JP6028916B2 - Secondary battery - Google Patents

Description

  The present invention relates to a secondary battery.

  2. Description of the Related Art Conventionally, secondary batteries such as lithium ion secondary batteries have been used as motor driving batteries mounted on electric vehicles such as electric vehicles and plug-in hybrid electric vehicles. In the lithium ion secondary battery, lithium ions move between the electrodes as movable ions during charge / discharge, and no chemical reaction occurs during charge / discharge, so the concentration of the electrolyte does not change. A lithium ion secondary battery in which metal ions move as movable ions during charging in this way is called a rocking chair type secondary battery.

  By the way, the secondary battery mounted on an electric vehicle has excellent output characteristics that respond to large current output for climbing, accelerating, and driving at low temperatures, and excellent input characteristics that respond to large current input during rapid charging and regeneration. In addition, high energy capacity characteristics that can be driven for a long time are required.

  In order to improve the input / output characteristics of such a lithium ion secondary battery, a lithium ion secondary battery in which the electrode material is adjusted so that the resistance ratio between the positive electrode and the negative electrode falls within a predetermined range has been proposed (for example, patents). Reference 1).

JP 2011-187186 A

  However, even if such a lithium ion secondary battery is mounted on an electric vehicle, there is a possibility that sufficient output cannot be achieved when high output is required such as when the accelerator is fully opened. On the other hand, if only the output performance of the lithium ion secondary battery is improved, the capacity of the lithium ion secondary battery is reduced and the travel distance is shortened.

  In addition, although such a problem is a remarkable problem especially in a vehicle-mounted lithium ion secondary battery, it is not limited to a vehicle-mounted secondary battery, It is not limited to a lithium ion secondary battery. .

  Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to provide a secondary battery having high output performance.

The secondary battery according to the present invention includes a current collector foil and an electrode body having an active material layer provided on the current collector foil, and a secondary battery using metal ions contained in the active material layer as movable ions. The active material layer is a first active material layer provided on the current collector foil, and the current collector foil of the first active material layer is a second active material layer provided on the other side. The first active material layer has a higher capacity than the second active material layer; the second active material layer has a higher output than the first active material layer; The two active material layers are characterized in that a plurality of conductive members that penetrate the first active material layer and connect the current collector foil and the second active material layer are provided intermittently in the plane direction. .

  In the present invention, since the second active material layer is connected to the current collector foil, the output performance is reduced even if the first active material layer is interposed between the second active material layer and the current collector foil. Can be suppressed. In addition, since the first active material layer and the second active material layer have different characteristics, the characteristics can be supplemented with each other.

The first active material layer of the current collector foil side is higher capacity than the second active material layer on the other side, the second active material layer is a higher power than the first active material layer By being configured in this way, it is possible to improve the output while maintaining the capacity.

  As a preferred embodiment of the present invention, the active material layer may be a positive electrode active material layer containing a positive electrode active material constituting a positive electrode.

As preferable embodiment of this invention, it is mentioned that the said electroconductive member is comprised from the same material as the said current collection foil.

  The conductive member is preferably a cut-and-raised part formed by cutting and raising the current collector foil. Thereby, the electrically-conductive member which connects a current collection foil and a 2nd active material layer easily and reliably can be provided.

As preferable embodiment of this invention, it is mentioned that the said electrically-conductive member is comprised from the material different from the said current collection foil.

  Moreover, as preferable embodiment of this invention, it is mentioned that the said electrically-conductive member is comprised so that a contact area with a said 2nd active material layer may become large compared with a contact area with the said current collection foil.

  According to the secondary battery of the present invention, it is possible to achieve an excellent effect of having high output performance while maintaining capacity.

