negative electrode terminal part formed in the both ends of the said 1st battery case, and the negative electrode terminal part formed in the both ends of the said 2nd battery case using a plate-shaped support material.

  In addition, a lithium ion secondary battery according to an embodiment of the present invention is formed at both ends of the first battery case and the positive terminal and the negative terminal formed at both ends of the first battery case. A positive terminal formed on both ends of the first battery case, and a positive terminal formed on both ends of the third battery case, and a positive terminal formed on both ends of the first battery case. Terminal portions, positive terminal portions formed at both ends of the second battery case and positive terminal portions formed at both ends of the third battery case, and / or both ends of the first battery case A plate-shaped support material is used to form a negative electrode terminal portion formed at each end of the second battery case, a negative electrode terminal portion formed at both ends of the second battery case, and a negative electrode terminal portion formed at both ends of the third battery case. It is preferable to fix.

  In the lithium ion secondary battery according to an embodiment of the present invention, the plate-like support material is preferably a current collecting terminal member.

  Thereby, each separated battery case can be fixed, and the number of parts can be suppressed by having the function of collecting current from the terminals of each battery case with the plate-like support member.

  In the lithium ion secondary battery according to an embodiment of the present invention, a member that can be ventilated and extended and contracted is inserted into the space portion, and the member forms an inner periphery of the space portion. It is preferable that the battery case is bonded or fixed to the outer wall surface of the battery case and the inner wall surface of the second battery case that forms the outer periphery of the space portion.

  In the lithium ion secondary battery according to an embodiment of the present invention, a member that can be ventilated and extended and contracted is inserted into the space portion, and the member forms an inner periphery of the space portion. An outer wall surface of the battery case; an inner wall surface of the second battery case that forms an outer periphery of the space portion; an outer wall surface of the second battery case that forms an inner periphery of the space portion; It is preferable that the third battery case forming the outer periphery of the space is bonded or fixed to the inner wall surface of the third battery case.

  In the space portion, a member that can extend and contract so as to allow ventilation is disposed.

  In addition, as the member that can be expanded and contracted, for example, an elastic body such as a spring, a foam formed from a metal or a resin, a porous body, a mesh-shaped member, or the like is used.

  The plate-like support material that also functions as a current collector terminal is applied with force by heat deformation or mechanical vibration of the battery case due to heat cycle due to long-time operation, but by using a member that can extend and contract, The burden on the material can be reduced, and durability can be improved.

  Thus, the present invention can improve the cooling performance and provide a highly reliable battery without providing a heat sink inside the wound body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an external appearance of a cylindrical battery according to a first embodiment of the present invention. It is a top plan view of the appearance of a cylindrical battery, showing the first embodiment of the present invention. FIG. 2 shows a first embodiment of the present invention and is a cross-sectional view taken along AA in FIG. 1. It is a perspective view of the battery case used for the battery which shows the 1st Example of this invention. It is a graph which shows the result of having analyzed temperature distribution about the improvement effect of temperature distribution. It is a perspective view which shows the 2nd Example of this invention and shows the arrangement | sequence between battery cases. It is a front view of the cylindrical battery in which the electrode terminals are connected in the third embodiment of the present invention. FIG. 10 is a top plan view of a cylindrical battery in which a support material is inserted between battery cases according to a fourth embodiment of the present invention. FIG. 10 is a top plan view of a cylindrical battery in which a support material is partially inserted between battery cases, showing a modification of the fourth embodiment of the present invention. FIG. 10 is a top plan view showing the outer appearance of a prismatic battery according to a fifth embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  The structure of the lithium ion secondary battery according to the first embodiment of the present invention will be described with reference to FIGS.

  1 is a perspective view of the appearance of a cylindrical battery, FIG. 2 is a top plan view of the appearance of the cylindrical battery, FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1, and FIG.

  The battery shown in Example 1 has a positive electrode plate, a negative electrode plate, and a separator.

  A first battery case 1 that houses a power generation element body in which a positive electrode plate and a negative electrode plate are stacked via a separator, and surrounds the entire periphery outside the first battery case 1, A second battery case 2 to be housed, and a space 3 between the first battery case 1 and the second battery case 2 and surrounding the entire periphery outside the first battery case 1 are provided. Is formed.

