Multifunctional tire and manufacturing method thereof

Abstract

A multifunctional tire includes a tire and a device fixed to the tire. The device includes a substrate and a flat-shaped secondary battery connected to the substrate via a terminal. The secondary battery is embedded with a resin. The secondary battery includes an outer package, and a positive electrode and a negative electrode disposed in the outer package. The negative electrode contains a transition metal oxide as a negative electrode active material. The exterior body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can. The negative electrode can faces the substrate. The secondary battery is disposed further to the outside than the substrate when viewed from the center of rotation of the tire.

Description

Technical Field

[0001] The present invention relates to a multifunctional tire having a device including a flat secondary battery fixed thereto and a method for manufacturing the same. Background Art

[0002] In recent years, a device for monitoring the state of the tire (for example, air pressure) and the like has been installed on the tire. Such a device includes a battery as a power source. Various proposals have been made regarding the installation method of the battery used in such a device.

[0003] Claim 1 of Patent Document 1 (Japanese Patent Publication No. 2011-014452) states: "A method for mounting a flat battery, characterized in that it is a method for mounting a flat battery used in a device having a substrate and mounted on a tire, and the flat battery is arranged on the inner side of the substrate when viewed from the rotation center of the tire."

[0004] Claim 1 of Patent Document 2 (Japanese Patent Publication No. 2014-160660) states, "A method for installing a flat battery, characterized in that it is a method for installing a flat battery used in a device having a substrate and installed on a rotating part, the flat battery is a battery formed by combining a positive electrode can and a negative electrode can so as to face each other, the substrate and the flat battery are faced with each other, and the substrate and the flat battery are connected via terminals, the side of the positive electrode can and the negative electrode can facing each other is set as the side with the smallest deformation caused by swelling when the flat battery expands, and the substrate and the flat battery are buried in a resin."

[0005] Claim 1 of Patent Document 3 (International Publication No. 2017 / 155035) states "A tire pressure detection system is a tire pressure detection system arranged in a tire, comprising an air pressure detection device for detecting the air pressure in the tire and a secondary battery for supplying power to the air pressure detection device, wherein the secondary battery is a lithium secondary battery having a negative electrode and a positive electrode with a lithium alloy as an active material."

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-014452

[0009] Patent Document 2: Japanese Patent Application Publication No. 2014-160660

[0010] Patent Document 3: International Publication No. 2017 / 155035 Summary of the invention

[0011] At present, with the goal of automatic operation, the next generation tire monitoring system (TMS) is being studied, which not only detects the air pressure of the tire, but also senses various information such as acceleration, wear, and temperature. In the next generation tire monitoring system (TMS), the amount of information and the communication frequency have increased significantly, so the capacity will be insufficient if it is a primary battery. In the existing document 1, as a method to prevent the damage of the internal components of the battery caused by impact and vibration, a method of installing the battery on the substrate has been proposed in a device installed on the tire. In the existing document 2, as a method to suppress the detachment of the terminal from the substrate due to the swelling of the battery, the influence of the cracks on the substrate, and the reduction of battery characteristics due to centrifugal force, a method of installing the battery on the substrate has been proposed in a device installed on the rotating part. In the existing document 3, a lithium secondary battery using a lithium alloy as a negative electrode active material has been proposed as a tire pressure gauge. In the past, due to the increase in sensors, the installation position of the secondary battery has become important. In addition, the characteristic changes caused by the charging and discharging of the secondary battery must also be taken into account.

[0012] The multifunctional tire of the present invention does not require battery replacement, is suitable for monitoring the status of the tire, and has high long-term reliability.

[0013] The multifunctional tire of the present invention comprises a tire that rotates around a rotation center and a device fixed to the tire. The device comprises a substrate and a flat secondary battery connected to the substrate via a terminal. The flat secondary battery is embedded with a resin. The flat secondary battery comprises an outer package and a positive electrode and a negative electrode arranged in the outer package. The negative electrode comprises a transition metal oxide as a negative electrode active material. The outer package comprises a positive electrode can with a bottom and a negative electrode can with a bottom. The negative electrode can faces the substrate. The flat secondary battery is configured to be arranged on the outside of the substrate when viewed from the rotation center of the tire.

[0014] In a method for manufacturing a multifunctional tire according to another aspect of the present invention, a device including a substrate and a flat secondary battery is prepared. A tire configured to rotate around a rotation center is prepared. The device is fixed to the tire. The flat secondary battery is connected to the substrate via a terminal, and the flat secondary battery is embedded with a resin. The flat secondary battery includes an outer package and a positive electrode and a negative electrode arranged in the outer package. The negative electrode includes a transition metal oxide as a negative electrode active material. The outer package includes a positive electrode can having a bottom and a negative electrode can having a bottom. The negative electrode can faces the substrate. The device is fixed to the tire in such a manner that the flat secondary battery is arranged on the outside of the substrate when viewed from the rotation center of the tire.

