JP7099989B2 - Method of manufacturing secondary batteries and secondary batteries - Google Patents

Description

The present invention relates to a secondary battery that generates heat by charging and discharging, and a method for manufacturing the secondary battery.

As is well known, a secondary battery such as a lithium ion secondary battery is used as a power source for portable electronic devices and as a power source for electric vehicles and hybrid vehicles. For example, a lithium ion secondary battery is configured by accommodating a group of electrode plates in which a positive electrode plate and a negative electrode plate are laminated via a separator in a battery case together with a non-aqueous electrolyte solution containing a lithium-containing electrolyte.

The battery performance of such a secondary battery deteriorates when the battery temperature rises due to a decrease in heat dissipation due to a high environmental temperature or an increase in the amount of heat generated by charging / discharging with a large current. Therefore, Patent Document 1 describes an example of a secondary battery having improved heat dissipation.

The secondary battery described in Patent Document 1 is a laminated battery, and has a group of electrode plates (electrode laminated body) in which positive electrode plates and negative electrode plates are alternately laminated via a separator. .. The battery case (exterior) seals and stores the electrolytic solution (electrolyte) together with the electrode plates. The electrode plate group includes a penetrating portion that penetrates the upper surface side and the lower surface side in the stacking direction. The battery case is provided with a recess recessed in the penetrating direction of the penetrating portion at a position corresponding to the penetrating portion of the electrode plate group to be stored.

Japanese Unexamined Patent Publication No. 2007-18917

In recent years, as a battery performance, a power source for driving a vehicle is required to be able to maintain and expand the battery capacity, expand the usage environment, and perform large charge / discharge.
The secondary battery or the like described in Patent Document 1 has improved heat dissipation, but there is a risk that the battery capacity will decrease as the electrode mixture decreases due to the through holes provided in the electrode plate group. On the other hand, in a secondary battery or the like, if the through hole is made smaller or smaller in order to maintain the battery capacity, the heat dissipation property is lowered, the battery temperature rises significantly, and the battery performance may be lowered.

The present invention has been made in view of such circumstances, and an object thereof is to manufacture a secondary battery and a secondary battery capable of suppressing a decrease in battery performance due to an increase in battery temperature while maintaining a battery capacity. To provide a method.

The secondary battery that solves the above-mentioned problems has a secondary electrode plate group in which a first electrode plate and a second electrode plate that is electrically paired with the first electrode plate are alternately laminated via a separator. In the battery, the first electrode plate has a first electrode mixture layer on a part of the first base material, and the second electrode plate has a second electrode mixture on a part of the second base material. The plate surface of the first base material having a layer is wider than the plate surface of the second base material, and the two first electrode plates sandwiching the second electrode plate are laminated unevenly in the surface direction. The two first electrode mixture layers are sandwiched between the two first electrode plates in an overlapping range that coincides with the stacking direction. The entire range of the second electrode mixture layer of the second electrode plate is included.

A method for manufacturing a secondary battery for solving the above problems is to form a group of electrode plates in which a first electrode plate and a second electrode plate electrically paired with the first electrode plate are alternately laminated via a separator. A method for manufacturing a secondary battery, wherein the first electrode plate has a first electrode mixture layer as a part of a first base material, and the second electrode plate is a part of a second base material. The first electrode plate has a second electrode mixture layer, and the plate surface of the first electrode plate is wider than the plate surface of the second electrode plate. The entire range of the second electrode mixture layer of the second electrode plate sandwiched between the two first electrode plates is included in the overlapping range in which the two first electrode mixture layers coincide with each other in the stacking direction. At the same time, it is provided with a laminating step of providing a non-corresponding range in which the laminating direction does not match by laminating with a bias in the plane direction.

Usually, in the electrode plate group, the first electrode plates and the like are stacked so that the outer circumferences are aligned in the stacking direction, so that the first electrode plates and the like are stacked substantially straight in the stacking direction.
On the other hand, according to such a configuration or method, the plate surfaces of the two first electrode plates are unevenly stacked, that is, stacked laterally. Therefore, the two adjacent first electrode plates have a non-correspondence range in which they do not match in the stacking direction. This non-corresponding range is an open range in which at least one direction of the plate surface does not face the other plate surface in the stacking direction, and therefore has higher heat dissipation performance than the range facing the other plate surface. Will be. Therefore, it is possible to suppress the deterioration of the battery performance due to the increase in the battery temperature while maintaining the battery capacity.