  That is, as shown in FIG. 1, a cylindrical first battery case 1 is arranged at the center, and a hollow cylindrical (annular) second battery case 2 is arranged so as to surround the outer periphery thereof. Yes. As shown in FIG. 2, an annular space 3 is formed along the axial direction between the first battery case 1 and the second battery case 2.

  In the first battery case 1, a belt-like positive electrode, a negative electrode, and a separator are laminated, and as shown in FIG. 3, a power generation element body wound around a winding shaft 4 with the vertical direction as an axial direction, The rotating body 5 is accommodated in close contact with the inner wall of the first battery case 1.

  In addition, as a material of the winding axis | shaft 4, resin is preferable from an insulating viewpoint.

  As shown in FIG. 4, the second battery case 2 has an annular shape and is a battery case in which at least the upper part 6 is opened.

  Here, the power generation element body similar to the first battery case 1 wound around the winding shaft portion 7 having a hollow structure, that is, the winding body 8 together with the winding shaft portion 7 is a second battery. It is inserted into the annular space 9 of the case 2 from above, and is housed in close contact with the inner and outer inner walls 100 and 101 of the second battery case 2.

  Here, the innermost side of the wound body 8 in contact with the wound shaft portion 7 is preferably a separator. After the wound body 8 is inserted, the battery upper cover 50 is attached, and the second battery case 2 is sealed.

  The outer wall surface of the winding shaft portion 7 is in contact with the inner wall 101 on the inner peripheral side of the second battery case 2. A separator, which is an insulating material, is wound around the outermost peripheral portion of the wound body 8 that is in contact with the inner wall 100 on the outer peripheral side of the second battery case 2.

  In addition, although the shape of the battery case is different between the first and second, the wound body is an annular shape.

  A current collector 10 on the positive electrode side shown in FIG. 3 (corresponding to the first battery case 1) is disposed on the upper part of the wound body 5 and the wound body 8 inside the first battery case 1 and the second battery case 2. ) And a current collector 11 (corresponding to the second battery case 2), respectively, and a negative current collector 12 (corresponding to the first battery case 1) is provided below the wound body 5 and the wound body 8. ) And a current collector 13 (corresponding to the second battery case 2).

  The positive current collector 10 is connected to the positive terminal 14a protruding from the end face of the battery top cover 50, and the positive current collector 11 is connected to the positive terminal 14b protruding from the upper end face of the battery case. 14a and the positive electrode terminal 14b are electrically connected.

  The positive electrode terminal 14a and the positive electrode terminal 14b are insulated from the first battery case 1 and the second battery case 2 by the sealing body 15 on the upper end surface thereof.

  Further, regarding the positive terminal 14a and the positive terminal 14b provided on the upper end surfaces of the first battery case 1 and the second battery case 2, the positive terminal 14a of the first battery case 1 has a cylindrical shape, The positive electrode terminal 14b of the battery case 2 has an annular shape.

  On the other hand, the current collector 12 and the current collector 13 on the negative electrode side below the wound body 5 and the wound body 8 are both inserted into the first battery case 1 and the second battery case 2 when the wound body is inserted. Electrical connection is made to the lower end surfaces 150 of the first battery case 1 and the second battery case 2.

  The positive terminal 14a and the positive terminal 14b corresponding to the first battery case 1 and the second battery case 2 are connected by a positive terminal connecting plate 16a and a positive terminal connecting plate 16b.

  The negative electrode side does not have a terminal protruding from the end surface of the battery case as in the positive electrode side, but the first battery case 1 and the second battery case 2 each have a negative electrode at the lower end surface 150 of the battery case. Electrical connection is made at the inter-terminal connection plate 17.

  The positive terminal connecting plate 16a, the positive terminal connecting plate 16b, and the negative terminal connecting plate 17 connect the battery cases in a physical sense in addition to the electrical connection between the battery cases, It has a role as a support material of each battery case, and thereby each battery case is fixed.