[0015] According to the present invention, a multifunctional tire can be obtained in which a device using a flat secondary battery is fixed, the device being suitable for monitoring the state of the tire and having high long-term reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram schematically showing the device and tire according to the first embodiment.

[0017] Figure 2A This is a plan view schematically showing an example of a flat secondary battery used in the device of Embodiment 1.

[0018] Figure 2B Schematically represents the Figure 2A A cross section of the flat secondary battery taken along line IIB-IIB.

[0019] Figure 3 The configuration and arrangement of the device according to the first embodiment are schematically shown. DETAILED DESCRIPTION

[0020] Hereinafter, the embodiments of the present invention are described by way of example, but the present invention is not limited to the examples described below. In the following description, sometimes specific numerical values ​​and materials are illustrated, but as long as the effect of the present invention can be obtained, other numerical values ​​and materials can also be applied. In the following description, when the examples of constituent elements and the examples of methods are listed, as long as there is no special record, only one of the examples listed can be used, or a plurality of the examples listed can be used in combination.

[0021] (Device installed on tire)

[0022] The device of this embodiment is a device mounted on a tire. Hereinafter, the device is sometimes referred to as "device (D)". Device (D) includes a substrate and a flat secondary battery connected to the substrate via a terminal, and the flat secondary battery is embedded in a resin. The flat secondary battery includes an outer packaging body and a positive electrode and a negative electrode arranged in the outer packaging body. The negative electrode includes a transition metal oxide as a negative electrode active material. The outer packaging body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can. The negative electrode can faces the substrate. The flat secondary battery is arranged on the outside of the substrate when viewed from the rotation center of the tire.

[0023] In the next generation tire monitoring system (TMS), the primary battery needs to be converted to a secondary battery because of insufficient capacity. In addition, the device installed on the tire in the next generation tire monitoring system (TMS) is different from the previous installation on the valve. It is directly installed on the inner surface of the tread of the tire that contacts the ground, the inner surface of the side wall surface, and the wheel hub. Therefore, it is subject to impact and vibration in addition to centrifugal force. Due to the greater physical external force than before, it is easy to cause problems such as the connection between the terminal of the secondary battery and the substrate. In addition, it is also easy to cause the characteristics to be reduced due to the damage of the components inside the battery. In addition, the device is easily affected by heat such as the road surface temperature of the tire and the friction during driving, and is more susceptible to the impact of temperature changes than before. For example, drastic temperature changes occur in the range of -40°C on the low temperature side and 105°C, 125°C, and 150°C on the high temperature side. In particular, it is easy to be exposed to high temperatures due to temperature rise, and the battery is easy to deteriorate. In the next generation tire monitoring system (TMS), the influence of physical external forces and high temperatures such as high temperatures has become greater than before.

[0024] In secondary batteries using lithium alloys as negative electrode active materials, the negative electrode active materials are pulverized due to the expansion and contraction of the negative electrode active materials during charge and discharge, and the detachment of the negative electrode active materials from the negative electrode and the reduction of current collection reduce the discharge capacity. If a device including a secondary battery using lithium alloys as negative electrode active materials is installed on a tire, physical external forces such as impact and vibration and temperature change impact from low temperature to high temperature are applied in combination on the basis of centrifugal force while repeatedly performing charge and discharge cycles. As a result, the pulverization of the lithium alloy of the negative electrode active material is rapidly promoted, and the capacity of the secondary battery is rapidly reduced. Therefore, due to the deterioration of the secondary battery, it is impossible to maintain the performance required of the device itself for a long time, and it must be replaced regularly like a primary battery.

