Battery charging method

Abstract

The invention provides a charging method according to the state of a positive electrode at the start of charging, and the charging characteristics of a battery are improved. A method for charging a battery having a positive electrode containing a positive electrode active material represented by LixMO2 (where M is one or more selected from the group consisting of Co, Ni, Mn, and Al) in the positive electrode, determines whether or not first charging is necessary on the basis of an x value at the start of battery charging, and when it is determined that the first charging is necessary, performs second charging and third charging in this order after the first charging, and when it is determined that the second charging is necessary, performs third charging after the second charging. When it is determined that the first charging is not necessary, a second charging in which the current value is 1 C to 5 C and the charging time is 10 seconds to 30 seconds, the second charging being a constant current charging, and the third charging being a constant voltage charging, are performed in this order.

Description

Technical Field

[0001] The invention disclosed in this specification, etc. (hereinafter sometimes referred to as "the present invention" in this specification, etc.) relates to a power storage device (sometimes referred to as a battery, a secondary battery, a power storage module, etc.), etc. In particular, it relates to a lithium-ion battery. In addition, one embodiment of the present invention relates to a battery control circuit, a battery protection circuit, a power storage device, an electronic device, and their operating methods.

[0002] In addition, the present invention relates to an object, a method or a manufacturing method. In addition, the present invention relates to a process, a machine, a product or a composition of matter. In addition, the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, an electronic device, a vehicle or a method of operating the same. Background Art

[0003] In recent years, the research and development of various power storage devices such as lithium-ion batteries, lithium-ion capacitors and air batteries has become increasingly popular. In particular, with the development of the semiconductor industry such as mobile phones, smartphones or portable information terminals such as notebook computers, portable music players, digital cameras, medical equipment or electric vehicles such as hybrid electric vehicles (HV), electric vehicles (EV) or plug-in hybrid electric vehicles (PHV), the demand for high-output and high-energy-density lithium-ion batteries has increased. As a rechargeable energy supply source, lithium-ion batteries have become a necessity in the modern information society.

[0004] The charging and discharging characteristics of lithium-ion batteries vary depending on the external environment of the battery and the internal state of the battery. For example, it is known that in a low temperature environment, that is, when the temperature of the battery is low, the charging capacity and discharge capacity of lithium-ion batteries decrease. In addition, it is known that when lithium is precipitated on the negative electrode, the risk of internal short circuit increases and the precipitated lithium falls off from the negative electrode, thereby reducing the amount of lithium that contributes to charging and discharging. In addition, it is known that the internal resistance of the battery changes depending on the state of the active material inside the battery (crystal structure, etc.), making it difficult to charge quickly. As the active material of the battery, lithium cobalt oxide and the like are known as positive electrode active materials (Non-Patent Document 1), and graphite and the like are known as negative electrode active materials.

[0005] In view of this, a storage unit has been proposed that can warm the battery by pulse charging and discharging when a storage device is provided in a low temperature environment (Patent Document 1). In addition, as a countermeasure to lithium deposition, which is a problem in rapid charging, a charging method has been proposed that allows a reverse pulse current to flow during charging (Patent Document 2). [Prior technical literature] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2002-125326 [Patent Document 2] Japanese Patent Application Publication No. 2014-187002 [Non-patent literature]

[0007] [Non-patent document 1] GG Amucci et al., "CoO2, The End Member of the Li x CoO2Solid Solution” J.Electrochem.Soc.143(3)1114(1996). Summary of the invention Technical problem to be solved by the invention

[0008] Patent Document 1 discloses a charging method in which, when a power storage device is provided in a low-temperature environment, pulse discharge is repeated to increase the temperature of the battery using Joule heat.

[0009] Patent Document 2 proposes a countermeasure against lithium deposition in order to achieve rapid charging. Specifically, a charging method is disclosed in which a reverse pulse current is passed during charging to dissolve lithium deposits present on a negative electrode.

[0010] However, neither Patent Document 1 nor Patent Document 2 discloses a charging method that corresponds to the state of the active material inside the battery, specifically, the state (crystal structure, etc.) of the positive electrode active material contained in the positive electrode.