Further, even if the two first electrode plates are laterally offset and laminated, the entire range of the second electrode mixture layer of the second electrode plate sandwiched between them covers the first electrode combination of both first electrode plates. Since it faces the material layer, ion transfer can be performed between the first electrode plate and the second electrode plate in the same manner as in the conventional case, so that there is no possibility that the battery performance is deteriorated.

As a preferred configuration, the three or more first electrode plates are offset and deviated in the same direction when viewed from the stacking direction.
According to such a configuration, the plurality of first electrode plates are displaced and deviated in a certain direction when viewed from the stacking direction. That is, the first electrode plates have lateral displacement and are displaced and stacked. As a result, a non-corresponding range is secured for each first electrode plate, and an increase in battery temperature is suppressed.

As a preferred configuration, the first electrode plate is a negative electrode plate and the second electrode plate is a positive electrode plate.
According to such a configuration, in a secondary battery in which the negative electrode plate is larger than the positive electrode plate, the heat dissipation property of the negative electrode plate can be enhanced.

As a preferred configuration, the two separators sandwiching the first electrode plate are laminated so that their outer sides are aligned in the stacking direction.
According to such a configuration, one first electrode plate (for example, one negative electrode plate) and two separators can be treated as a set. For example, the first electrode plates housed in the separator can be laminated so as to have lateral deviation.

As a preferred configuration, the two separators sandwiching the first electrode plate are laminated with their surfaces deviated in the plane direction so as to have a non-corresponding range in which they do not match in the stacking direction.
According to such a configuration, the separator is laminated together with the first electrode plate so as to have an deviation, so that the size of the separator can be adjusted to secure the insulation between the first electrode plate and the second electrode plate sandwiching the separator. It can be reduced to the required size.

As a preferable configuration, in the electrode plate group, the first electrode plate located at the end from the center in the stacking direction is displaced in the same direction and is deviated.
According to such a configuration, the electrode plates are biased from the center to both ends in the same direction, that is, a so-called V-shape. As a result, the amount of deviation of the electrode plate group is integrated from the center to the end, so that the amount of deviation can be suppressed compared to the integration of continuous deviation from one end to the other, and heat dissipation performance. Can be secured.

As a preferred method, in the laminating step, at least one of the second electrode plate and the separator is further biased and laminated in the same direction as the two first electrode plates.
According to such a method, since at least one of the second electrode plate and the separator is biased in the same direction as the first electrode plate, it is easy to stack a plurality of first electrode plates so as to have the deviation. be. In addition, the inclination of the end portions of the laminated electrode plates with respect to the stacking direction becomes gentle.

According to the present invention, it is possible to suppress a decrease in battery performance due to an increase in battery temperature while maintaining a battery capacity.

The figure which shows the outline of the perspective structure about one Embodiment which embodied the secondary battery. The schematic diagram explaining the structure of the electrode plate group in the same embodiment. FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 1 of the secondary battery in the same embodiment. FIG. 3 is a partial cross-sectional view of FIG. 3 for explaining the structure of the electrode plate group in the same embodiment. The figure which shows the heat dissipation performance of the electrode plate group in the same embodiment. The schematic diagram explaining the measurement of the heat dissipation performance of the electrode plate group in the same embodiment.

An embodiment of the secondary battery will be described with reference to FIGS. 1 to 6. In the following, an example in which the secondary battery is embodied as a lithium ion secondary battery will be described.
As shown in FIG. 1, the secondary battery 11 includes a case 12 having an opening and a lid portion 13 for sealing the opening of the case 12. The case 12 and the lid 13 form a battery case. The case 12 and the lid 13 are made of a metal material. The lid portion 13 is provided with a positive electrode current collector 20 including a positive electrode terminal 21 and a negative electrode current collector 30 including a negative electrode terminal 31. The case 12 contains a rectangular cuboid plate group 14 and an electrolytic solution. The lid portion 13 is provided with a discharge portion 32 for discharging the gas in the battery case according to the internal pressure of the battery case, and an injection hole 33 for injecting the electrolytic solution.

As shown in FIG. 2, the electrode plate group 14 is a laminated body in which a plurality of positive electrode plates 15 and a plurality of negative electrode plates 16 are alternately laminated via a separator 17. The negative electrode plate 16 constitutes a first electrode plate, and the positive electrode plate 15 constitutes a second electrode plate that is electrically paired with the negative electrode plate 16.