  The connection between the positive terminal and the negative terminal, and the connection between the positive terminal connecting plate and the negative terminal connecting plate are securely fixed by welding or screwing.

  The size and number of the positive electrode terminal connecting plates are appropriately set based on the maximum current value during operation, and at the same time, the strength is considered from the viewpoint of support and fixation.

  Next, the space 3 formed between the first battery case 1 and the second battery case 2 shown in FIG. 3 is ventilated with the outside air of the battery.

  That is, a gas such as air, a cooling medium, or the like can flow through the space 3.

  Further, the outer space portion 18 of the second battery case 2 is also vented to the outside air, so that a gas such as air, a cooling medium, or the like can flow.

  That is, the heat generated in the wound body 5 and the wound body 8 formed inside the first battery case 1 and the second battery case 2 flows from the negative electrode side 20 to the space 3 and the outside. It is taken away by the cooling medium 19 including air flowing through the space 18 and is discharged out of the battery system from between the upper end surface 21 of each battery case and the positive terminal connecting plate 16a.

  What is important in cooling the battery is to keep the temperature of the battery winding body in a predetermined temperature range. Therefore, the maximum temperature inside the power generation element body is controlled by adjusting the flow rate of the cooling medium.

  The region where the temperature is highest is the farthest from the cooling medium.

  FIG. 5 is a graph showing the results of analyzing the temperature distribution with respect to the effect of improving the temperature distribution. In this example, regarding the temperature distribution of the annular winding body, the radial thickness Δr and the winding It is the result of analyzing the relationship between the ratio Δr / R with the outer peripheral radius R of the rotating body and the temperature distribution in the radial direction of the wound body at this time.

  First, it can be seen from FIG. 5 that when Δr, which is the difference between the maximum temperature and the minimum temperature at 5 m, 10 mm, and 15 mm, is compared, ΔT decreases as Δr decreases.

  In the present embodiment, the radial thickness Δr is reduced by dividing the cylindrical battery into two parts, the inner side and the outer side. Further, even when Δr is the same, ΔT becomes smaller as Δr / R is smaller.

  That is, it is preferable that the ring-shaped battery as seen in the second battery case has a larger diameter and a smaller radial thickness Δr.

  If ΔT to be allowed is determined from the viewpoint of battery life and deterioration control, an analysis as shown in FIG. 5 is performed to determine the outer radius R and the radial thickness according to the battery capacity and installation space. Δr and length L can be determined.

  From the viewpoint of improving the cooling efficiency, the wound body 8 housed in the second battery case 2 shown in FIG. 4 is a material having good thermal conductivity, such as copper, as the material of the hollow wound shaft portion 7. By using aluminum or aluminum, the thermal resistance between the winding body and the battery case can be reduced, and as a result, heat transfer between the winding body and the cooling medium is improved.

  According to the present embodiment, the heat conduction distance in the stacking direction of the power generation element body is shortened, and the temperature distribution in the winding portion is effectively uniformed by ventilating the space provided between the battery cases. Therefore, the internal resistance distribution depending on the temperature is reduced, and the current density distribution during charging and discharging and the SOC (charged state) variation width depending on the current density are also reduced.

  That is, a uniform electrochemical reaction can be performed over the entire battery, leading to suppression of deterioration and improvement of life.

  In addition, in a cylindrical cell with a large diameter, the temperature difference in the radial direction becomes large, so there has been an aspect ratio limitation for single cells so far, but the diameter could not be increased. In particular, since there is no restriction from the temperature aspect, a more flexible layout design is possible.

  The second embodiment shows a countermeasure when the capacity is insufficient in two stages as in the first embodiment, and is an embodiment showing a three-stage division.

  FIG. 6 is a perspective view showing an arrangement between battery cases according to the second embodiment.

  As shown in FIG. 6, a cylindrical first battery case 30 is arranged at the center, an annular second battery case 31 is arranged on the outer side, and an annular third battery case 33 is arranged on the outer side. Has been.