[0011] In view of this, one of the purposes of one embodiment of the present invention is to provide a charging method for a power storage device according to the state of a positive electrode. In addition, one of the purposes of one embodiment of the present invention is to provide a charging method according to the state of a positive electrode active material. In addition, one of the purposes of one embodiment of the present invention is to provide a charging method according to the crystal structure of a positive electrode active material. In addition, one of the purposes of one embodiment of the present invention is to improve the charging characteristics of a battery by providing such a charging method.

[0012] Note that the description of these objectives does not prevent the existence of other objectives. One embodiment of the present invention does not need to achieve all of the above objectives. Objectives other than the above objectives can be extracted from the description of the specification, drawings, and claims. Solutions to technical problems

[0013] One embodiment of the present invention is a method for charging a battery in which the charging method differs depending on the state of a positive electrode at the start of charging.

[0014] One embodiment of the present invention is a positive electrode containing Li xA charging method for a battery with a positive electrode active material represented by MO2, wherein M is one or more selected from Co, Ni, Mn and Al, and whether a first charge is required is determined based on the x value at the start of battery charging. When it is determined that the first charge is required, a second charge and a third charge are performed in sequence after the first charge. When it is determined that the first charge is not required, a second charge and a third charge are performed in sequence. In the first charge, the current value is greater than 1C and less than 5C and the charging time is greater than 10 seconds and less than 30 seconds. The second charge is constant current charging, and the third charge is constant voltage charging.

[0015] In the above charging method, when the x value is within the range of 0.80 to 1.0, it can be determined that the first charging is necessary.

[0016] In the above-described battery charging method, when the value of x is within a range of 0.40 to 0.60, it can be determined that the first charging is necessary.

[0017] In the above battery charging method, when the x value is in the range of 0.80 to 1.0 or in the range of 0.40 to 0.60, it can be determined that the first charging is necessary.

[0018] In any of the above-mentioned battery charging methods, whether the first discharge is required is determined based on the x value at the start of battery charging. When it is determined that the first discharge is required, the second charge and the third charge are sequentially performed after the first discharge. When it is determined that the first discharge is not required, the second charge and the third charge are sequentially performed, and the first discharge has a current value of not less than 1C and not more than 5C, and the discharge time is not less than 10 seconds and not more than 30 seconds.

[0019] In the above battery charging method, when the value of x is within the range of 0.15 to 0.20, it is determined that the first discharge is necessary. Effects of the Invention

[0020] According to one embodiment of the present invention, a charging method according to the state of the positive electrode can be provided. In addition, according to one embodiment of the present invention, a charging method according to the state of the positive electrode active material can be provided. In addition, according to one embodiment of the present invention, a charging method according to the crystal structure of the positive electrode active material can be provided. By providing such a charging method, the charging characteristics of the battery can be improved.

[0021] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above effects can be extracted from the description of the specification, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A It shows Lix Graph showing the relationship between the x and c axis lengths of CoO2. Figure 1B It is a diagram illustrating the crystal structure of LiCoO2. Figure 2 This is a diagram for explaining a battery charging method. Figure 3 is a flowchart illustrating a method of charging a battery. Figure 4A and Figure 4B This is a diagram for explaining a battery charging method. Figure 5 This is a diagram for explaining a battery charging method. Figure 6 is a flowchart illustrating a method of charging a battery. Figure 7 is a flowchart illustrating a method of charging a battery. FIG. 8A to FIG. 8D It is a diagram for explaining a configuration example of a power storage device. Fig.9A This is an exploded perspective view of a coin-type secondary battery. Fig. 9B is a perspective view of a coin-type secondary battery. Fig. 9C It is a cross-sectional stereogram. Fig. 10A An example of a cylindrical secondary battery is shown. Fig. 10B This is an example of a cross-sectional structure of a cylindrical secondary battery. Fig. 10C A plurality of examples of cylindrical secondary batteries are shown. Fig. 10D An example of a power storage system including a plurality of cylindrical secondary batteries is shown. Fig.11A and Fig. 11B is a diagram illustrating an example of a secondary battery, Fig. 11C It is a diagram showing the internal state of a secondary battery. FIG. 12A to FIG. 12C It is a diagram for explaining an example of a secondary battery. Fig.13A and Fig. 13B It is a diagram showing the appearance of a secondary battery. FIG. 14A to FIG. 14C It is a diagram for explaining a method for manufacturing a secondary battery. FIG. 15A to FIG. 15C A structural example of a battery pack is shown. Fig.16A is a perspective view showing a power storage module according to one embodiment of the present invention. Fig. 16B This is the block diagram of the power storage module. Fig. 16C is a block diagram of a vehicle including a power storage module. 17A to 17D It is a diagram illustrating an example of a transport vehicle. Fig.17E This is a diagram illustrating an example of an artificial satellite. Fig.18A and Fig.18B It is a diagram for explaining a power storage device according to one embodiment of the present invention. Fig.19A is a diagram showing an electric bicycle, Fig.19B is a diagram showing a secondary battery of an electric bicycle, Fig.19C It is a figure explaining a small motorcycle. FIG. 20A to FIG. 20D It is a diagram for explaining an example of an electronic device. Fig.21A Showing an example of a wearable device, Fig. 21B showing a perspective view of a watch type device, Fig. 21C It is a diagram illustrating the side view of a wristwatch-type device. Modes for Carrying Out the Invention