1 is a perspective view showing a secondary battery according to Embodiment 1. FIG. (1) of the secondary battery concerning Embodiment 1 is sectional drawing in the A-A 'line of FIG. 1, (2) is sectional drawing in the B-B' line of FIG. (1) of the secondary battery concerning Embodiment 1 is a partially expanded sectional view of an electrode body, (2) is a partially expanded sectional view of a positive electrode active material layer. (1) of the positive electrode active material layer concerning Embodiment 2 is a schematic diagram which shows a manufacture process, (2) is a partial expanded sectional view. (1) of the positive electrode active material layer concerning Embodiment 3 is a schematic diagram which shows a manufacture process, (2) is a partial expanded sectional view. It is a partial expanded sectional view of the positive electrode active material layer concerning other embodiment. It is a partial expanded sectional view of the positive electrode active material layer concerning other embodiment. It is a partial expanded sectional view of the positive electrode active material layer concerning other embodiment. (1) of the positive electrode active material layer concerning other embodiment is a schematic diagram which shows a manufacture process, (2) is a partially expanded sectional view.

(Embodiment 1)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a secondary battery (lithium ion secondary battery) according to the present embodiment, FIG. 2 (1) is a cross-sectional view taken along line AA ′ of FIG. 2) is a sectional view taken along line BB ′ of FIG.

  The secondary battery 1 of the present invention is mounted on, for example, an electric vehicle. The secondary battery 1 includes a substantially rectangular parallelepiped case 11 and a lid 12 that is disposed in an opening of the case 11 and seals the case 11. As shown in FIG. 2, an electrode body 13 is accommodated in the case 11. An electrolyte solution 14 is injected into the case 11, and the electrode body 13 is immersed in the electrolyte solution 14. The electrode body 13 is formed by winding a laminate of a positive electrode plate and a negative electrode plate with a separator interposed therebetween, and the lamination direction is a horizontal direction in the figure.

As the electrolytic solution 14, lithium hexafluorophosphate is mixed with a commonly used solvent, for example, a mixed solution of cyclic carbonates such as ethylene carbonate and propylene carbonate and chain carbonates such as dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate. An organic electrolytic solution in which (LiPF ₆ ) is dissolved at a molar concentration of about 1 mol per liter can be mentioned.

  The lid portion 12 is provided with a positive electrode terminal 15 and a negative electrode terminal 16. The positive electrode current collector 17 is connected to the positive electrode terminal 15. The negative electrode current collector 18 is connected to the negative electrode terminal 16. The positive electrode current collector 17 and the negative electrode current collector 18 are connected to the positive electrode plate and the negative electrode plate of the electrode body 13, respectively. That is, the positive electrode plate, the positive electrode current collector 17 and the positive electrode terminal 15 are electrically connected to each other. The negative electrode plate, the negative electrode current collector 18 and the negative electrode terminal 16 are electrically connected to each other.

  The electrode body 13 is configured by winding a positive electrode plate and a negative electrode plate provided via a separator. As shown in FIG. 3 (1), the electrode body 13 includes a positive electrode plate 22 and a negative electrode plate 23 provided via a separator 21. The positive electrode plate 22 includes a positive electrode current collector plate 24 and a positive electrode active material layer 25 that is provided on both surfaces of the positive electrode current collector plate 24 and contains a positive electrode active material. The negative electrode plate 23 includes a negative electrode current collector plate 26 and a negative electrode active material layer 27 that is provided on both surfaces of the negative electrode current collector plate 26 and contains a negative electrode active material.

Examples of the negative electrode active material contained in the negative electrode active material layer 27 include active materials usually used for negative electrodes, such as amorphous carbon materials such as graphite, soft carbon, and hard carbon. The graphite may be artificial graphite or natural graphite. In addition, an oxide-based negative electrode material such as Li ₄ Ti ₅ O _12, or a lithium alloy containing Al, Si, Ge, Sn, etc. and having a reversible electrochemical reaction with lithium ions at nearly 0 volts relative to Li or Li ions An alloy negative electrode material that can be used can be used. Furthermore, the negative electrode active material applicable to the present invention is not limited to this, and any material that causes a battery reaction in the negative electrode may be used. For example, other metal lithium, metal oxide, metal sulfide, metal nitride, etc. can be used. As a metal oxide, what has irreversible capacity | capacitance, such as a tin oxide and a silicon oxide, for example may be used.

