Battery

Abstract

To provide a battery capable of suppressing temperature rise of electrode terminals even when using fast charging for example.SOLUTION: A disclosed battery includes: an electrode body 10; and an exterior body 50 that has an internal area I for storing the electrode body 10. The battery has an electrode terminal 60 that extends from the internal area I of the exterior body 50 to an external area O. The electrode terminal 60 is placed in the internal area I and has an internal current collector 61 connected to an electrode tab 15t of the electrode body 10 and an external current collector 62 placed in the external area O. The width of the internal current collector 61 is larger than the width of the external current collector 62, and the thickness of the internal current collector 61 is larger than the thickness of the external current collector 62. The electrode terminal 60 has a middle part 63 placed between the internal current collector 61 and the external current collector 62 and is positioned in a seal area X of the exterior body 50.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to batteries. [Background technology]

[0002] Batteries are known that include an electrode assembly (an assembly of a positive electrode layer, a separator layer, and a negative electrode layer) and further have electrode terminals connected to the electrode tabs of the electrode assembly. For example, Patent Document 1 discloses an electrode assembly in which an electrode tab and an electrode lead (electrode terminal) are electrically connected, and the end of the electrode lead that is connected to the electrode tab has a rounded structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5550805 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when rapid charging is performed, current may concentrate on the electrode terminals, causing the temperature of the electrode terminals to rise.

[0005] The present disclosure has been made in consideration of the above-described circumstances, and has as its main object to provide a battery that can suppress a temperature rise in the electrode terminals even when rapid charging is performed, for example. [Means for solving the problem]

[0006] The present disclosure provides a battery comprising an electrode body and an exterior body having an internal region for accommodating the electrode body, wherein the battery has electrode terminals arranged to extend from the internal region to an external region of the exterior body, the electrode terminals having an internal current collector arranged in the internal region and connected to an electrode tab of the electrode body, and an external current collector arranged in the external region, and the width of the internal current collector is greater than the width of the external current collector.

[0007] According to the present disclosure, since the width of the internal current collecting portion is larger than the width of the external current collecting portion, even when rapid charging is performed, for example, current concentration at the electrode terminals can be suppressed, and temperature rise at the electrode terminals can be suppressed.

[0008] In the above disclosure, the width of the electrode tab connected to the internal current collector may be greater than the width of the external current collector.

[0009] In the above disclosure, the electrode terminal may have an intermediate portion disposed between the external current collecting portion and the internal current collecting portion and positioned in a sealing region of the exterior body.

[0010] In the above disclosure, the electrode terminal may have an L-shape in plan view.

[0011] In the above disclosure, the battery has at least a first electrode body and a second electrode body as the plurality of electrode bodies, the first electrode body having an electrode tab P, the second electrode body having an electrode tab R having an opposite polarity to the electrode tab P, and the electrode tab P and the electrode tab R may be connected in the internal region.

[0012] In the above disclosure, the first electrode body and the second electrode body may be stacked in the thickness direction with an insulating member interposed therebetween, and the first electrode body and the second electrode body may each have a negative electrode current collector, a first negative electrode layer, a first separate layer, a first positive electrode layer, and a first positive electrode current collector arranged in this order from one surface of the negative electrode current collector, and a second negative electrode layer, a second separate layer, a second positive electrode layer, and a second positive electrode current collector arranged in this order from the other surface of the negative electrode current collector. [Effects of the Invention]