[0023] The embodiments are described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and a person skilled in the art can easily understand that the mode and details can be transformed into various forms without departing from the purpose and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents described in the embodiments shown below.

[0024] Note that in the structure of the invention described below, the same symbols are used in common between different drawings to show the same parts or parts with the same function, and their repeated descriptions are omitted. In addition, when showing parts with the same function, the same hatching is sometimes used without special additional symbols.

[0025] In addition, for ease of understanding, the positions, sizes, and ranges of various components shown in the drawings may not represent their actual positions, sizes, and ranges. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and ranges disclosed in the drawings.

[0026] Note that, unless otherwise specified, the following embodiment modes and examples can be implemented in combination with the embodiment modes and examples described in this specification and the like as appropriate.

[0027] In this specification, etc., "electronic equipment" refers to any device having a power storage device. An electro-optical device having a power storage device, an information terminal device having a power storage device, etc. are all electronic equipment.

[0028] In this specification, "power storage device" refers to a device having a power storage function and all devices including a device having a power storage function, also called a power storage module. For example, batteries such as lithium-ion batteries (also called "secondary batteries"), lithium-ion capacitors, and electric double layer capacitors are all included in the category of power storage devices.

[0029] In addition, in this specification, etc., the space group is represented by a short notation using the international symbol (or Hermann-Mauguin symbol). In addition, the Miller index is used to represent the crystal plane and the crystal direction. Each face representing the crystal plane is represented by "()". (Negative symbol) is used to represent the space group, the crystal plane and the crystal direction, instead of attaching a superscript horizontal line to the number. In addition, "[]" is used to represent the individual orientation of the orientation within the crystal, "<>" is used to represent the collective orientation of all equivalent orientations, "()" is used to represent the individual face of the crystal plane, and "{}" is used to represent the collective face with equivalent symmetry. In addition, in general, in order to easily understand the structure, the trigonal system represented by the space group R-3m is represented by a composite hexagonal lattice of the hexagonal lattice. In this specification, etc., when there is no special explanation, the space group R-3m is also represented by a composite hexagonal lattice. In addition, sometimes (hkil) is used as the Miller index in addition to (hkl). Here, i is -(h+k).

[0030] In addition, h, k, i, and l may represent any integer greater than 1. For example, (001) includes (001), (003), and (006).

[0031] In addition, the space group of the crystal structure is identified by XRD, electron diffraction, neutron diffraction, etc. Therefore, in this specification, it can be said that belonging to a certain space group or a space group means being identified as a certain space group.

[0032] In this specification, etc., the theoretical capacity of the positive electrode active material refers to the amount of electricity when all the lithium that can be embedded and separated in the positive electrode active material is separated. For example, the theoretical capacity of LiCoO2 is 274mAh / g, the theoretical capacity of LiNiO2 is 275mAh / g, and the theoretical capacity of LiMn2O4 is 148mAh / g.

[0033] In addition, for example, Li x x in CoO2 (Li occupancy rate at lithium position) represents the amount of lithium remaining in the positive electrode active material that can be inserted and removed. In the case of the positive electrode active material in a secondary battery, x = (theoretical capacity - charging capacity) / theoretical capacity. For example, when a secondary battery using LiCoO2 as the positive electrode active material is charged to 219.2 mAh / g, it can be said that Li 0.2 CoO2 or x=0.2.