  Furthermore, the negative electrode active material layer 27 may contain a conductivity improver such as acetylene black and an electrolyte (for example, a lithium salt (supporting electrolyte), an ion conductive polymer, etc.). When an ion conductive polymer is included, a polymerization initiator for polymerizing the polymer may be included.

  The positive electrode active material layer 25 will be described in detail with reference to FIG. The positive electrode active material layer 25 includes a first positive electrode layer (first active material layer) 31 formed on the positive electrode current collector plate 24 and a second positive electrode layer (second active material layer) formed on the first positive electrode layer 31, respectively. ) 32. The first positive electrode layer 31 is configured to have a higher capacity than the second positive electrode layer 32. The second positive electrode layer 32 is configured to have a higher output than the first positive electrode layer 31.

  The first positive electrode layer 31 and the second positive electrode layer 32 are configured such that the first positive electrode layer 31 has a higher capacity than the second positive electrode layer 32, and the second positive electrode layer 32 is higher than the first positive electrode layer 31. Any configuration may be used as long as it is configured to have a high output, but it may be appropriately set in consideration of the output characteristics and capacity characteristics of the active material, the average particle diameter of the active material, and the thickness of each layer.

  The positive electrode active material will be described. In the present embodiment, the second positive electrode layer 32 contains lithium nickelate, and the first positive electrode layer 31 has lithium manganate. By constituting each layer from such an active material, the first positive electrode layer 31 can easily have a higher capacity than the second positive electrode layer 32, and the second positive electrode layer 32 is connected to the first positive electrode layer 31. It can be configured to have a higher output than that.

  The positive electrode active material constituting each layer is not limited to this. For example, in view of output characteristics and capacity characteristics among the positive electrode active materials described below, the second positive electrode layer 32 has a higher output than the first positive electrode layer 31, and the first positive electrode layer 31 is the second positive electrode. Each may be selected so as to have a higher capacity than the layer 32.

Examples of the positive electrode active material include spinel-type metal oxides and metal compounds, and phosphate-type metal oxides. Examples of the layered structure type metal oxide include lithium nickel composite oxide, lithium cobalt composite oxide, and ternary composite oxide (LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ ). The lithium-nickel-based composite oxide, and the like, preferably a lithium nickelate (LiNiO _2). Examples of the lithium cobalt composite oxide, and preferably lithium cobalt oxide (LiCoO _2). Examples of the spinel-type metal oxide include lithium manganese complex oxides such as lithium manganate (LiMn ₂ O ₄ ). Examples of the phosphate metal oxide include lithium iron phosphate (LiFePO ₄ ) and lithium manganese phosphate (LiMnPO ₄ ).

Whether or not these positive electrode active materials have high capacity characteristics can be determined based on, for example, the theoretical capacity of the active material. For example, LiCoO _{2 has} a theoretical capacity of 274 mAh / g, LiNiO _{2 has} a theoretical capacity of 274 mAh / g, LiMn ₂ O _{4 has} a theoretical capacity of 148 mAh / g, and LiFePO _{4 has} a theoretical capacity of 170 mAh / g. Since LiCoO ₂ and LiNiO ₂ have a higher theoretical capacity than LiMn ₂ O ₄ and LiFePO ₄ , it can be determined that they have relatively high capacity characteristics.

  In addition, the active material is selected in view of the output characteristics and capacity characteristics, and the particle size of the active material and the blending of the conductive assistant described below are adjusted so that the second positive electrode layer 32 is more than the first positive electrode layer 31. The first positive electrode layer 31 may have a higher output and a higher capacity than the second positive electrode layer 32.