  If the capacity increases in the two stages as in the first embodiment, Δr of the second battery must be increased in order to obtain the required capacity (if the length L is increased, it is possible to increase Δr without increasing it). Is possible, but not when length is limited).

  In this embodiment, by increasing the number of divisions, it is possible to cover the capacity while maintaining Δr within the limit.

  Incidentally, in the three battery cases, Δr of the second and third battery cases 31 and 32 is approximately the same, but the third battery case 32 having a larger outer diameter makes Δr larger than that of the second battery case 31. May be.

  The cylindrical first battery case 30 was also mentioned in Example 1, but has a winding shaft in the center, so that the winding body is also an annular shape. 2, Δr / R increases at the same Δr as the third battery case.

  Therefore, in order to keep the same temperature difference ΔT as the second and third, it is desirable that Δr of the first battery case 30 is smaller than that of the second and third battery cases (see FIG. 5).

  In order to use the space as effectively as possible and increase the energy density per volume of the battery, the width of the space portions 33 and 34 between the battery cases may be reduced.

  However, if the width of the space portions 33 and 34 is reduced, the pressure loss when the cooling fluid flows is increased. Therefore, in order to obtain a necessary flow rate, for example, attention should be paid to the specifications of the blower for flowing the medium. is necessary.

  FIG. 7 shows a third embodiment and is a front view of a cylindrical battery in which electrode terminals are connected.

  FIG. 7 shows a connection method of electrode terminals between battery cases in the battery of Example 2, and the orientation of the positive and negative electrodes of the wound body housed in the battery case between adjacent battery cases. Is configured to be the opposite.

  That is, with respect to the first battery case 30, a positive electrode terminal 14a is provided at the upper end surface and a negative electrode terminal 40c is provided at the lower end surface, and with respect to the adjacent second battery case 31, an annular negative electrode terminal 40b is provided at the upper end surface. An annular positive electrode terminal 14b is provided on the lower end surface.

  Regarding the outermost third battery case 32, an annular positive electrode terminal 14c is provided on the upper end surface, and an annular negative electrode terminal 40a is provided on the lower end surface.

  The negative terminal 40c and the positive terminal 14b are connected by an inter-terminal connection plate 16c, and the negative terminal 40b and the positive terminal 14c are connected by an inter-terminal connection plate 16d.

  As a result, the batteries housed in the battery cases 30, 31, and 32 are connected in series, and the charge / discharge current is supplied to the external power supply or the like via the positive terminal 14 a of the first battery case 30 and the negative terminal 40 a of the third battery case 32. Connect with load.

  By connecting adjacent positive and negative terminals as in this embodiment, the batteries housed in each battery case are connected in series, and the voltage of the battery can be increased.

  However, in this case, it is important from the viewpoint of battery life to make the electrode area of the wound body accommodated in each battery case equal. If the electrode area is different between battery cases, the current density of a battery with a small electrode area will increase, so that the battery will be subjected to a greater load than other batteries, and as a result, deterioration will easily proceed. Because it becomes.

  In the present embodiment, the condition that the electrode areas are equal is realized by equalizing the cross-sectional areas of the annular rings of the annular winding body housed in the battery case.

  In addition, the code | symbols 33 and 34 in FIG. 7 are the space parts between battery cases.

  As described above, the essential parts of the first to third embodiments are the space that surrounds the outer periphery of the first battery case formed between the first battery case and the second battery case, and / or The space surrounding the outer periphery of the second battery case formed between the second battery case and the third battery case is not a member such as a heat radiating plate, but is a space. is there.

  As a result, the weight is increased, the energy density per unit weight and the capacity density are not reduced, a member such as a heat sink is not newly added to the winding part, and the cost is not increased due to an increase in the number of parts.

  Moreover, since members, such as a heat sink, do not interpose between battery cases, external air does not contact a battery case directly and a cooling effect improves. That is, the battery case can be cooled without being affected by the properties (thermal conductivity, etc.) of a member such as a heat sink.

  Moreover, since the space is formed, there is no possibility of a short circuit between the battery cases.

  Furthermore, since it is a space part, the seal location for preventing leakage of the electrolyte does not increase, and the seal area does not increase. Further, the sealing structure is not complicated.