[0013] The battery according to the present disclosure has the advantage of being able to suppress temperature rise in the electrode terminals even when rapid charging is performed, for example. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic plan view illustrating a battery according to the present disclosure. [Figure 2] 1 is a schematic perspective view illustrating a battery and its components according to the present disclosure. FIG. [Figure 3] 1A and 1B are a schematic plan view and a schematic cross-sectional view illustrating an electrode terminal according to the present disclosure. [Figure 4] FIG. 2 is a schematic perspective view illustrating an electrode terminal according to the present disclosure. [Figure 5] FIG. 1 is a schematic cross-sectional view illustrating a battery according to the present disclosure. [Figure 6] 1A and 1B are a schematic plan view and a schematic cross-sectional view illustrating an electrode body according to the present disclosure. [Figure 7] 1 is a schematic cross-sectional view illustrating an electrode body according to the present disclosure. [Figure 8] 1 is a schematic cross-sectional view illustrating an electrode body according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] The battery of the present disclosure will be described in detail below with reference to the drawings. The following drawings are schematic, and the size and shape of each part are appropriately exaggerated for ease of understanding. Hatching indicating the cross section of a component is also omitted as appropriate in each drawing. Furthermore, in this specification, when describing a mode in which another component is disposed relative to a component, the term "above" or "below" is used to refer to both a case in which another component is disposed directly above or below the component so as to be in contact with the component, and a case in which another component is disposed above or below the component via another component, unless otherwise specified.

[0016] Fig. 1 is a schematic plan view illustrating a battery according to the present disclosure. Fig. 2 is a schematic perspective view illustrating a battery according to the present disclosure and its constituent members. Specifically, Fig. 2(a) is a schematic perspective view of the battery shown in Fig. 1, and Fig. 2(b) is a schematic perspective view showing the constituent members of the battery shown in Fig. 2(a).

[0017] As shown in FIGS. 1 and 2, the battery 100 includes a plurality of electrode bodies (a first electrode body 10 and a second electrode body 20) and an exterior body 50 having an interior region I for accommodating these electrode bodies. The first electrode body 10 has a negative electrode tab 11t (electrode tab P) and a positive electrode tab 15t (electrode tab Q). Meanwhile, the second electrode body 20 has a positive electrode tab 25t (electrode tab R) and a negative electrode tab 21t (electrode tab S). The electrode tabs P and R are connected by a connecting member 40 in the interior region I. Also, as shown in FIGS. 1 and 2, one end of the positive electrode terminal 110 is connected to the positive electrode tab 15t (electrode tab Q) in the interior region I, and the other end of the positive electrode terminal 110 is disposed in the exterior region O. Similarly, one end of the negative electrode terminal 120 is connected to the negative electrode tab 21t (electrode tab S) in the internal region I, and the other end of the negative electrode terminal 120 is disposed in the external region O. In this manner, the positive electrode terminal 110 and the negative electrode terminal 120 are each disposed so as to extend from the internal region I of the exterior body 50 to the external region O.

[0018] FIG. 3 is a schematic plan view and a schematic cross-sectional view illustrating an electrode terminal according to the present disclosure. FIG. 3(a) is a schematic plan view illustrating the electrode terminal alone, FIG. 3(b) is a schematic plan view of a battery including the electrode terminal, and FIG. 3(c) is a cross-sectional view taken along line AA of FIG. 3(b). The electrode terminal 60 shown in FIGS. 3(a) to 3(c) has an internal current collecting portion 61, an external current collecting portion 62, and an intermediate portion 63. In the present disclosure, the width W1 of the internal current collecting portion 61 is greater than the width W2 of the external current collecting portion 62.

[0019] According to the present disclosure, because the width of the internal current collecting portion is larger than the width of the external current collecting portion, it is possible to prevent current from concentrating on the electrode terminal, and to prevent a temperature rise in the electrode terminal, even during rapid charging, for example. Furthermore, for example, as shown in FIG. 3 , when the electrode terminal 60 has an intermediate portion 63, a temperature rise in the intermediate portion 63 can cause the resin in the sealing region to melt, making it easier for the sealing performance to deteriorate. In contrast, according to the present disclosure, it is possible to prevent a temperature rise in the electrode terminal, and therefore to prevent a deterioration in the sealing performance.

[0020] 1. Battery configuration As shown in FIG. 1 , the battery according to the present disclosure has electrode terminals (positive electrode terminal 110, negative electrode terminal 120) arranged to extend from an internal region I of the exterior body 50 to an external region O. Also, as shown in FIGS. 3(a) to 3(c), the electrode terminal 60 is arranged in the internal region I of the exterior body 50 and has at least an internal current collecting portion 61 connected to an electrode tab (positive electrode tab 15t) of the electrode body, and an external current collecting portion 62 arranged in the external region O of the exterior body 50. The electrode terminal 60 shown in FIGS. 3(a) to 3(c) is a positive electrode terminal. Here, as shown in FIG. 3(a), the width of the internal current collecting portion 61 is defined as W1, and the width of the external current collecting portion 62 is defined as W2. In the present disclosure, by making W1 > W2, it is possible to prevent current from concentrating on the electrode terminals, and thus to suppress a temperature rise in the electrode terminals, even during rapid charging, for example.