[0034] Note that in this specification, etc., ordinal numbers such as "first" and "second" are added for convenience, but they do not limit the number of components or the order of components (for example, the order of processes or the order of stacking). In addition, the ordinal numbers added to components in one part of this specification may not be consistent with the ordinal numbers added to the components in other parts of this specification or claims.

[0035] In addition, in this specification, "electrode" and "wiring" do not limit their components in terms of function. For example, sometimes an "electrode" is used as a part of a "wiring", and vice versa. Furthermore, "electrode" and "wiring" also include a case where a plurality of "electrodes" and "wiring" are formed as one.

[0036] In addition, when transistors of different polarities are used or when the direction of current changes during circuit operation, the functions of the source and the drain may be interchanged. Therefore, in this specification, the source and the drain may be interchanged.

[0037] In this specification, "electrical connection" includes connection through "an element having some kind of electrical function". Here, "an element having some kind of electrical function" is not particularly limited as long as it can transmit and receive electrical signals between the connected objects. For example, "an element having some kind of electrical function" includes switching elements such as transistors, resistors, inductors, capacitors, and other elements having various functions in addition to electrodes and wiring.

[0038] (Implementation Method 1) This embodiment will be described below.

[0039] One embodiment of the present invention is a power storage device that can change the charging method according to the state of the positive electrode at the start of charging. The power storage device includes a battery, the battery including a positive electrode, a negative electrode and an electrolyte. The positive electrode includes Li x The positive electrode active material represented by MO2, M is one or more selected from Co, Ni, Mn and Al. x The positive electrode active material represented by MO2 has a layered rock salt type crystal structure belonging to the space group R-3m.

[0040] As Li x The positive electrode active material represented by MO2 may be, for example, any one or more of lithium cobalt oxide, lithium cobalt-nickel oxide, lithium nickel-cobalt-manganese oxide, lithium nickel-cobalt-aluminum oxide, and lithium nickel-manganese-aluminum oxide.

[0041] As the lithium cobalt oxide, for example, lithium cobalt oxide to which magnesium and fluorine are added can be used. In addition, lithium cobalt oxide to which magnesium, fluorine, aluminum, and nickel are added is preferably used.

[0042] As the cobalt-nickel lithium oxide, for example, cobalt-nickel lithium oxide to which magnesium and fluorine are added can be used. In addition, cobalt-nickel lithium oxide to which magnesium, fluorine and aluminum are added is preferably used. In addition, in the cobalt-nickel lithium oxide, the number of cobalt atoms is greater than the number of nickel atoms.

[0043] As nickel-cobalt-lithium manganese oxide, for example, nickel-cobalt-lithium manganese oxide having a ratio of nickel atoms, cobalt atoms and manganese atoms of nickel:cobalt:manganese = 1:1:1, nickel:cobalt:manganese = 6:2:2, nickel:cobalt:manganese = 8:1:1 and nickel:cobalt:manganese = 9:0.5:0.5, and nickel-cobalt-lithium manganese oxides having ratios close to these ratios can be used.

[0044] In Li x In the positive electrode active material represented by MO2, when the amount of lithium in the positive electrode active material changes due to charging, discharging, etc., the crystal structure changes. Figure 1A As an example, lithium cobalt oxide (Li x CoO2) is the ratio of lithium in the x-axis to the c-axis. Figure 1A This is a graph created with reference to Non-Patent Document 1.

[0045] exist Figure 1A In the graph, the x value of 1.0 on the horizontal axis refers to LiCoO2, which is the positive electrode active material in the positive electrode of the battery (black circle in the graph). In addition, when charging, the x value on the horizontal axis is less than 1.0 (white circle in the graph). That is, the x value moving to the right along the horizontal axis of the graph refers to charging. In addition, the battery can be charged and discharged when x is within the range of 0.15 or more and 1.0 or less.

[0046] like Figure 1A As shown, the positive electrode active material having a layered rock salt type crystal structure belonging to the space group R-3m, such as lithium cobalt oxide, tends to gradually increase the c-axis length from the fully discharged state (x = 1.0) due to charging until x reaches about 0.5, and then the c-axis length gradually decreases. In addition, the c-axis length is shorter than the c-axis length in the fully discharged state when further charged.