[0025] The device (D) uses a secondary battery formed by a negative electrode containing a transition metal oxide as a negative electrode active material of the present invention. Since the transition metal oxide has small expansion and contraction during the charge and discharge cycle, it does not undergo pulverization, and there is no detachment of the active material or reduction in current collection, and can maintain excellent charge and discharge cycle performance. In addition, it is not easily affected by physical external forces and temperature change shocks. Therefore, the secondary battery of the present invention does not require battery replacement and can ensure sufficient battery capacity for a long time. In addition, in the device (D), since the secondary battery is embedded in a resin, physical external forces do not directly affect the battery, and the occurrence of undesirable conditions such as detachment of the connection between the battery terminal and the substrate and damage to the internal structure of the battery can be suppressed. In addition, in the device (D), the negative electrode can is arranged closer to the rotation center side of the tire than the positive electrode can. The influence of the temperature rise accompanying the tire is reduced on the negative electrode side. The load applied to the actual battery varies greatly due to the combination of the ambient temperature and the charging state, and the degradation of the battery during charging is accelerated with the temperature rise. In the design of the battery, the negative electrode capacity is limited to be smaller than the positive electrode capacity, and the transition metal oxide of the negative electrode is more susceptible to the negative electrode than the positive electrode. Therefore, the deterioration effect caused by the reaction between the negative electrode and the electrolyte in the high-temperature charging state becomes greater. By configuring the negative electrode can of the present invention, the influence of the temperature rise of the tire can be reduced and the degradation of the battery can be suppressed. As described above, according to the device (D), even in a harsh environment installed in the tire, it is possible to maintain a sufficient battery capacity. In addition, since the volume change of the negative electrode during charging and discharging is greater than that of the positive electrode, the negative electrode is weaker in terms of strength, and the physical damage of the negative electrode as an effect of the battery configuration is also reduced. Therefore, the device (D) does not require battery replacement and has high reliability without maintenance for a long time. That is, the device (D) is suitable for monitoring the state of the tire and has high reliability. The multifunctional tire includes a tire and a device (D) fixed to the tire, and has other functions such as being able to monitor the state of the tire from the outside in addition to the original functions of the tire.

[0026] The device (D) can be used to monitor the pressure, temperature, acceleration, etc. in the tire. That is, the device (D) can be used in a tire monitoring system (TMS). In addition, according to these purposes, the device (D) includes necessary electronic components such as sensors corresponding to the acquired information.

[0027] In the device (D), the flat secondary battery is arranged on the outside of the substrate when viewed from the rotation center of the tire. Therefore, in the device (D), at least a part or all of the electronic components can be arranged on the inside (the side where the flat secondary battery is not arranged) of the substrate when viewed from the rotation center of the tire. Therefore, the device (D) can be miniaturized and lightweight. In the case where a device for monitoring the state of a tire is installed on a tire, miniaturization and lightweighting of the device are particularly important from the perspectives of tire balance, fuel consumption rate, etc. In addition, according to the above configuration, the influence of physical external forces such as centrifugal force, impact, vibration, and thermal shock changes from the tire on electronic components other than the secondary battery can be reduced. Of course, at least a part or all of the electronic components can also be arranged on the same side as the flat secondary battery. By utilizing the configuration of the present invention, it is also possible to simultaneously improve the tolerance of electronic components other than the flat secondary battery in the harsh environment of being installed on the tire.

[0028] The device (D) is fixed to the inner surface of the tire (the surface that is not exposed to the outside air when in use). For example, the device (D) can be fixed to the tread portion of the tire that contacts the ground or the sidewall portion of the side. The method of fixing the device (D) to the tire is not limited. The device (D) can be installed in a clamp that can fix the device on the inner surface of the tire, or directly fixed to the tire using an adhesive. Alternatively, it can be fixed to the inner surface of the tire and the outer surface of the wheel hub.

[0029] Transition metal oxides are oxides containing transition metals. Transition metal oxides may be composite oxides containing lithium and transition metals, for example, composite oxides containing lithium and titanium. Such composite oxides (e.g., lithium titanate) have excellent resistance to reduction and decomposition of electrolytes and electrolytes in the range of 1.0 to 2.0 V relative to lithium, compared with transition oxides such as alloys, other silicon systems, and tin systems with a potential of less than 1 V, so the degradation of electrolytes such as non-aqueous electrolytes and solid electrolytes caused by temperature rise is small. And because the expansion and contraction during charging and discharging are small and there is basically no degradation of the negative electrode itself, it is particularly preferred. Examples of such composite oxides are described later.

[0030] (tire)

[0031] The tire of the present embodiment is a tire equipped with the device (D) of the present embodiment. The tire is not particularly limited and may be a known tire. The tire may be a tire used in various transport machines or may be a tire other than these. Examples of transport machines include motor vehicles (four-wheeled motor vehicles, three-wheeled motor vehicles, two-wheeled motor vehicles, and other motor vehicles) and the like.

[0032] (Method of installing a flat secondary battery)

[0033] The installation method of the present embodiment is an installation method for a flat secondary battery used in a device that includes a substrate and is installed on a tire. Hereinafter, this installation method is sometimes referred to as "installation method (M)". The multifunctional tire includes a tire and a device (D) fixed to the tire. The device (D) is prepared, the tire is prepared, and the device (D) is fixed to the tire, thereby manufacturing the multifunctional tire. The flat secondary battery is connected to the above-mentioned substrate via a terminal, and the flat secondary battery is embedded by a resin. The flat secondary battery includes an outer packaging body and a positive electrode and a negative electrode arranged in the outer packaging body. The negative electrode includes a transition metal oxide as a negative electrode active material. The outer packaging body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can. The above-mentioned negative electrode can faces the substrate. The positive electrode can is located on the opposite side of the substrate relative to the negative electrode can. The flat secondary battery is arranged on the outside of the substrate when viewed from the rotation center of the tire. That is, the flat secondary battery is located away from the rotation center relative to the substrate.