The positive electrode plate 15 has a rectangular shape and has four outer periphery, and also has a positive electrode base material 18 as a second base material and a second electrode provided on a part of both sides of the positive electrode base material 18. The positive electrode mixture layer 19 constituting the mixture layer is included. The positive electrode base material 18 is formed of a metal foil (or a thin metal plate) and is formed into a rectangular shape (rectangular shape). The positive electrode base material 18 has a positive electrode tab 18A (current collecting tab) extending from the upper end of the upper end and the lower end corresponding to the long side. The positive electrode tab 18A is not provided with a positive electrode mixture. The positive electrode tab 18A is provided at a position of the upper end deviated from the center of the long side by a predetermined distance toward one side (left side in FIG. 2).

The material constituting the positive electrode base material 18 includes, for example, aluminum or an aluminum alloy. The material constituting the positive electrode mixture includes a lithium-containing composite oxide which is a positive electrode active material, a binder, a conductive agent and the like.

The negative electrode plate 16 has a rectangular shape and has four outer periphery, and also has a negative electrode base material 23 as a first base material and a first electrode provided on a part of both sides of the negative electrode base material 23. The negative electrode mixture layer 24 constituting the mixture layer is included. The negative electrode base material 23 is formed of a metal foil (or a thin metal plate) and is formed into a rectangular shape (rectangular shape). The negative electrode base material 23 has a negative electrode tab 23A (current collector tab) extending from the upper end of the upper end and the lower end corresponding to the long side. The negative electrode tab 23A is not provided with a negative electrode mixture. The negative electrode tab 23A is provided at a position of the upper end deviated from the center of the long side by a predetermined distance toward the other side (right side in FIG. 2).

The material constituting the negative electrode base material 23 includes, for example, copper and nickel. The material constituting the negative electrode mixture includes particles containing a negative electrode active material, a binder, a conductive agent, and the like. The negative electrode active material is a material that can occlude and release lithium, and is, for example, carbon such as graphite, metallic lithium, or a lithium alloy.

The positive electrode plates 15 are laminated in a state where the positions of the positive electrode tabs 18A are aligned. That is, the positive electrode tabs 18A are stacked so as to be arranged at the upper end of the positive electrode base material 18 and at a position closer to one side from the center in the width direction. Therefore, the positive electrode tabs 18A of the plurality of positive electrode plates 15 are collected in a bundle to form a positive electrode tab group.

The negative electrode plates 16 are laminated in a state where the positions of the negative electrode tabs 23A are aligned. That is, the negative electrode tabs 23A are stacked so as to be arranged at the upper end of the negative electrode base material 23 and at a position closer to the other side from the center in the width direction. Therefore, the negative electrode tabs 23A of the plurality of negative electrode plates 16 are collected in a bundle to form a negative electrode tab group.

In this way, by locating the positive electrode tab group and the negative electrode tab group at the same end of the electrode plate group 14, the positive electrode tab is not provided at different ends as in the case of a wound type electrode body. The space occupied by the group and the negative electrode tab group can be reduced. The electrode plate group 14 does not include the positive electrode tab group and the negative electrode tab group.

Further, the plate surface of the negative electrode plate 16 is wider than the plate surface of the positive electrode plate 15. Therefore, the negative electrode base material 23 has a larger outer shape than the positive electrode base material 18. Further, the negative electrode mixture layer 24 is wider than the positive electrode mixture layer 19.

The separator 17 is a film made of a rectangular sheet made of an insulating material, has outer periphery on four sides, and has an outer shape larger than that of the positive electrode plate 15 and the negative electrode plate 16. The separator 17 is a porous polyolefin film for holding an electrolytic solution between the positive electrode plate 15 and the negative electrode plate 16, a porous polymer film such as a porous polyvinyl chloride film, or a lithium ion or ionic conductive polymer electrolyte. The membranes can also be used alone or in combination. The separator 17 is also arranged in the frontmost layer and the last layer in the stacking direction in the electrode plate group 14.

The electrolytic solution is a non-aqueous electrolyte solution containing a lithium-containing electrolyte, and is a composition in which a supporting salt is contained in a non-aqueous solvent. As the non-aqueous solvent, propylene carbonate (PC) or the like can be used. As the supporting salt, a lithium compound (lithium salt) such as LiPF ₆ can be used.

The structure of the electrode plate group 14 will be described with reference to FIGS. 3 and 4. In FIGS. 3 and 4, for convenience of illustration, spaces are provided between the positive electrode plate 15 and the separator 17 and between the negative electrode plate 16 and the separator 17, but they are laminated as the electrode plate group 14. The positive electrode plate 15 and the separator 17 are in contact with each other, and the negative electrode plate 16 and the separator 17 are in contact with each other.