  The average particle size of the active material contained in the second positive electrode layer 32 is preferably 0.1 to 100 μm, and more preferably 30 μm or less. By being in this range, the total surface area of the active material is increased, thereby improving the reactivity and increasing the output. The second positive electrode layer 32 further includes a conductive additive. Examples of the conductive assistant include acetylene black and ketjen black. In this embodiment, acetylene black is contained. The second positive electrode layer 32 preferably contains 3 to 30% by mass of a conductive additive, more preferably 20% by mass or more. By containing 3 to 30% by mass of the conductive additive, the output characteristics of the second positive electrode layer 32 can be improved. The second positive electrode layer 32 has a thickness of 1 to 100 μm.

  The average particle diameter of the positive electrode active material contained in the first positive electrode layer 31 is preferably 0.1 to 200 μm, more preferably larger than 30 μm. Within this range, it is possible to improve the capacity characteristics. The second positive electrode layer 32 may further contain a conductive additive. In this embodiment, acetylene black is contained as a conductive additive. It is preferable that the conductive assistant is contained in an amount of 0 to 25% by mass, preferably less than 20% by mass. By containing 0 to 25% by mass of the conductive additive, the capacity characteristic of the first positive electrode layer 31 can be improved without reducing the capacity. The first positive electrode layer 31 has a thickness of 5 to 300 μm, preferably thicker than 100 μm.

  The second positive electrode layer 32 has a higher output than the first positive electrode layer 31 in consideration of the output characteristics and capacity characteristics of these active materials, the average particle diameter of the active material, the blending of the conductive auxiliary agent and the layer thickness, In addition, the first positive electrode layer 31 has a higher capacity than the second positive electrode layer 32. That is, the active material of the second positive electrode layer 32 so that the second positive electrode layer 32 has a higher output than the first positive electrode layer 31 and the first positive electrode layer 31 has a higher capacity than the second positive electrode layer 32. The average particle size may be reduced, and the active material of the first positive electrode layer 31 may be increased in average particle size. Further, when the capacity performance is increased so that the second positive electrode layer 32 has a higher output than the first positive electrode layer 31 and the first positive electrode layer 31 has a higher capacity than the second positive electrode layer 32, the thickness is increased. When the thickness is increased and the output performance is improved, the thickness may be decreased.

  Thus, in the present embodiment, the second positive electrode layer 32 has a higher output than the first positive electrode layer 31 in consideration of the output characteristics and capacity characteristics of these active materials, the average particle diameter of the active material, and the layer thickness. In addition, the first positive electrode layer 31 and the second positive electrode layer 32 are configured so that the first positive electrode layer 31 has a higher capacity than the second positive electrode layer 32.

  Even if the same active material is used for the second positive electrode layer 32 and the first positive electrode layer 31, it is possible to reduce the average particle size of the active material of the first positive electrode layer 31, or to increase the conductive auxiliary agent. The output characteristics of the second positive electrode layer 32 can be improved as compared with the first positive electrode layer 31, and the capacity characteristics of the first positive electrode layer 31 can be relatively improved.

  In this embodiment, since the positive electrode active material layer is composed of two positive electrode layers having such different characteristics, the secondary battery can achieve high output and high capacity. That is, if the positive electrode layer is composed of only the first positive electrode layer 31 or the second positive electrode layer 32, either the output characteristic or the capacity characteristic can be satisfied. The second positive electrode layer 32 constitutes the positive electrode layer.

  By the way, if electrons are allowed to reach the positive electrode current collector 24 side from the second positive electrode layer 32 at the time of output, the electrons must pass through the first positive electrode layer 31, and thus the desired output performance cannot be exhibited. Since there is a possibility, it is necessary to prevent this. Therefore, in the present embodiment, the positive electrode current collector plate 24 is composed of two current collector foils 33, and each current collector foil and each second positive electrode layer 32 are electrically connected by a conductive member.