  That is, the essential part of these embodiments is that the cooling medium supplied to the space is formed so as to be in direct contact with the battery case. Thereby, cooling efficiency improves.

  In addition, the essential part of these embodiments is to have a space around the entire periphery of the battery case. Thereby, it becomes possible to cool substantially uniformly over the entire periphery of the battery case, and the battery can be used stably.

  Further, the essential part of these embodiments is to radiate the battery only by forced convection heat transfer.

  In order to make forced convection heat transfer most effective, it is desirable to contact the cooling medium directly or closest to the heating element.

  In these embodiments, without using a member such as a heat sink, the cooling medium can be supplied only to the thin battery case, that is, closest to the winding body, which is a heating element, and forced convection heat is applied. Transmission can be used very effectively.

  In this embodiment, a method for supporting and fixing each battery case will be described.

  FIG. 8 shows a fourth embodiment and is a top plan view of a cylindrical battery in which a support member is inserted between battery cases.

  FIG. 8 includes a first battery case 1 at the center and a second battery case 2 surrounding the outside, and a space 3 is formed between both battery cases.

  A support material 200 is inserted into a part or the whole of the space 3 to support and fix both battery cases.

  A battery may take a rest state between charge and discharge or between discharge and charge during charge and discharge. Since no heat is generated during the resting state, the battery temperature is lower than that during charging / discharging.

  That is, when the charge / discharge cycle is carried out, the temperature also cyclically varies accordingly. At this time, the wound body of the battery also undergoes a volume change and repeats expansion and contraction.

  As a result, the battery case also expands and contracts due to the volume change of the wound body. In particular, the larger the battery, the greater the amount of deformation that occurs in the battery case at the center of the case.

  In this embodiment, the support material 200 absorbs the deformation between the battery cases, thereby preventing damage to the case in the vicinity of the support portion due to the stress generated by the deformation even during a long charge / discharge cycle. Can do.

  As an example of the support member 200, a member that can follow the deformation of the space portion 3 accompanying expansion and contraction of both battery cases, such as a plate spring, a coil spring, an elastic foamable resin, and a mesh-like metal body, is desirable.

  When the entire circumference of the space 3 is filled with the support material 200, it is an absolute condition that the support material 200 can be ventilated.

  FIG. 9 shows a modification of the fourth embodiment, and is an upper plan view of a cylindrical battery in which a support material is partially inserted between battery cases.

  As shown in FIG. 9, when supporting and fixing a part of the space portion 3, it is preferable that air can be ventilated, but the member 201 that cannot vent may be used.

  Further, if the support material 200 or the support material 201 is a material having excellent thermal conductivity, for example, copper or aluminum, the heat from the battery case surface is transmitted to the support material 200 or the support material 201, so that the cooling effect is further increased.

  The reference numerals used in FIGS. 8 and 9 that are not explained in the present embodiment are the same as those explained in FIG.

  Further, in this embodiment, inclusions are formed in the space, but it is not a member related to heat dissipation but is a member that can be ventilated, can be expanded and contracted, and is a support material between the single cells.

  In any of the embodiments described so far, a cylindrical cell has been presented. However, the present embodiment is not limited to a cylindrical shape. Even if the shape of the winding shaft is changed from a cylindrical shape to a rectangular column shape, the effect of the present embodiment is not impaired.

  FIG. 10 is a top plan view showing the outer appearance of the prismatic battery according to the fifth embodiment.

  FIG. 10 shows a plan view of the prismatic battery as viewed from above. The upper side of the battery is the positive electrode side, and the positive terminals 14d and 14e are provided at the upper ends of the hollow battery cases 1A and 2A, respectively. It has been.

  Although not shown, each battery case is provided with a power generation element wound around from the inside to the outside by a square winding shaft.

  In this battery, the central battery case 1A is also hollow, and the space 3A also forms a cooling passage by ventilation. Since the heat radiation area is increased as compared with the case where the battery case is solid, the cooling efficiency is improved.

  Further, a total of four positive terminal connecting plates 16e from each side serve to collect current and support and fix the battery cases 1A and 2A.