[0034] The mounting method (M) can be performed by mounting the flat secondary battery as described for the device (D). Since the matters described for the device (D) can be applied to the mounting method (M), repeated descriptions may be omitted. According to the mounting method (M), the effects described for the device (D) can be obtained.

[0035] As described above, the transition metal oxide used as the negative electrode active material may be a composite oxide containing lithium and titanium.

[0036] The following is a description of the configuration and components of the device (D) of this embodiment. However, the configuration and components of the device (D) are not limited to the following description. As described above, the following description can also be applied to the mounting method (M).

[0037] (Flat secondary battery)

[0038] Examples of flat secondary batteries are batteries whose plane shape is circular, including coin-shaped and button-shaped secondary batteries. Flat secondary batteries can use lithium ion secondary batteries containing transition metal oxides as negative electrode active materials. The lithium ion secondary battery is not particularly limited, and a known lithium ion secondary battery can be used. The manufacturing method of the flat secondary battery is not limited, and it can be manufactured using a known method.

[0039] The flat secondary battery includes a positive electrode, a negative electrode, an electrolyte, and an outer package. A separator may be disposed between the positive electrode and the negative electrode. Matters other than those required in the embodiment of the present invention are not particularly limited, and known structures and components may be applied.

[0040] The positive electrode includes a positive electrode mixture, and the positive electrode mixture includes a positive electrode active material. The positive electrode active material can use a material that can reversibly absorb and release lithium ions. Examples of positive electrode active materials include composite oxides containing at least one selected from Ni, Co, Mn, Fe and Al and lithium, such as lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, ternary nickel-manganese-cobalt lithium composite oxide, olivine-type lithium iron phosphate, and lithium cobalt phosphate. The positive electrode mixture can include various additives (binders, conductive materials, etc.) on the basis of the positive electrode active material. Alternatively, the positive electrode mixture consisting only of the positive electrode active material without various additives can be sintered and used as the positive electrode. The negative electrode includes a negative electrode mixture, and the negative electrode mixture includes a negative electrode active material. The negative electrode mixture can include various additives (binders, conductive materials, etc.) on the basis of the negative electrode active material. Alternatively, the negative electrode mixture consisting only of the negative electrode active material without various additives can be sintered and used as the negative electrode. The positive electrode and the negative electrode can be formed into a cylindrical shape, respectively. In addition, conventional primary batteries using lithium metal are also affected by uneven distribution of the electrolyte due to centrifugal force. However, if electrodes in which the positive and negative electrodes are formed into cylindrical shapes are used, this influence is basically eliminated.

[0041] Oxides (e.g., transition metal oxides) that can reversibly absorb and release lithium ions can be used as negative electrode active materials. Transition metal oxides contain at least transition metals and may also contain elements other than transition metals. Examples of oxides (e.g., transition metal oxides) of negative electrode active materials are SiO, SnO, CuO, Cu2O, Fe2O3, Fe3O4, ZnO, PbO, MoO, MoO2, TiO2, Nb2O5, TiNb2O7, Li4Ti5O 12 、Li2TiO3、Li 1.4 Al 0.4 Ti 1.6 (PO4)3, etc. As the element that can be added to the above oxide, there can be mentioned at least one selected from Fe, Mn, Ni, Co, Sc, Y, Cu, Zn, Al, Cr, Pb, Sb, Mg and B. MoO, MoO2, TiO2, Nb2O5, TiNb2O7, Li4Ti5O, which have a potential of 1V or more relative to metallic lithium and are not easily reductively decomposed by non-aqueous electrolytes or solid electrolytes, are preferred. 12 、Li2TiO3、Li 1.4 Al 0.4 Ti 1.6 (PO4)3. In addition, it can also be a composite oxide containing lithium and titanium that has very small expansion and contraction (volume change) during charge and discharge. Examples of such composite oxides include lithium titanate, specifically, Li4Ti5O 12A portion of Ti may be replaced by other elements, and the content of the other elements is smaller than the content of Ti. Examples of other elements include at least one selected from Fe, Mn, Ni, Co, Sc, Y, Cu, Zn, Al, Cr, Pb, Sb, Mg and B.

[0042] The electrolyte may be a non-aqueous electrolyte in which a lithium salt is dissolved in a non-aqueous solvent, or an inorganic solid electrolyte such as a sulfide-based, oxide-based, chloride-based, etc. containing lithium, a solid electrolyte such as a polymer solid electrolyte containing a lithium salt, or an ionic liquid. If a solid electrolyte is used, the influence of uneven distribution of the electrolyte due to centrifugal force can be completely ignored, so it is more preferred. The separator may be a non-woven fabric or a microporous membrane made of an insulating material (such as an insulating resin) such as an olefin-based material such as polypropylene and polyethylene, an engineering plastic material such as polyphenylene sulfide and polyetheretherketone, a cellulose-based material, an inorganic material such as glass, or the like.