  This will be described in detail below. The positive electrode current collector plate 24 is formed by bonding two current collector foils 33 together. The current collector foil 33 is made of a metal that can be used as a normal wiring such as copper or silver, and is made of aluminum in the present embodiment. Each current collector foil 33 is provided with a positive electrode active material layer 25 on one side thereof. Each current collector foil 33 is provided with a cut-and-raised portion 34 that is partially cut and raised. The tip of the cut-and-raised part 34 extends into the second positive electrode layer 32, and the current collector foil 33 and the second positive electrode layer 32 are electrically connected via the cut-and-raised part 34. .

  In the present embodiment, the output characteristics of the second positive electrode layer 32 can be further improved by providing the cut-and-raised portion 34 in this way. That is, since the cut-and-raised portion 34 functions as a conductive member, the cut-and-raised portion 34 forms a conductive path in which the second positive electrode layer 32 and the current collector foil 33 having high output characteristics are electrically connected. As a result, when high output is required, the electrons of the second positive electrode layer 32 reach the current collector foil 33 via the cut-and-raised portion 34 that is a conductive path, and thus the second positive electrode layer 32 is more responsive. High output can be obtained.

  Thus, in the present embodiment, in order to enhance the output characteristics while maintaining the capacity characteristics, the first positive electrode layer 31 having the high capacity and the second positive electrode layer 32 having the high output are provided, and the second positive electrode layer is provided. 32 and the current collector foil 33 are electrically connected. In this case, if the electrons present in the second positive electrode layer 32 do not pass through the first positive electrode layer 31 and cannot reach the current collector foil 33, the high output characteristics cannot be utilized. The electrons of the two positive electrode layers 32 do not reach the current collector foil 33 via the first positive electrode layer 31 but reach the current collector foil 33 via the cut and raised portion 34. Therefore, electrons move more easily than when passing through the first positive electrode layer 31. As a result, the secondary battery can further exhibit the output performance of the second positive electrode layer 32 and can respond to a high output request.

  In the present embodiment, the two current collector foils 33 are obtained by sticking the cut and raised portions 34 to each other, but the present invention is not limited to this. For example, the cut and raised portions 34 may face each other.

  Note that each of the negative electrode active material layer 27 and the positive electrode active material layer 25 may further contain a binder such as polyvinylidene fluoride.

  In the secondary battery of this embodiment, first, the slurry for forming the first positive electrode layer 31 is prepared for the current collector foil 33 provided with the cut-and-raised part 34, and this is applied and dried. The first positive electrode layer 31 is formed, and then the slurry for forming the second positive electrode layer 32 is prepared, and this is applied and dried to form the second positive electrode layer 32. At the time of drying, heating may be performed, or a pressing process may be performed after drying. In this case, the cut-and-raised part 34 has a certain degree of rigidity, so that even if the slurry is applied, it does not fall down. Then, the two current collector foils 33 on which the first positive electrode layer 31 and the second positive electrode layer 32 are formed are bonded together to form one positive electrode plate 22. Thus, the positive electrode active material layer 25 having the configuration according to the present embodiment can be easily formed.

(Embodiment 2)
In Embodiment 1 described above, the current collector foil 33 and the second positive electrode layer 32 are electrically connected by the cut-and-raised portion 34. However, in this embodiment, as shown in FIG. The difference is that 33A and the second positive electrode layer 32A are electrically connected. In the present embodiment, the current collector foil and the positive electrode active material layer on the separator side are omitted for explanation.

  In this embodiment, after forming the first positive electrode layer 31A and the second positive electrode layer 32A on the current collector foil 33A, the rod-shaped conductive member 35A is inserted from the surface side of the second positive electrode layer 32A. The conductive member 35A is a rod-like member that is longer than the thickness of the first positive electrode layer 31A. For the conductive member 35A, a metal that is normally used as a wiring, such as copper (Cu) or silver (Ag), can be used. The conductive member 35A remains in the positive electrode in contact with the rigid current collector foil 33A.

  In the present embodiment, the conductive member 35A is made of metal, but is not particularly limited as long as it has a low electrical resistance, that is, if it is used as a normal wiring. For example, it may be made of the same metal as the current collector foil 33 or may be made of a different metal.