As shown in FIG. 3, the electrode plate group 14 includes a lower end portion 141 facing the bottom surface 121 of the case 12 on the lower side and an upper end portion 145 facing the lid portion 13 on the upper side in the cross section in the stacking direction. The lower end portion 141 has a lowest point 142 at the central BC in the stacking direction, and has shapes L11 and L12 rising from the central BC toward the end portion in the stacking direction, so-called V-shaped shapes. Similarly, the upper end portion 145 has a lowest point 146 at the central BC in the stacking direction, and has shapes L21 and L22 rising from the central BC toward the end portion in the stacking direction, so-called V-shaped shapes. That is, the positive electrode plate 15, the negative electrode plate 16, and the separator 17 constituting the electrode plate group 14 are laminated with the upper side deviated by a predetermined amount of deviation in the plate surface direction. Further, between the central BC of the electrode plate group 14 and the end portion in the stacking direction, the displacement directions are the same, the deviation amount of the two adjacent negative electrode plates 16 and the deviation amount of the two adjacent positive electrode plates 15. , And two adjacent separators 17 have the same displacement.

For example, in the manufacturing process of the secondary battery 11, the electrode plate group 14 is manufactured by laminating two negative electrode plates 16 so as to sandwich the positive electrode plate 15 (lamination step).
More specifically, in the laminating step, the two negative electrode plates 16 sandwiching the positive electrode plate 15 are deviated and laminated so that the two negative electrode mixture layers 24 have an overlapping range that coincides with the laminating direction. Further, the overlapping range includes the entire range of the positive electrode mixture layer 19 of the positive electrode plate 15 sandwiched between the two negative electrode plates 16. As a result, the two negative electrode plates 16 are provided with a non-corresponding range in which they do not match in the stacking direction. The non-corresponding range is preferably a portion of the negative electrode base material 23 where the negative electrode mixture layer 24 is not provided.

Further, in this laminating step, the positive electrode plate 15 and the separator 17 are laminated in the same direction as the two negative electrode plates 16.
FIG. 4 is an enlarged view of a part of the electrode plate group 14. For convenience of explanation, the first positive electrode plate 151, the first separator 171 and the first negative electrode plate 161 and the second separator 172, the second positive electrode plate 152, the third separator 173, and the second negative electrode are arranged in this order from the left to the right in FIG. It is a plate 162. Therefore, the first positive electrode plate 151 and the first negative electrode plate 161 are laminated via the first separator 171 and the first negative electrode plate 161 and the second positive electrode plate 152 are laminated via the second separator 172. The second positive electrode plate 152 and the second negative electrode plate 162 are laminated via the separator 173. For example, the electrode plate group 14 has a structure in which the first negative electrode plate 161 and the second negative electrode plate 162 as the two negative electrode plates 16 sandwich the second positive electrode plate 152.

The first positive electrode plate 151 and the second positive electrode plate 152 have an arrangement position of the lower end along the line L12P and an arrangement position of the upper end along the line L22P. The line L12P is provided parallel to and above the lower end portion 141 of the electrode plate group 14. The line L22P is provided parallel to and below the upper end portion 145 of the electrode plate group 14. The first positive electrode plate 151 and the second positive electrode plate 152 have the same length in the vertical direction. That is, the lower end P12 of the second positive electrode plate 152 is laminated with the lower end P11 of the first positive electrode plate 151 displaced upward by the positive electrode deviation amount PS. Similarly, the upper end P22 of the second positive electrode plate 152 is laminated with the upper end P21 of the first positive electrode plate 151 displaced upward by the positive electrode deviation amount PS.

The first negative electrode plate 161 and the second negative electrode plate 162 have an arrangement position of the lower end along the line L12M and an arrangement position of the upper end along the line L22M. The line L12M is provided parallel to and above the lower end portion 141 of the electrode plate group 14. The line L22M is provided parallel to and below the upper end portion 145 of the electrode plate group 14. The first negative electrode plate 161 and the second negative electrode plate 162 have the same length in the vertical direction. That is, the lower end M12 of the second negative electrode plate 162 is laminated with the lower end M11 of the first negative electrode plate 161 displaced upward by the negative electrode deviation amount MS. Similarly, the upper end M22 of the second negative electrode plate 162 is laminated with the upper end M21 of the first negative electrode plate 161 displaced upward by the negative electrode deviation amount MS.