[0043] The outer packaging body includes a positive electrode tank with a bottom cylindrical shape and a negative electrode tank with a bottom cylindrical shape. The positive electrode tank and the negative electrode tank are arranged to face each other with a gasket in between, forming a coin-shaped or button-shaped outer packaging body. The positive electrode is arranged on the positive electrode tank side, and the negative electrode is arranged on the negative electrode tank side. The materials of the positive electrode tank, the negative electrode tank and the gasket are not particularly limited, and the known materials used by each can be used. The material of the gasket is preferably able to withstand the temperature of thermal curing during resin embedding. For example, engineering plastics such as polyphenylene sulfide (PPS), polyetheretherketone (PEEK), copolymers of tetrafluoroethylene and perfluoroether (PFA), olefin-based materials, etc. In addition, materials with glass and fillers added to the above materials can also be used.

[0044] The material of the positive electrode tank and the material of the negative electrode tank can be a metal clad material such as iron, stainless steel, aluminum and iron, aluminum and stainless steel, iron and copper, stainless steel and copper, or iron, stainless steel, or metal clad with nickel plating on the surface. In addition, the material of the positive electrode tank and the material of the negative electrode tank can also be independently selected from at least one of austenitic stainless steel, 2-phase stainless steel composed of austenitic stainless steel and ferritic stainless steel, and nickel alloy. The material of the positive electrode tank and the material of the negative electrode tank can be the same or different from each other. These materials are weaker in magnetism than other materials. In the case of charging a secondary battery by wireless power supply using electromagnetic induction such as magnetic field resonance and magnetic field coupling, by using an outer packaging tank (positive electrode tank and negative electrode tank) made of a material with weak magnetism, it is possible to suppress the outer packaging tank from being heated by the supplied magnetic flux due to wireless power supply. As a result, it is possible to suppress the deterioration of the flat secondary battery caused by the temperature rise due to heating.

[0045] The positive electrode can can function as a positive electrode terminal, and the negative electrode can can function as a negative electrode terminal. A conductive layer (carbon layer, current collector, etc.) can be disposed between the positive electrode mixture and the positive electrode can. A conductive layer (carbon layer, current collector, etc.) can be disposed between the negative electrode mixture and the negative electrode can.

[0046] The negative electrode can is disposed to face the substrate. The bottom surface of the negative electrode can is usually disposed substantially parallel to the substrate, but may be inclined to a certain degree (eg, an angle of 30° or less) relative to the substantially parallel state to the substrate.

[0047] (Substrate)

[0048] The substrate is not particularly limited as long as it is a substrate that can stably hold a flat secondary battery. A known substrate can be used as the substrate. Examples of substrates include known substrates used as printed wiring boards. Examples of materials for the substrate include paper, resins such as epoxy, glass, and ceramics. The substrate can be formed using at least one of these materials. The substrate includes electrical wiring.

[0049] The size of the substrate is not particularly limited, and is generally larger than the size of the planar shape of the flat secondary battery. A smaller size is preferred in view of the effect on the balance of the tire. For example, when the planar shape of the substrate is a rectangle, the length of its side may be in the range of 1 to 2 times (e.g., 1.1 to 1.8 times) the diameter D of the circular planar shape of the flat secondary battery. The area of ​​the planar shape of the substrate may be in the range of 1 to 2 times (e.g., 1.1 to 1.8 times) the area of ​​the planar shape of the flat secondary battery.

[0050] (resin)

[0051] The resin for embedding the flat secondary battery is not particularly limited. In Patent Document 2, a resin that ensures water resistance and moisture resistance is used, and in the present invention, a material with high shock absorption such as vibration is preferably used. The resin may also be a resin used for sealing electronic components. Examples of resins include urethane resins, epoxy resins, and silicone resins. The resin may also contain fillers such as inorganic particles.

[0052] The resin is configured to cover at least the substrate and the flat secondary battery with the terminal. According to this configuration, it is possible to suppress the situation where the flat secondary battery terminal is disconnected from the substrate. In addition, it is possible to suppress the situation where the physical external force directly affects the battery. In the case where the device (D) includes a shell surrounding the flat secondary battery, the interior of the shell can be filled with resin.

[0053] (Electronic components other than flat secondary batteries, etc.)

[0054] The device (D) may include sensors, power receiving units, power generating elements, transmission units, processing units, etc. as electronic components other than the flat secondary battery, depending on the purpose. Electric power is supplied from the flat secondary battery to these electronic components as needed.