  In this embodiment formed in this way, the secondary battery also has two positive electrode layers having the first positive electrode layer 31A and the second positive electrode layer 32A, and the second positive electrode layer 32A and the current collector foil. Since 33A is connected by the conductive member 35A, the secondary battery has high output performance while maintaining capacity.

(Embodiment 3)
In Embodiment 2 described above, the conductive path is formed by the conductive member 35A by inserting the rod-shaped conductive member 35A from the surface side of the second positive electrode layer 32A. However, in this embodiment, as shown in FIG. The point which inserts the rod-shaped electrically-conductive member 35B from the foil 33B side, and forms an electroconductive path | route with the electrically-conductive member 35B differs from Embodiment 2. FIG. In the present embodiment, the separator-side current collector foil and the positive electrode active material layer are omitted for the sake of explanation.

  As shown in FIG. 5 (1), in this embodiment, after forming the 1st positive electrode layer 31B and the 2nd positive electrode layer 32B in the current collection foil 33B, it is a rod-shaped electrically-conductive member from the opening 36B provided in the current collection foil 33B. 35B is inserted. The conductive member 35B is the same as the conductive member 35A in the second embodiment. Then, the rod-shaped conductive member 35B is inserted into the opening 36B provided in the current collector foil 33B. In this case, the opening 36B is configured to be slightly smaller in diameter than the conductive member 35B. With this configuration, when the conductive member 35B is inserted into the opening 36B, the conductive member 35B can be connected to the current collector foil 33B, and the second electrode layer 32B and the current collector foil 33B can be connected via the conductive member 35B. And are connected.

  In the present embodiment, the current collector foil 33B is provided with the opening 36B, and the conductive member 35B is inserted through the opening 36B. However, the present invention is not limited to this. The conductive member 35B may be made of a metal harder than the current collector foil 33B, so that the current collector foil 33B can be penetrated by the conductive member 35B and inserted into the positive electrode active material layer.

  Also in this embodiment formed in this way, the secondary battery has positive electrode layers having two different performances of the first positive electrode layer 31B and the second positive electrode layer 32B, and the second positive electrode layer 32B and the current collector foil Since 33B is connected by the conductive member 35B, the secondary battery has high output performance while maintaining capacity.

(Embodiment 4)
In the third embodiment described above, the conductive member 35B has a rod shape, but in the present embodiment, the conductive member 35C is different from the third embodiment in that the conductive member 35C has a nail shape. In the present embodiment, the separator-side current collector foil and the positive electrode active material layer are omitted for the sake of explanation.

  In the present embodiment, the conductive member 35C includes a rod-shaped body portion and a head portion having a larger diameter than the body portion, and the head portion of the conductive member 35C passes through the opening 36C of the current collector foil 33C. When inserted into the layer 31C side, it functions as a stopper. By configuring in this way, the conductive member 35C can more easily come into contact with the current collector foil 33C, and can easily function as a conductive member.

  In this embodiment formed in this way, the secondary battery also has positive electrode layers having two different performances of the first positive electrode layer 31C and the second positive electrode layer 32C, and the second positive electrode layer 32C and the current collector foil Since 33C is connected by the conductive member 35C, the secondary battery has high output performance while maintaining capacity.

(Other embodiments)
The shapes of the cut and raised portion 34 and the conductive members 35A to 35C described above are not limited. For example, in the embodiments shown in FIGS. 7 and 8 described below, the conductive member is configured such that the contact area with the second active material layer is larger than the contact area with the current collector foil. is there.

  As shown in FIG. 7, the conductive member 35 </ b> D may have a plurality of branched ends on the current collecting foil 33 </ b> D. In this case, the output characteristics can be further improved. Furthermore, as shown in FIG. 8, the conductive member 35E may have a pointed end on the base end side with respect to the current collector foil 33E. Thus, it is easier to insert the conductive member 35E by making the tip of the conductive member 35E a pointed end.