The negative electrode deviation amount MS is the same as the positive electrode deviation amount PS.
The right side of the lower end of the first negative electrode plate 161 is deviated from the lower end of the second negative electrode plate 162 adjacent to the right by the negative electrode deviation amount MS, and does not overlap with the lower ends of the other negative electrode plates 16 on the right in the stacking direction. .. Therefore, the first negative electrode plate 161 has a non-corresponding range corresponding to the negative electrode deviation amount MS at the lower end. Similarly, a non-corresponding range is provided for the lower end of the second negative electrode plate 162. The non-corresponding range is a range in which the two first negative electrode plates 161 and the second negative electrode plates 162 are stacked unevenly so that they do not match in the stacking direction.

The left upper end of the second negative electrode plate 162 is displaced by the negative electrode deviation amount MS from the upper end of the first negative electrode plate 161 adjacent to the left, and does not overlap with the upper ends of the other negative electrode plates 16 on the left in the stacking direction. .. Therefore, the second negative electrode plate 162 has a non-corresponding range corresponding to the negative electrode deviation amount MS at the upper end. Similarly, a non-corresponding range is provided for the upper end of the first negative electrode plate 161.

By the way, the non-corresponding range is an open range in which at least one direction of the plate surface of the first negative electrode plate 161 and the second negative electrode plate 162 does not face the plate surface of the other negative electrode plate 16. The open range has higher heat dissipation performance than the unopened range in which both sides face the plate surface of the other negative electrode plate 16.

Further, the electrode plate group 14 has an overlapping range in which the negative electrode mixture layer 24 of the first negative electrode plate 161 and the negative electrode mixture layer 24 of the second negative electrode plate 162 coincide with each other in the stacking direction. Further, the electrode plate group 14 includes the entire range of the positive electrode mixture layer 19 of the second positive electrode plate 152 sandwiched between the first negative electrode plate 161 and the second negative electrode plate 162 in the overlapping range corresponding to the stacking direction. ing.

In the first separator 171 to the third separator 173, the arrangement position of the lower end is along the shape L12 of the lower end portion 141 of the electrode plate group 14, and the arrangement position of the upper end is along the shape L22 of the upper end portion 145 of the electrode plate group 14. The first separator 171 to the third separator 173 have the same length in the vertical direction. That is, the second separator 172 is laminated with the separator deviation amount SS1 displaced upward with respect to the first separator 171 and the third separator 173 is displaced upward by the separator deviation amount SS2 with respect to the second separator 172. It is laminated. The separator deviation amount SS1 at the lower end of the first separator 171 constitutes the non-corresponding range, and the separator deviation amount SS2 at the lower end of the second separator 172 constitutes the non-corresponding range. The non-corresponding range here is a range in which the two separators 17 are stacked unevenly so that they do not match in the stacking direction.

The length obtained by adding the separator deviation amount SS1 and the separator deviation amount SS2 is the same as the positive electrode deviation amount PS and the negative electrode deviation amount MS. For example, if the ratio of the length of the separator deviation amount SS1 to the length of the separator deviation amount SS2 is 1: 1, each is half the length of the positive electrode deviation amount PS. The ratio between the length of the separator deviation amount SS1 and the length of the separator deviation amount SS2 may be changed in consideration of the ratio between the thickness of the positive electrode plate 15 and the thickness of the negative electrode plate 16.

The temperature of the electrode plate group 14 will be described with reference to FIGS. 5 and 6.
The temperature of the electrode plate group 14 rises due to charging and discharging, but if the heat dissipation performance is high, the temperature is kept low, and if the heat dissipation performance is low, the temperature is kept high. At this time, it was found that the heat dissipation performance of the electrode plate group 14 changes depending on the amount of deviation when the first negative electrode plate 161 and the second negative electrode plate 162 are laminated, that is, the so-called shift width.

As shown in FIG. 4, the shift width corresponds to the negative electrode deviation amount MS, and defines the width of the non-corresponding range of the negative electrode plate 16 in which high heat dissipation performance is ensured. When the shift width is large, the electrode plate group 14 has higher heat dissipation performance as the non-correspondence range becomes wider, and conversely, when the shift width becomes smaller, heat dissipation corresponds to the narrower non-correspondence range. Performance will be low.