[0055] Examples of sensors include pressure sensors, acceleration sensors, and temperature sensors. The transmitter is a component used to transmit various information (such as information obtained by the sensor) to the receiver, and includes an antenna. The processor performs various processing and control. For example, the processor transmits information output from the sensor via an antenna. The processor may use an integrated circuit (IC).

[0056] The information transmitted from the transmission unit is received by, for example, a reception unit disposed on the vehicle body. The received information is processed by, for example, a control device disposed on the vehicle body, and then used.

[0057] The flat secondary battery of the device (D) can be charged by wireless power supply. For example, the flat secondary battery of the device (D) can be charged by wireless power supply using electromagnetic induction such as magnetic field resonance and magnetic field coupling. In this case, the power transmission unit (coil, antenna, etc.) for wireless power supply is arranged on the vehicle body, etc., and the device (D) includes a power receiving unit. The power receiving unit is a part that generates power by electromagnetic induction. Examples of the power receiving unit include coils and antennas. The flat secondary battery of the device (D) can also be charged by a power generating element. Examples of power generating elements include piezoelectric elements that generate power by vibration, Peltier elements that generate power by temperature difference, etc. The charging of the secondary battery may be roughly continuous, or it may be charged when a certain amount of capacity is discharged (charge and discharge cycle). For example, it may be charged when 1% of the capacity is discharged, charged when 50% of the capacity is discharged, or charged when 100% of the capacity is discharged. In particular, when the battery is close to full charge, the reaction between the negative electrode and the electrolyte is more advanced at a higher temperature such as 85°C, 105°C, or 125°C, and thus the capacity is reduced due to an increase in the resistance of the battery. In the negative electrode of Patent Document 3 using a lithium alloy as the active material, the expansion and contraction of the active material promotes pulverization due to repeated charge and discharge cycles, thereby increasing the reaction area, and thus further promoting charging degradation at high temperatures. In addition, pulverization is also caused by physical forces from the outside of the tire, and thus the degradation of the battery characteristics is further accelerated due to the reduction in capacity and the reduction in current collection due to the detachment of the active material.

[0058] (terminal)

[0059] One end of the terminal (lead terminal) can be connected to the positive electrode can and the negative electrode can, respectively. The other end of the terminal can be connected to the wiring of the substrate. The shape of the terminal is not particularly limited as long as electrical connection can be achieved. For example, a terminal made of metal such as stainless steel can be used. In the case of wireless power supply using electromagnetic induction such as magnetic field resonance and magnetic field coupling, materials with weak magnetism are particularly preferred. The materials can each independently be at least one selected from austenitic stainless steel, two-phase stainless steel consisting of austenitic stainless steel and ferritic stainless steel, and nickel alloy. The materials of the positive electrode can and the negative electrode can can be the same or different from each other. The terminal is connected to the outer packaging can of the flat secondary battery, for example, by resistance welding or laser welding. In addition, regarding the electrical connection between the substrate and the terminal, for example, the terminal is welded to the substrate.

[0060] (case)

[0061] The device (D) may include a housing surrounding the flat secondary battery. The housing may surround the entire device (D). However, in the case of charging the flat secondary battery by wireless power supply, the housing is selected so as to enable wireless power supply. The housing is not particularly limited, and a housing made of metal and / or resin may be used.

[0062] Hereinafter, examples of embodiments of the present invention are specifically described with reference to the accompanying drawings. The embodiments described below can be changed based on the above description. In addition, the matters described below can also be applied to the above embodiments. In addition, in the embodiments described below, matters that are not essential to the invention of the present invention can be omitted.

[0063] (Implementation method 1)

[0064] In the first embodiment, examples of the device (D), the tire on which the device (D) is mounted, and the mounting method (M) are described. Figure 1 2 is a cross-sectional view of a portion of the tire 10 to which the device 100 is mounted. The multifunctional tire 50 includes the tire 10 and the device 100 fixed to the tire 10.

[0065] Figure 1 The cross-sectional view shows a plane including the rotation center C of the tire 10 ( Figure 1 The cross section of a portion of the tire 10 in the plane shown in FIG. 1 is a rubber tire used in automobiles and the like, and is configured to rotate around a rotation center C. The device 100 is the above-mentioned device (D). The device 100 is mounted on the inner surface 10b of the tread portion of the tire 10 on the side (inner surface) opposite to the contact surface (outer side) 10a. The device 100 is fixed to the inner surface 10b by an adhesive.

[0066] The device 100 includes a flat secondary battery 200. The top view of the secondary battery 200 is shown in FIG. Figure 2A In Figure 2A The cross-sectional view at the line IIB-IIB is shown in Figure 2B In. Figure 2A and Figure 2B As shown, the secondary battery 200 has a coin-shaped (low cylindrical) shape.