  The method for introducing the conductive member into the positive electrode active material layer 25 is not limited to the above-described method. For example, as shown in FIG. 9 (1), the conductive member 35F may be mixed in the slurry in advance and applied, and the conductive member 35F may stand up during drying. In order to erect the conductive member 35F, for example, the conductive member 35F may be erected with a magnet or the like, or may be shaped to elongate as the slurry evaporates during drying.

  Of course, it is also possible to change the nail shape of the conductive member 35C, and to change the number of branches and the branch direction of the conductive members 35D and 35E.

  In the above-described embodiment, the lithium ion battery is used as the secondary battery, but the present invention is not limited to this. Any rocking chair type secondary battery using metal ions as movable ions may be used. Examples of such rocking chair type secondary batteries include sodium ion batteries.

  In the embodiment described above, the conductive members 35A to 35E are provided only on one surface of the current collector foils 33A to 33E. However, the present invention is not limited to this. You may provide so that electroconductive member 35A-35E may exist over both surfaces of current collection foil 33A-33E.

  In the embodiment described above, the first positive electrode layer 31 and the second positive electrode layer 32 are stacked, but the present invention is not limited to this. An adhesion layer may be formed between the first positive electrode layer 31 and the second positive electrode layer 32, or an adhesion layer may be formed between the first positive electrode layer 31 and the current collector foil 33. It is also possible to provide another surface layer on the second positive electrode layer 32.

  In the above-described embodiment, the current collector plate is formed from the two current collector foils 33, but the present invention is not limited to this. For example, the conductive member 35A may be provided from both surfaces after the first positive electrode layer 31A and the second positive electrode layer 32A are formed on both surfaces of the current collector foil 33A.

  In the above-described embodiment, the first positive electrode layer 31 has a higher capacity than the second positive electrode layer 32, and the second positive electrode layer 32 has a higher output than the first positive electrode layer 31. However, it is not limited to this. It is sufficient that the first positive electrode layer 31 and the second positive electrode layer 32 have different characteristics. For example, the first positive electrode layer 31 may have a higher output than the second positive electrode layer 32. Even in this case, the output from the second positive electrode layer 32 can be increased even if the first positive electrode layer 31 is interposed by the conductive member.

DESCRIPTION OF SYMBOLS 11 Case 12 Cover part 13 Electrode body 14 Electrolyte 15 Positive electrode terminal 16 Negative electrode terminal 17 Positive electrode current collector 18 Negative electrode current collector 21 Separator 22 Positive electrode plate 23 Negative electrode plate 24 Positive electrode current collector plate 25 Positive electrode active material layer 26 Negative electrode current collector plate 27 Negative electrode active material layer 31 First positive electrode layer 32 Second positive electrode layer 33 Current collector foil 34 Cut and raised portions 35A to 35E Conductive members 36B and 36C Openings

Claims (6)

A secondary battery comprising a current collector foil and an electrode body having an active material layer provided on the current collector foil, wherein the metal ion of the metal contained in the active material layer is a movable ion,
A first active material layer and the active material layer provided on the collector foil, at least two layers of the second active material layer provided on the other side to the collector foils of the first active material layer Become
The first active material layer has a higher capacity than the second active material layer, the second active material layer has a higher output than the first active material layer,
The second active material layer includes a plurality of conductive members intermittently provided in a plane direction that penetrate the first active material layer and connect the current collector foil and the second active material layer. Secondary battery. The secondary battery according to claim 1 , wherein the active material layer is a positive electrode active material layer containing a positive electrode active material constituting a positive electrode. The conductive member, the secondary battery according to claim 1 or 2, characterized by being composed of the same material and the current collector foil. The secondary battery according to claim 3 , wherein the conductive member is a cut-and-raised portion formed by cutting and raising the current collector foil. The conductive member, the secondary battery according to claim 1 or 2, characterized in that it is composed of a material different from that of the current collector foil. The secondary battery according to claim 5 , wherein the conductive member is configured such that a contact area with the second active material layer is larger than a contact area with the current collector foil.

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