With reference to FIG. 5, when the shift width is “0 mm”, the negative electrode plates 16 are laminated without being biased, which is the so-called conventional electrode plate group 14. In the negative electrode plate 16 having a shift width of "0 mm", the lower ends and the upper ends of the negative electrode plate 16 are aligned in the stacking direction. When the shift width is "0.5 mm", the negative electrode plates 16 are the electrode plate group 14 in which the negative electrode plates 16 are deviated by "0.5 mm" and laminated, and the lower and upper ends of the negative electrode plates 16 are "0.5 mm" in the plate surface direction. It is biased one by one. When the shift width is "1.0 mm", the negative electrode plates 16 are a group of electrode plates 14 in which the negative electrode plates 16 are deviated by "1.0 mm" and laminated, and the lower and upper ends of the negative electrode plates 16 are "1.0 mm" in the plate surface direction. It is biased one by one.

Then, the temperature measurement results of each of the electrode plate groups 14 having different shift widths were obtained after being stored in a high temperature environment and then placed in a low temperature environment for a predetermined time.
As shown in FIG. 5, as a temperature measurement result of "temperature after 15 minutes", when the shift width is "0 mm", it is "35.2 ° C", and when the shift width is "0.5 mm", it is "34.6". When "° C." and the shift width were "1.0 mm", "34.1 ° C." was obtained.

According to this, when the shift width is "0.5 mm", the "temperature after 15 minutes" is "0.6 ° C" lower than the shift width "0 mm" and "2%" with respect to the relative temperature difference. The temperature dropped. In other words, the heat dissipation performance was "2%" higher than the relative temperature difference.

Further, the "temperature after 15 minutes" is "1.1 ° C" lower than the shift width "0 mm" when the shift width is "1.0 mm", and is "3.7%" with respect to the relative temperature difference. The temperature has dropped. In other words, the heat dissipation performance was "3.7%" higher than the relative temperature difference.

The measuring method will be described in detail with reference to FIG.
A set of electrode plates was arranged on the left and right sides of one negative electrode plate 16 to prepare a group of electrode plates 14 for temperature measurement. The set of electrode plates is a stack of a separator 17, a positive electrode plate 15, a separator 17, and a negative electrode plate 16.

Then, the electrode plate group 14 for temperature measurement is housed in the nylon bag 40. The plate group 14 for temperature measurement housed in the nylon bag 40 was first stored in a constant temperature bath 50 at 55 ° C. for 30 minutes. Subsequently, the temperature when stored for 15 minutes in a constant temperature bath 50 at 25 ° C. having a relative temperature difference of 30 ° C. was measured at the center 36 in the stacking direction of the electrode plate group 14 for temperature measurement, and this was measured. Obtained as a measurement result.

The effect of this embodiment will be described.
(1) The plate surfaces of the two negative electrode plates 16 are unevenly stacked, that is, they are stacked laterally. Therefore, the two adjacent negative electrode plates 16 have a non-corresponding range in which they do not match in the stacking direction. This non-corresponding range is an open range in which at least one direction of the plate surface does not face the other plate surface in the stacking direction, and therefore has higher heat dissipation performance than the range facing the other plate surface. .. Therefore, it is possible to suppress the deterioration of the battery performance due to the increase in the battery temperature while maintaining the battery capacity.

Further, even if the two negative electrode plates 16 are laterally offset and laminated, the entire range of the positive electrode mixture layer 19 of the positive electrode plate 15 sandwiched between them faces the negative electrode mixture layer 24 of both negative electrode plates 16. Therefore, since the same ion transfer as in the conventional case is possible between the negative electrode plate 16 and the positive electrode plate 15, there is no possibility that the battery performance is deteriorated.

(2) The plurality of negative electrode plates 16 are displaced and biased in a certain direction when viewed from the stacking direction. That is, the negative electrode plates 16 have lateral displacement and are displaced and stacked. As a result, a non-corresponding range is secured for each negative electrode plate 16, and an increase in battery temperature is suppressed.

(3) In the secondary battery 11 in which the negative electrode plate 16 is larger than the positive electrode plate 15, the heat dissipation property of the negative electrode plate 16 can be enhanced.
(4) The separator 17 is laminated together with the negative electrode plate 16 so as to have an deviation, so that the size of the separator 17 is the size necessary for ensuring the insulation between the negative electrode plate 16 sandwiching the separator 17 and the positive electrode plate 15. Can be suppressed to.

(5) The electrode plate group 14 has a so-called V-shape that is biased in the same direction from the central BC to both ends. As a result, the amount of deviation of the electrode plate group 14 is integrated from the central BC to the end, so that the amount of deviation can be suppressed as compared with the accumulation of continuous deviation from one end to the other. The heat dissipation performance can be ensured.