[0067] The secondary battery 200 includes an outer package 210, a positive electrode 221, a negative electrode 222, a separator 223, and a non-aqueous electrolyte. The outer package 210 includes a bottomed cylindrical positive electrode can 211, a bottomed cylindrical negative electrode can 212, and a gasket 213. The positive electrode can 211 and the negative electrode can 212 face each other with the gasket interposed therebetween, thereby forming a coin-shaped outer package 210.

[0068] The positive electrode can 211 includes a circular bottom surface 211 b and a cylindrical portion rising from the outer edge of the bottom surface 211 b. The negative electrode can 212 includes a circular bottom surface 212 b and a cylindrical portion rising from the outer edge of the bottom surface 212 b. Figure 2B In the example shown, at least a part of the cylindrical portion of the negative electrode can 212 is arranged inside the cylindrical portion of the positive electrode can 211. The positive electrode can 211 and the negative electrode can 212 are made of austenitic stainless steel SUS316L.

[0069] The positive electrode 221 and the negative electrode 222 are formed by forming the positive electrode mixture and the negative electrode mixture into a cylindrical shape, respectively. Thereafter, drying is performed by heating at a temperature of 100°C or higher. The positive electrode mixture contains lithium cobalt oxide as an active material, acetylene black as a conductive agent, and a fluorine-based resin as a binder. The negative electrode mixture contains lithium titanate as an active material, acetylene black as a conductive agent, and a rubber-based material as a binder. The battery voltage is 2.6V in the charged state. The potential of the positive electrode at room temperature is about 4.0V relative to metallic lithium. The potential of the negative electrode at room temperature is about 1.4V relative to metallic lithium. The positive electrode 221 is arranged on the positive electrode can 211 side and abuts against the positive electrode can 211 facing each other. The negative electrode 222 is arranged on the negative electrode can 212 side and abuts against the negative electrode can 212 facing each other. A separator 223 is arranged between the positive electrode 221 and the negative electrode 222. The separator 223 , the positive electrode 221 , and the negative electrode 222 are filled with a non-aqueous electrolyte.

[0070] The structure of the device 100 is schematically shown in Figure 3 It should be noted that Figure 3 In order to make the drawings easier to see, some hatching is omitted. Figure 3The device 100 includes a substrate 110 , a resin 130 , a case 140 , and a flat secondary battery 200 connected to the substrate 110 via terminals (lead terminals) 121 and 122 .

[0071] The secondary battery 200 is welded to the electrical wiring of the substrate 110 by using the terminal 121 connected to the positive electrode can 211 and the terminal 122 connected to the negative electrode can 212. The resin 130 is arranged so as to surround the secondary battery 200 and the terminals 121 and 122. The resin 130 is arranged between the substrate 110 and the secondary battery 200, and the secondary battery 200 is embedded in the resin 130, thereby being fixed to the substrate 110. The housing 140 surrounds the secondary battery 200 and functions as an outer package of the device 100.

[0072] When viewed from the rotation center C of the tire 10, the secondary battery 200 is arranged on the outer side than the substrate 110. That is, the secondary battery 200 is arranged away from the rotation center C of the tire 10 relative to the substrate 110. The secondary battery 200 is arranged so that the negative electrode can 212 faces the substrate 110. The positive electrode can 211 is located on the side opposite to the substrate 110 relative to the negative electrode can 212. That is, the bottom surface of the negative electrode can 212 is arranged to be closer to the rotation center side, that is, the rotation center C, than the bottom surface of the positive electrode can 211. That is, the negative electrode is arranged to be closer to the rotation center side, that is, the rotation center C, than the positive electrode. According to the configuration of Embodiment 1, the above-mentioned effects can be obtained.

[0073] In addition to being subjected to centrifugal force, the device 100 is also strongly affected by vibration, impact, and temperature changes from low to high temperatures from the road surface. In the case where the secondary battery 200 with terminals is not buried in the resin 130, the connection between the terminals 121 and 122 of the secondary battery 200 and the substrate is easily detached due to vibration and impact from the road surface. In addition, when the secondary battery 200 is configured so that the positive electrode can 211 faces the substrate 110, the resistance increase caused by the reaction between the negative electrode and the electrolyte (when charging at high temperature) that is easily affected by the temperature rise becomes larger, and the deterioration of the secondary battery is accelerated. Moreover, the negative electrode is easily affected by physical forces such as impact from the outside, and the deterioration of the secondary battery is accelerated. This effect is significant when a lithium alloy negative electrode is used as the negative electrode active material. In addition, in the previous example, the suppression of detachment from the substrate caused by the swelling of the battery at high temperature was dealt with by the configuration of the side of the battery swelling and the resin embedding, but the problem of charging and discharging from the secondary battery was not considered. On the other hand, the device 100 of the present invention can suppress the occurrence of these problems.