  Reference numeral 3B denotes a space portion.

  The present invention relates to a lithium ion secondary battery incorporating a battery structure for releasing heat generated in a large-capacity lithium ion secondary battery, and is a power source for a hybrid vehicle, an electric vehicle, a hybrid railway vehicle, and the like. Moreover, it can be used as an industrial storage battery for power storage.

DESCRIPTION OF SYMBOLS 1,30 1st battery case 2,31 2nd battery case 3 Space part 5,8 Winding body 7 Winding shaft part 14a of 2nd battery case Positive electrode terminal 16a Connection terminal plate 17 for positive electrodes Negative electrode terminal Inter-connection plate 19 Cooling medium 32 Third battery case 50 Battery upper cover 200 Support material

Claims (10)

A lithium ion secondary battery having a positive electrode plate, a negative electrode plate, and a separator,
A first battery case that houses a power generating element body in which the positive electrode plate and the negative electrode plate are laminated via the separator;
A second battery case surrounding the outer periphery of the first battery case and housing the power generation element body;
A lithium ion secondary battery, characterized in that a space is formed between the first battery case and the second battery case and surrounding the outer periphery of the first battery case. The lithium ion secondary battery according to claim 1,
A third battery case surrounding the outer periphery of the second battery case and containing the power generating element body;
A lithium ion secondary battery, characterized in that a space is formed between the second battery case and the third battery case and surrounding the outer periphery of the second battery case. The lithium ion secondary battery according to claim 1 or 2,
The lithium ion secondary battery, wherein the space portion is ventilated with outside air. The lithium ion secondary battery according to claim 1 or 2,
The lithium ion secondary battery, wherein the first battery case is cylindrical or hollow cylindrical. The lithium ion secondary battery according to claim 1 or 2,
The lithium ion secondary battery, wherein the first battery case has a rectangular column shape or a hollow rectangular column shape. The lithium ion secondary battery according to claim 1,
A positive terminal portion and a negative terminal portion formed at both ends of the first battery case; a positive terminal portion and a negative terminal portion formed at both ends of the second battery case;
Positive terminal portions formed at both ends of the first battery case and positive terminal portions formed at both ends of the second battery case, and / or formed at both ends of the first battery case. The lithium ion secondary battery is characterized in that a negative electrode terminal part and negative electrode terminal parts formed at both ends of the second battery case are fixed using a plate-like support material. The lithium ion secondary battery according to claim 2,
A positive terminal portion and a negative terminal portion formed at both ends of the first battery case; a positive terminal portion and a negative terminal portion formed at both ends of the second battery case; and the third battery case. A positive electrode terminal portion and a negative electrode terminal portion formed at both ends of the
Positive terminal portions formed at both ends of the first battery case, positive terminal portions formed at both ends of the second battery case, and positive terminal portions formed at both ends of the third battery case Or / and negative terminal portions formed at both ends of the first battery case, negative terminal portions formed at both ends of the second battery case, and formed at both ends of the third battery case. The lithium ion secondary battery characterized by fixing the negative electrode terminal part made using a plate-shaped support material. The lithium ion secondary battery according to claim 6 or 7,
The lithium ion secondary battery, wherein the plate-like support member is a current collecting terminal member. The lithium ion secondary battery according to claim 1,
A member that can be ventilated and contracted is inserted into the space,
The member is bonded or fixed to the outer wall surface of the first battery case that forms the inner periphery of the space portion and the inner wall surface of the second battery case that forms the outer periphery of the space portion. The lithium ion secondary battery characterized by the above-mentioned. The lithium ion secondary battery according to claim 2,
A member that can be ventilated and contracted is inserted into the space,
The member includes an outer wall surface of the first battery case that forms an inner periphery of the space portion, an inner wall surface of the second battery case that forms an outer periphery of the space portion, and an inner surface of the space portion. Lithium ion secondary characterized in that it is bonded or fixed to the outer wall surface of the second battery case that forms a periphery and the inner wall surface of the third battery case that forms the outer periphery of the space portion. battery.

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