(6) Since at least one of the positive electrode plate 15 and the separator 17 is biased in the same direction as the negative electrode plate 16, it is easy to stack the plurality of negative electrode plates 16 so as to have the bias. Further, the inclination of the end portion of the laminated electrode plate group 14 with respect to the stacking direction becomes gentle.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-In the above embodiment, in the laminating step, a case where the positive electrode plate 15 and the separator 17 are deviated in the same direction as the two negative electrode plates 16 and laminated is illustrated. However, the present invention is not limited to this, and when at least one of the positive electrode plate and the separator is laminated, a part of the lamination may not be biased in the same direction as the negative electrode plate.

In the above embodiment, the case where the electrode plate group 14 is deflected upward from the central BC in the stacking direction toward the end portion of the negative electrode plate 16 is illustrated. However, the present invention is not limited to this, and the negative electrode plate may be displaced upward from one end of the electrode plate group toward the other end in the stacking direction.

In the above embodiment, the case where the electrode plate group 14 is displaced upward from the central BC in the stacking direction toward the end portion of the electrode plate group 14 is illustrated. However, the present invention is not limited to this, and the electrode plate group may change the direction in which the negative electrode plate deviates from the center to the end portion once or more. For example, in the electrode plate group, the shape of the lower end portion may be jagged in the vertical direction between the center and the end portion.

In the above embodiment, the case where the lower end of the first separator 171 to the third separator 173 is arranged along the shape L12 of the lower end portion 141 of the electrode plate group 14 is illustrated. However, the present invention is not limited to this, and since the two separators sandwiching the negative electrode plate are not biased to each other, the two separators sandwiching the negative electrode plate may be laminated in such a manner that the outer sides sandwiching the negative electrode plate are aligned in the stacking direction. At this time, the two separators sandwiching the negative electrode plate do not have a non-corresponding range, while the negative electrode deviation amount of the two negative electrode plates corresponds to the distance between the two separators sandwiching the adjacent negative electrode plates. It will have a non-corresponding range.

Thereby, one electrode plate (for example, one negative electrode plate) and two separators can be treated as a set. For example, the negative electrode plates housed in the bag-shaped separator can be laminated so as to have an deviation based on the position of the negative electrode plate.

-In the above embodiment, the case where the negative electrode plate 16 constitutes the first electrode plate and the positive electrode plate 15 constitutes the second electrode plate is illustrated. However, the present invention is not limited to this, and the first electrode plate may be the positive electrode plate and the second electrode plate may be the negative electrode plate as long as the plate surface of the positive electrode plate is wider than the plate surface of the negative electrode plate.

-In the above embodiment, a case where a plurality of negative electrode plates 16 are biased with the same negative electrode deviation amount MS is illustrated. However, the present invention is not limited to this, and the amount of negative electrode deviation may differ depending on the position in the stacking direction as long as appropriate heat dissipation performance can be obtained.

In the above embodiment, the case where the negative electrode plates 16 are unevenly laminated over the entire lower end portion 141 of the electrode plate group 14 is illustrated. However, the present invention is not limited to this, and the negative electrode plate may be biased in a part of the lower end portion of the electrode plate group. This also enhances the heat dissipation performance from the electrode plate group. For example, the central portion where it is difficult to dissipate heat may be biased.

-The polar mixture may be located on at least one surface of the substrate, and may be located on only one surface of the substrate.
-In the above embodiment, the case where the positive electrode plate 15, the negative electrode plate 16, and the separator 17 are rectangular is illustrated. However, the present invention is not limited to this, and the positive electrode plate, the negative electrode plate, and the separator may be any other rectangular shape such as a square shape as long as they can form the electrode plate of the secondary battery.

The shapes of the positive electrode tab 18A and the negative electrode tab 23A are appropriately set according to the shape of the non-aqueous battery and the like, and can be changed to other shapes.
-In the above embodiment, the secondary battery 11 has a structure having one electrode plate group 14 in the case 12, but may have a structure having a plurality of electrode plate groups in the case 12. For example, a plurality of electrode plates are connected in series in the case 12.

-In the above embodiment, the case where the secondary battery 11 is a lithium ion secondary battery is exemplified. However, the present invention is not limited to this, and the secondary battery may be a secondary battery of another non-aqueous electrolyte, or may be a secondary battery of an aqueous electrolyte such as a nickel hydrogen secondary battery. For example, a nickel-hydrogen secondary battery is provided with a positive electrode plate having a positive electrode mixture containing nickel hydroxide or the like on a base material made of nickel metal or the like, and a negative electrode mixture containing a hydrogen storage alloy on the base material made of a metal material. It has a group of electrode plates in which a negative electrode plate and a negative electrode plate are laminated via a separator.