[0021] The value of W1 / W2 is not particularly limited, but may be, for example, 1.2 or more, 1.5 or more, 2.0 or more, or 2.5 or more. If the value of W1 / W2 is too small, current concentration may not be sufficiently suppressed. On the other hand, the value of W1 / W2 is not particularly limited, but may be, for example, 5.0 or less. If the value of W1 / W2 is too large, W2 becomes relatively small, and excessive current concentration may occur at the external current collector. In addition, temperature changes during charging were evaluated by simulation. Specifically, when the positive electrode terminal and the negative electrode terminal have the same shape and W1 and W2 are 25 mm (W1 / W2 = 1), the temperature changes during charging were evaluated by simulation. The difference between the maximum temperature of the electrode terminal and the minimum temperature of the electrode body was 62°C. In contrast, when the positive and negative terminals have the same shape, with W1 being 69 mm and W2 being 25 mm (W1 / W2=2.7), a simulation was conducted to evaluate the temperature change during charging, and the difference between the maximum temperature of the electrode terminal and the minimum temperature of the electrode body was 17° C. In this way, the electrode terminals of the present disclosure can suppress current concentration and temperature rise.

[0022] As shown in FIG. 3(b), the width of the electrode tab (positive electrode tab 15t) connected to the internal current collector 61 is defined as W3. In the present disclosure, the width W3 of the electrode tab is preferably larger than the width W2 of the external current collector 62. This is because the contact area between the internal current collector 61 and the electrode tab (positive electrode tab 15t) is larger, making it less likely for heat to accumulate. As a result, temperature unevenness in the battery is less likely to occur, and battery durability can be improved. The width W3 of the electrode tab may be larger, the same as, or smaller than the width W1 of the internal current collector. The value of W1 / W3 is not particularly limited, but may be, for example, 0.7 to 5, or 0.7 to 2.

[0023] 3(a) to 3(c), the electrode terminal 60 may have an intermediate portion 63 disposed between the internal current collecting portion 61 and the external current collecting portion 62 and located in the seal region X of the exterior body 50. Both surfaces of the intermediate portion 63 are fused to the exterior body 50. A terminal film may be disposed between the intermediate portion 63 and the exterior body 50. The width W4 (not shown) of the intermediate portion 63 is not particularly limited, but is preferably smaller than the width W1 of the internal current collecting portion 61. The preferred range of the value of W1 / W4 is the same as the preferred range of the value of W1 / W2. The width W4 of the intermediate portion 63 may be the same as the width W2 of the external current collecting portion 62.

[0024] The planar shape of the electrode terminal is not particularly limited, but may be, for example, L-shaped. As shown in FIG. 2(b), when the positive electrode terminal 110 and the negative electrode terminal 120 are L-shaped, arranging them in an inverted positional relationship makes it easy to arrange them on the same side of the electrode assembly. This simplifies the battery structure and facilitates improving the volumetric energy density. Furthermore, in the electrode terminals, the internal current collector and the external current collector may be made of the same material or different materials. For example, in the electrode terminal 60 shown in FIG. 3(a), the internal current collector 61 and the external current collector 62 are made of the same material. Meanwhile, in the electrode terminal 60 shown in FIG. 4, the internal current collector 61 and the external current collector 62 are made of different materials. In the electrode terminal 60 shown in FIG. 4, the external current collector 62 and the intermediate portion 63 are made of the same material. In addition, in the present disclosure, the electrode terminal in which the width of the internal current collector is larger than the width of the external current collector may be at least one of the positive electrode terminal and the negative electrode terminal.

[0025] The battery according to the present disclosure includes an electrode assembly and an exterior body having an internal region for housing the electrode assembly. The battery according to the present disclosure may include only one electrode assembly or multiple electrode assemblies.