[0047] Figure 1B 1 is a diagram illustrating the crystal structure of lithium cobalt oxide having a layered rock salt type crystal structure belonging to the space group R-3m. Figure 1B The CoO2 layer and the Li layer are arranged alternately along the c-axis direction, and both the CoO2 layer and the Li layer are arranged parallel to the (001) plane. That is, the diffusion path of lithium ions also exists parallel to the (001) plane, and the position where lithium ions enter and exit is at the end of the Li layer. Therefore, it can be considered that lithium ions are easier to embed and detach when the c-axis length is longer than when the c-axis length is shorter.

[0048] In view of this, in the power storage device of one embodiment of the present invention, when the charge rate (SOC: State Of Charge) at the start of charging is low and the c-axis length of the positive electrode active material is short, Figure 2 The charging method shown is used for charging. Low charging rate and short c-axis length refer to, for example, x In the positive electrode active material represented by MO2, x is greater than or equal to 0.55 and less than or equal to 1.0, preferably greater than or equal to 0.70 and less than or equal to 1.0, and more preferably greater than or equal to 0.80 and less than or equal to 1.0. In addition, taking the state where SOC=100% is defined as x=0.15 as an example, a low charging rate and a short c-axis length, for example, refer to an SOC of greater than or equal to 0% and less than or equal to 53%, preferably greater than or equal to 0% and less than or equal to 35%, and more preferably greater than or equal to 0% and less than or equal to 24%.

[0049] Next, explain Figure 2 The charging method shown. Figure 2 Schematic diagram for explaining a method for charging a battery according to one embodiment of the present invention, wherein the vertical axis represents current and the horizontal axis represents time. Figure 2 In the charging, the first charging Ch1, the rest Re, the second charging Ch2 and the third charging Ch3 are performed in sequence. Compared with the second charging Ch2 and the third charging Ch3, the first charging Ch1 is a charging with a large current and a short time. The second charging Ch2 is a constant current charging, and the third charging Ch3 is a constant voltage charging.

[0050] As the conditions of the first charge Ch1, for example, it is preferred that the current value Ip is 1C or more and 5C or less, and the charging time is 10 seconds or more and 30 seconds or less. In addition, the rest Re refers to a period during which charging and discharging are not performed. If the rest Re period is long, the influence of the first charge Ch1 is reduced, so the rest Re is preferably a period longer than 0 seconds and less than 30 seconds. Alternatively, the rest Re may not be performed.

[0051] By performing the first charge Ch1, lithium ions are released from the surface of the positive electrode active material using the exposed region of the end of the Li layer as an exit. That is, as a transition state, the lithium ion concentration near this region decreases, and the charge rate is high (x is small). That is, according to Figure 1A As shown in the relationship, the c-axis length near this region is long, and lithium ions are easily inserted and removed. By being in this state, the subsequent charging can be carried out smoothly. In other words, the charging characteristics of the battery can be improved.

[0052] In addition, as the condition of the second charge Ch2, for example, a current value of 0.1C to 3C, preferably 0.5C to 2C, can be used. The second charge Ch2 is stopped when a predetermined voltage is reached. In addition, the predetermined voltage is the same as the constant voltage condition of the third charge Ch3 described later.

[0053] In addition, as a condition of the second charge Ch2, for example, a voltage of 4.0 V or more and 4.7 V or less can be used. The third charge Ch3 is preferably stopped when the current value is lower than a predetermined current value. In addition, the predetermined current value can be a current value of about 1 / 10 of the second charge Ch2, but is not limited thereto.

[0054] [Charging process 1 of power storage device] Regarding the above charging method, Figure 3 A flow chart illustrating the charging process is shown.

[0055] When the battery charging starts, first, in step S1, Li x MO2 represents x in the positive electrode active material. x can be calculated from the charging rate of the battery. For example, x can be calculated from the value of the charging rate of the battery using a lookup table included in the charging control IC of the power storage device.