-The secondary battery 11 may be used for vehicles such as electric vehicles, hybrid vehicles, gasoline vehicles and diesel vehicles, and other moving bodies. Alternatively, it may be fixedly installed.

11 ... secondary battery, 12 ... case, 13 ... lid, 14 ... electrode plate group, 15 ... positive electrode plate, 16 ... negative electrode plate, 17 ... separator, 18 ... positive electrode base material, 18A ... positive electrode tab, 19 ... positive electrode combination Material layer, 20 ... Positive electrode current collector, 21 ... Positive electrode terminal, 23 ... Negative electrode base material, 23A ... Negative electrode tab, 24 ... Negative electrode mixture layer, 30 ... Negative electrode current collector, 31 ... Negative electrode terminal, 32 ... Discharge section, 33 ... Injection hole, 36 ... Center in stacking direction, 40 ... Nylon bag, 50 ... Constant temperature bath, 121 ... Bottom surface, 141 ... Lower end, 142 ... Bottom point, 145 ... Top, 146 ... Bottom point, 151 ... No. 1 positive electrode plate, 152 ... second positive electrode plate, 161 ... first negative electrode plate, 162 ... second negative electrode plate, 171 ... first separator, 172 ... second separator, 173 ... third separator.

Claims (8)

A rectangular first electrode plate having four outer perimeters and a rectangular second electrode plate having four outer perimeters electrically paired with the first electrode plate are interposed via a separator. It is a secondary battery having a group of electrode plates stacked alternately, and is a secondary battery.
The first electrode plate has a first electrode mixture layer as a part of the first base material, and has a first current collecting tab extending to the upper end of the first electrode plate .
The second electrode plate has a second electrode mixture layer as a part of the second base material, and has a second current collecting tab extending to the upper end of the second electrode plate .
The plate surface of the first base material is wider than the plate surface of the second base material.
The two first electrode plates sandwiching the second electrode plate have a non-correspondence range in which the stacking directions are inconsistent due to the stacking of the first electrode plates being offset up and down along the plane direction, and the two first electrode plates are laminated. A secondary battery in which the entire range of the second electrode mixture layer of the second electrode plate sandwiched between the two first electrode plates is included in the overlapping range in which the electrode mixture layer coincides with the stacking direction. The secondary battery according to claim 1, wherein the three or more first electrode plates are offset and deviated in the same direction when viewed from the stacking direction. The first electrode plate is a negative electrode plate, and the first electrode plate is a negative electrode plate.
The secondary battery according to claim 1 or 2, wherein the second electrode plate is a positive electrode plate. The secondary battery according to any one of claims 1 to 3, wherein the two separators sandwiching the first electrode plate are laminated so that their outer sides are aligned in the stacking direction. According to any one of claims 1 to 3, the two separators sandwiching the first electrode plate are laminated with their surfaces deviated in the surface direction so as to have a non-correspondence range in which they do not match in the stacking direction. The described secondary battery. The secondary battery according to any one of claims 1 to 5, wherein the electrode plate group is offset from the center of the stacking direction to the end of the first electrode plate in the same direction. A rectangular first electrode plate having four outer perimeters and a rectangular second electrode plate having four outer perimeters electrically paired with the first electrode plate are interposed via a separator. It is a method of manufacturing a secondary battery having a group of electrode plates stacked alternately.
The first electrode plate has a first electrode mixture layer as a part of the first base material, and has a first current collecting tab extending to the upper end of the first electrode plate .
The second electrode plate has a second electrode mixture layer as a part of the second base material, and has a second current collecting tab extending to the upper end of the second electrode plate .
The plate surface of the first electrode plate is wider than the plate surface of the second electrode plate.
The second electrode plate sandwiching the second electrode plate is sandwiched between the two first electrode plates in an overlapping range in which the two first electrode mixture layers coincide with each other in the stacking direction. It is provided with a laminating step of providing a non-corresponding range in which the laminating direction does not match by laminating the electrode plate so as to include the entire range of the second electrode mixture layer while being deviated up and down along the plane direction. Next battery manufacturing method. The method for manufacturing a secondary battery according to claim 7, wherein the laminating step further comprises laminating at least one of the second electrode plate and the separator in the same direction as the two first electrode plates.

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