[0026] For example, as shown in FIGS. 1 and 2, a battery 100 may have a first electrode assembly 10 and a second electrode assembly 20 as electrode assemblies. The first electrode assembly has an electrode tab P and an electrode tab Q having the opposite polarity to that of the electrode tab P. For example, in FIG. 1, the electrode tab P is a negative electrode tab, and the electrode tab Q is a positive electrode tab. Meanwhile, the second electrode assembly has an electrode tab R having the opposite polarity to that of the electrode tab P, and an electrode tab S having the opposite polarity to that of the electrode tab R. For example, in FIG. 1, the electrode tab R is a positive electrode tab, and the electrode tab S is a negative electrode tab. Also, although not shown, when the electrode tab P is a positive electrode tab, the electrode tab Q is a negative electrode tab, the electrode tab R is a negative electrode tab, and the electrode tab S is a positive electrode tab.

[0027] As shown in FIG. 1, the electrode tabs P and R may be connected in the internal region I. In the present disclosure, "connection" refers to at least an electrical connection, and may or may not refer to a physical connection (contact) as long as there is no technical contradiction. As shown in FIGS. 1 and 2, the electrode tabs P and R are arranged on the same side of the electrode assembly and are each in contact with a connecting member 40. This connects the first electrode assembly 10 and the second electrode assembly 20 in series. On the other hand, although not shown, the electrode tabs P and R may be in direct contact without a connecting member.

[0028] As shown in FIG. 2, the first electrode body 10 and the second electrode body 20 are arranged in a thickness direction D T Here, it is assumed that the first current collector located closest to the second electrode body 20 in the first electrode body 10 and the second current collector located closest to the first electrode body 10 in the second electrode body 20 have opposite polarities. For example, it is assumed that the first current collector is a positive electrode current collector and the second current collector is a negative electrode current collector. In this case, in order to connect the first electrode body 10 and the second electrode body 20 in series, it is sufficient to simply bring the first current collector and the second current collector into contact with each other, and there is little need to provide an insulating member 30.

[0029] On the other hand, assume that the first and second current collectors have the same polarity. In this case, in order to connect the first and second electrode bodies 10 and 20 in series, it is preferable to place an insulating member 30 between the first and second electrode bodies 10 and 20 and connect electrode tabs P and R, as shown in Fig. 2. In particular, when both the first and second electrode bodies have a structure as shown in Fig. 7, i.e., a structure including current collectors with the same polarity on both sides, it is preferable to place an insulating member between the first and second electrode bodies because the opposing first and second current collectors have the same polarity.

[0030] 5 is a schematic cross-sectional view illustrating a battery according to the present disclosure, and corresponds to the cross-sectional view taken along line AA in FIG. 1. In FIG. 5, a first electrode body 10 includes a negative electrode current collector 11, a first negative electrode layer 12a, a first separate layer 13a, a first positive electrode layer 14a, and a first positive electrode current collector 15a, which are arranged in this order from one surface of the negative electrode current collector 11, and a second negative electrode layer 12b, a second separate layer 13b, a second positive electrode layer 14b, and a second positive electrode current collector 15b, which are arranged in this order from the other surface of the negative electrode current collector 11. On the other hand, the second electrode body 20 has a negative electrode current collector 21, a first negative electrode layer 22a, a first separate layer 23a, a first positive electrode layer 24a, and a first positive electrode current collector 25a, which are arranged in this order from one surface of the negative electrode current collector 21, and a second negative electrode layer 22b, a second separate layer 23b, a second positive electrode layer 24b, and a second positive electrode current collector 25b, which are arranged in this order from the other surface of the negative electrode current collector 21. Furthermore, an insulating member 30 is arranged between the second positive electrode current collector 15b in the first electrode body 10 and the first positive electrode current collector 25a in the second electrode body 20. Also, as shown in FIG. 5 , the electrode bodies (first electrode body 10, second electrode body 20) may have insulating protective layers 70 on their side surfaces. Providing the insulating protective layers 70 on the side surfaces can prevent short circuits and misalignment of the components constituting the electrode body. Examples of materials for the insulating protective layer include resins, such as urethane acrylate resins, epoxy resins, and olefin resins. The resins may be thermoplastic resins or cured resins (for example, cured products of thermosetting resins or ultraviolet curable resins).