[0074] (Note)

[0075] Based on the above description, the following technology is disclosed.

[0076] (Technique 1)

[0077] A multifunctional tire comprises a tire rotating around a rotation center and a device fixed to the tire.

[0078] The device includes a substrate and a flat secondary battery connected to the substrate via a terminal, wherein the flat secondary battery is embedded in a resin.

[0079] The flat secondary battery includes an outer package, and a positive electrode and a negative electrode disposed in the outer package.

[0080] The negative electrode comprises a transition metal oxide as a negative electrode active material.

[0081] The outer packaging body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can.

[0082] The negative electrode can faces the substrate.

[0083] The flat secondary battery is configured to be arranged outside the substrate when viewed from the rotation center of the tire.

[0084] (Technique 2)

[0085] In the multifunctional tire according to the first aspect, the transition metal oxide is a composite oxide containing lithium and titanium.

[0086] (Technique 3)

[0087] In the multifunctional tire according to the technique 1 or 2, the positive electrode can is located on the side opposite to the substrate with respect to the negative electrode can.

[0088] (Technique 4)

[0089] A manufacturing method is a manufacturing method of a multifunctional tire, the manufacturing method comprising:

[0090] a step of preparing a device including a substrate and a flat secondary battery;

[0091] The step of preparing a tire configured to rotate about a rotation center; and

[0092] The step of fixing the device to the tire,

[0093] The flat secondary battery is connected to the substrate via a terminal, and the flat secondary battery is embedded in a resin.

[0094] The flat secondary battery comprises an outer package and a positive electrode and a negative electrode disposed in the outer package.

[0095] The negative electrode comprises a transition metal oxide as a negative electrode active material.

[0096] The outer packaging body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can.

[0097] The negative electrode can faces the substrate.

[0098] The step of fixing the device to the tire includes fixing the device to the tire so that the flat secondary battery is arranged outside the substrate when viewed from the rotation center of the tire.

[0099] (Technique 5)

[0100] According to the production method described in Technology 4, the transition metal oxide is a composite oxide containing lithium and titanium.

[0101] (Technique 6)

[0102] According to the manufacturing method described in technology 4 or 5, the positive electrode can is located on the side opposite to the substrate with respect to the negative electrode can.

[0103] Industrial Applicability

[0104] The present invention can be applied to a multifunctional tire including a tire and a device mounted on the tire, and a method for manufacturing the same.

[0105] Description of Reference Numerals

[0106] 10 tire, 10a ground contact surface, 50 multifunctional tire, 100 device, 110 substrate, 121, 122 terminals, 140 housing, 200 flat secondary battery, 210 outer package, 211 positive electrode can, 212 negative electrode can, 213 gasket, 221 positive electrode, 222 negative electrode, 223 spacer, C rotation center.

Claims

1. A multifunctional tire, comprising a tire rotating around a rotation center, and a device fixed to the tire, The device includes a substrate and a flat secondary battery connected to the substrate via a terminal, wherein the flat secondary battery is embedded in a resin. The flat secondary battery includes an outer package, and a positive electrode and a negative electrode disposed in the outer package. The negative electrode comprises a transition metal oxide as a negative electrode active material, The outer packaging body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can. The negative electrode can faces the substrate, The flat secondary battery is configured to be arranged outside the substrate when viewed from the rotation center of the tire.

2. The multifunctional tire according to claim 1, wherein: The transition metal oxide is a composite oxide containing lithium and titanium.

3. The multifunctional tire according to claim 1 or 2, wherein: The positive electrode can is located on the side opposite to the substrate with respect to the negative electrode can.

4. A manufacturing method is a manufacturing method of a multifunctional tire, the manufacturing method comprising: a step of preparing a device including a substrate and a flat secondary battery; The step of preparing a tire configured to rotate about a rotation center; as well as The step of fixing the device to the tire, wherein the flat secondary battery is connected to the substrate via a terminal and the flat secondary battery is embedded in a resin, The flat secondary battery includes an outer package, and a positive electrode and a negative electrode disposed in the outer package. The negative electrode comprises a transition metal oxide as a negative electrode active material, The outer packaging body includes a bottomed cylindrical positive electrode can and a bottomed cylindrical negative electrode can. The negative electrode can faces the substrate, The step of fixing the device to the tire includes the step of fixing the device to the tire so that the flat secondary battery is arranged outside the substrate when viewed from the rotation center of the tire.

5. The manufacturing method according to claim 4, wherein: The transition metal oxide is a composite oxide containing lithium and titanium.

6. The manufacturing method according to claim 4 or 5, wherein: The positive electrode can is located on the side opposite to the substrate with respect to the negative electrode can.

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