[0031] Examples of materials for the insulating member include resins, and specific examples of resins include polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyimide resins, and polyphenylene sulfide resins (PPS). The insulating member is preferably larger than the first current collector (the current collector in the first electrode body 10 closest to the second electrode body 20) and the second current collector (the current collector in the second electrode body 20 closest to the first electrode body 10) in a planar view. That is, the insulating member preferably encompasses the first current collector and the second current collector in a planar view. This is because the first current collector and the second current collector can be effectively insulated from each other. Furthermore, the insulating member is preferably larger than the largest current collector in the first electrode body (e.g., the negative electrode current collector 11 in FIG. 5) and the largest current collector in the second electrode body (e.g., the negative electrode current collector 21 in FIG. 5) in a planar view. This is because, for example, a short circuit is less likely to occur when the battery is externally pressurized (constrained).

[0032] Furthermore, as shown in FIG. 1, the positive electrode terminal 110 and the negative electrode terminal 120 may be arranged on the same side of the electrode assembly. In this case, the battery structure can be simplified, and it is easier to improve the volumetric energy density. Furthermore, when the positive electrode terminal 110 and the negative electrode terminal 120 are arranged on the same side of the electrode assembly, it is preferable that the positive electrode terminal 110 and the negative electrode terminal 120 are arranged so as not to overlap in a plan view. This is because short circuits are less likely to occur. The positive electrode terminal and the negative electrode terminal may also be arranged on different opposing sides of the electrode assembly.

[0033] When the number of electrode bodies included in the battery of the present disclosure is N, the number N may be 1, 2, or 3 or more. On the other hand, the number N is, for example, 100 or less. When the battery of the present disclosure has a first electrode body to an N-th electrode body (2≦N), the electrode tab T in the N-1th electrode body N-1 and the electrode tab T in the Nth electrode body N The electrode tab T may be connected to the electrode tab T in the internal region of the exterior body. N-1 and electrode tab T Nhave opposite polarities to each other. The first to Nth electrode bodies are preferably made of the same material. The battery according to the present disclosure may also include a plurality of insulating members, which may be disposed between adjacent electrode bodies.

[0034] 2. Electrode body configuration FIG. 6(a) is a schematic plan view illustrating an electrode assembly according to the present disclosure, and FIG. 6(b) is a side view of FIG. 6(a). The electrode assembly E shown in FIGS. 6(a) and 6(b) includes a positive electrode layer 4, a negative electrode layer 2, a separator layer 3 disposed between the positive electrode layer 4 and the negative electrode layer 2, a positive electrode current collector 5 that collects current from the positive electrode layer 4, and a negative electrode current collector 1 that collects current from the negative electrode layer 2. The positive electrode current collector 5 has a positive electrode tab 5t at a position that does not overlap with the positive electrode layer 4 in a planar view. Similarly, the negative electrode current collector 1 has a negative electrode tab 1t at a position that does not overlap with the negative electrode layer 2 in a planar view. The positive electrode current collector 5 and the positive electrode tab 5t may be made of the same material or different materials as long as they are electrically connected. This also applies to the negative electrode current collector 1 and the negative electrode tab 1t.

[0035] Furthermore, as shown in FIG. 6(a), the positive electrode tab 5t and the negative electrode tab 1t may be arranged on different opposing sides (sides s1 and s2) in a plan view (double-sided tab structure). On the other hand, although not shown, the positive electrode tab and the negative electrode tab may be arranged on the same side (one-sided tab structure). The planar shape of the electrode assembly (planar shape excluding the positive electrode tab and the negative electrode tab) is, for example, rectangular. As shown in FIG. 6(a), the planar shape of the electrode assembly E excluding the positive electrode tab 5t and the negative electrode tab 1t is rectangular. The positive electrode tab 5t and the negative electrode tab 1t are arranged to face each other in the longitudinal direction of the electrode assembly E.

[0036] The electrode assembly in the present disclosure may have one, two, or three or more power generation units each having a positive electrode layer, a separator layer, and a negative electrode layer. When the electrode assembly has multiple power generation units, the power generation units may be connected in parallel or in series.

[0037] FIG. 7 is a schematic cross-sectional view illustrating an example of an electrode assembly according to the present disclosure, showing a state in which multiple power generation units are connected in parallel. The electrode assembly E shown in FIG. 7 includes a negative electrode current collector 1, a first negative electrode layer 2a, a first separate layer 3a, a first positive electrode layer 4a, and a first positive electrode current collector 5a, which are arranged in this order from one surface s11 of the negative electrode current collector 1, and a second negative electrode layer 2b, a second separate layer 3b, a second positive electrode layer 4b, and a second positive electrode current collector 5b, which are arranged in this order from the other surface s12 of the negative electrode current collector 1. The first positive electrode current collector 5a and the second positive electrode current collector 5b are connected to form a positive electrode tab 5t. An insulating protective layer 7 is arranged between the second positive electrode current collector 5b and the side surface of the negative electrode (negative electrode current collector 1, first negative electrode layer 2a, and second negative electrode layer 2b) to prevent short circuits.

[0038] The electrode body E shown in FIG. 7 is useful as an electrode body for use in an all-solid-state battery containing an inorganic solid electrolyte, such as an oxide solid electrolyte or a sulfide solid electrolyte. In an all-solid-state battery containing an inorganic solid electrolyte, the electrode body must be pressed with extremely high pressure to form a good ion conduction path. The electrode body E shown in FIG. 7 has the advantage that the configuration of the other layers is symmetrical with respect to the anode current collector 1, making it less susceptible to stress due to differences in the elasticity of the cathode layer and anode layer. Specifically, the electrode body E shown in FIG. 7 has, with respect to the anode current collector 1 as the reference, a first anode layer 2a, a first separate layer 3a, a first cathode layer 4a, and a first cathode current collector 5a arranged in this order on one surface s11, and a second anode layer 2b, a second separate layer 3b, a second cathode layer 4b, and a second cathode current collector 5b arranged in this order on the other surface s12. Since the configuration of the other layers is symmetrical with respect to the negative electrode current collector 1, stress due to differences in the elasticity of the positive electrode layer and the negative electrode layer is unlikely to occur. As a result, breakage of the negative electrode current collector and cracks in the positive electrode layer and the negative electrode layer can be suppressed. In addition, in the present disclosure, a plurality of electrode bodies E shown in FIG. 7 may be used and stacked in the thickness direction to form a single electrode body E'. In this case, the opposing positive electrode current collectors (the first positive electrode current collector 5a in one electrode body E and the second positive electrode current collector 5b in the other electrode body E) may be separate members or the same member (they may share one positive electrode current collector).

[0039] Moreover, the electrode body E shown in FIG. 7 has two positive electrode current collectors for one negative electrode current collector. On the other hand, the electrode assembly according to the present disclosure may have two negative electrode current collectors for one positive electrode current collector. That is, the electrode assembly according to the present disclosure may have a positive electrode current collector, a first positive electrode layer, a first separator layer, a first negative electrode layer, and a first negative electrode current collector, which are arranged in this order from one side of the positive electrode current collector, and a second positive electrode layer, a second separator layer, a second negative electrode layer, and a second negative electrode current collector, which are arranged in this order from the other side of the positive electrode current collector. In this case, the first negative electrode current collector and the second negative electrode current collector may be connected to form a negative electrode tab.

[0040] Fig. 8 is a schematic cross-sectional view illustrating an example of an electrode assembly according to the present disclosure, showing a state in which a plurality of power generation units are connected in series. The electrode assembly E shown in Fig. 8 includes a power generation unit A having a first positive electrode layer 4a, a first separate layer 3a, and a first negative electrode layer 2a, and a power generation unit B having a second positive electrode layer 4b, a second separate layer 3b, and a second negative electrode layer 2b. The first positive electrode layer 4a in power generation unit A is connected to a positive electrode current collector 5, and the second negative electrode layer 2b in power generation unit B is connected to a negative electrode current collector 1. The first negative electrode layer 2a in power generation unit A and the second positive electrode layer 4b in power generation unit B are electrically connected via an intermediate current collector 6.

[0041] The positive electrode layer contains at least a positive electrode active material. The positive electrode layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the positive electrode active material include oxide active materials. Examples of the oxide active material include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of the positive electrode active material include rock salt layer-type active materials such as O2, spinel-type active materials such as LiMn2O4, and olivine-type active materials such as LiFePO4. Sulfur (S) may also be used as the positive electrode active material. The positive electrode active material may be, for example, in the form of particles. Examples of the conductive material include carbon materials. The electrolyte may be a liquid electrolyte or a solid electrolyte. The liquid electrolyte (electrolytic solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Examples of the binder include a rubber-based binder and a fluoride-based binder.

[0042] The negative electrode layer contains at least a negative electrode active material. The negative electrode layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and Li4Ti5O 12Examples of oxide active materials include oxide active materials such as aluminum, stainless steel, nickel, and carbon. The negative electrode active material may be in the form of particles or foil, for example. The conductive material, electrolyte, and binder are the same as those described above. The separator layer contains at least an electrolyte. The electrolyte may be a liquid electrolyte or a solid electrolyte. Examples of materials for the positive electrode current collector include aluminum, stainless steel, nickel, and carbon. Examples of materials for the negative electrode current collector include copper, stainless steel, nickel, and carbon. The positive electrode current collector and the negative electrode current collector may be in the form of foil, for example.

[0043] 3.Battery The battery according to the present disclosure has an exterior body having an internal region for housing an electrode assembly. The exterior body may or may not be flexible. An example of the former is an aluminum laminate film, and an example of the latter is a SUS case. When the exterior body is a laminate film, a seal region may be formed between the internal and external regions of the exterior body, where the inner resin layers of the laminate film are fused together.

[0044] The type of battery in the present disclosure is not particularly limited, but is typically a lithium-ion secondary battery. The use of the battery in the present disclosure is not particularly limited, but examples include power sources for vehicles such as hybrid automobiles, electric automobiles, gasoline-powered automobiles, and diesel-powered automobiles. It is particularly preferred that the battery be used as a driving power source for hybrid automobiles or electric automobiles. The battery in the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0045] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Explanation of symbols]

[0046] 1 … Negative electrode current collector 1t ... negative electrode tab 2...Anode layer 3... Separate layer 4... Positive electrode layer 5... Positive electrode current collector 5t ... Positive electrode tab 10...First electrode body 20…Second electrode body 30...insulating material 40 ... Connecting member 50 ... exterior body 60... Internal current collector 61 ... External current collector 62... Middle section 70...insulating protective layer 100…Battery

Claims

1. A battery comprising an electrode assembly and an exterior body having an internal region for accommodating the electrode assembly, the battery has electrode terminals extending from the interior region to the exterior region of the exterior body; the electrode terminal has an internal current collecting portion disposed in the internal region and connected to an electrode tab of the electrode body, and an external current collecting portion disposed in the external region, The width of the internal current collecting portion is greater than the width of the external current collecting portion, The thickness of the internal current collecting portion is greater than the thickness of the external current collecting portion, the electrode terminal is disposed between the internal current collecting portion and the external current collecting portion and has an intermediate portion located in a sealing region of the exterior body; A battery, wherein the thickness of the internal current collecting portion is greater than the thickness of the entire intermediate portion.

2. In a cross-sectional view perpendicular to the width direction of the internal current collecting portion, the internal current collecting portion has an opposing surface that faces the electrode body, The battery according to claim 1 , wherein the electrode tab is connected to the internal current collector on the opposing surface.

3. A battery as described in claim 1, wherein the intermediate portion has a constant thickness in a direction perpendicular to the width direction.

4. The battery of claim 1 , wherein the sealed area is adjacent to the internal current collector.

5. The battery according to claim 1 , wherein the electrode terminal has an L-shape in a planar view in the thickness direction.

Images