[0056] As a method for calculating the charging rate, there is a method of calculating the charging rate based on the value of the open circuit voltage of the battery using a lookup table included in the charging control IC of the power storage device. In this case, the value of x can also be calculated based on the value of the open circuit voltage of the battery using a lookup table included in the charging control IC of the power storage device. In addition, the current flowing through the battery can be measured using a coulomb meter, and the charging rate can be calculated based on the accumulated charge. In addition, the charging rate can also be calculated using a regression model based on data such as the battery voltage and the current flowing through the battery.

[0057] In addition, as a calculation of Li x The method for determining x in the positive electrode active material represented by MO2 is to measure the internal resistance of the battery and then calculate x from the value of the internal resistance using a lookup table included in the charge control IC of the power storage device.

[0058] Next, in step S2, it is determined whether the first charging Ch1 is required. Specifically, it is determined whether the x value calculated in step S1 is within the first range. The first range refers to the range of x values ​​in the state where the charging rate is low and the c-axis length is short as described above. In the above example, the first range refers to the range of x values ​​in the state where the charging rate is low and the c-axis length is short. x In the positive electrode active material represented by MO2, x is 0.55 or more and 1.0 or less, preferably 0.70 or more and 1.0 or less, and more preferably 0.80 or more and 1.0 or less.

[0059] In step S2, when the value of x is within the first range (in the case of YES), the process proceeds to step S3. Alternatively, in step S2, when the value of x is outside the first range (in the case of NO), the process proceeds to step S5.

[0060] When entering step S3, the first charging Ch1 starts. The conditions of the first charging Ch1 are the same as Figure 2 The conditions are the same as those shown in the description of . After the first charging Ch1 is completed, the process proceeds to step S5 after the pause in step S4. Alternatively, after the first charging Ch1 is completed, the process proceeds to step S5 without the pause in step S4. Figure 2 The rest was performed under the same conditions as those shown in the description.

[0061] In step S5, the second charging Ch2 is performed. The conditions of the second charging Ch2 are the same as Figure 2 The conditions are the same as those shown in the description of . When the battery voltage reaches a predetermined voltage due to the second charging Ch2, the process proceeds to step S6.

[0062] In step S6, the third charging Ch3 is performed. The conditions of the third charging Ch3 are the same as Figure 2 The conditions are the same as those shown in the description of . The second charging Ch2 of step S5 and the third charging Ch3 of step S6 are preferably performed continuously.

[0063] When the third charging Ch3 of step S6 is finished, Figure 3 The charging process shown is completed.

[0064] By adopting Figure 3 The charging process shown can be charged only when necessary using the first charging method Ch1, thereby efficiently charging the battery. Figure 3 An illustration of the charging process is shown.

[0065] Next, use Figure 4A Description Lithium cobalt oxide (Li x The relationship between the amount of lithium in CoO2 and resistance. Figure 4A The horizontal axis and Figure 1A Similarly, the vertical axis represents the reaction resistance of lithium cobalt oxide. Figure 4A In the example of lithium cobalt oxide shown, the reaction resistance is high when the range of x is near x = 1.0. Also, the reaction resistance is high when the range of x is near x = 0. Also, the reaction resistance is sometimes high when the range of x is near x = 0.5.

[0066] In the vicinity of x = 1.0, especially in the range of x with high reaction resistance such as the range of x being greater than 0.8 and less than 1.0, it can be considered that due to the high occupancy rate of the lithium position in the lithium cobalt oxide, the lithium ions are not easy to migrate, so the reaction resistance is relatively high. In addition, when x = 0.2 or near x = 0, it can be considered that the energy required to extract lithium ions from the lithium position of the lithium cobalt oxide becomes larger, so the reaction resistance becomes higher. In addition, when x = 0.5 or so, the lithium ions are sometimes arranged in the lithium position of the lithium cobalt oxide. Lithium ion arrangement refers to the state in which lithium ions are irregularly detached during charging, that is, the lithium ions are regularly reconfigured in the lithium position from the state in which the lithium ions remain irregularly. That is, when x = 0.5 or so, the reaction resistance sometimes increases due to the influence of the lithium ion arrangement.

[0067] In a method for charging a power storage device according to one embodiment of the present invention, Figure 2 The first charging Ch1 described in the above description can smoothly carry out the subsequent charging. Figure 4A The first charging Ch1 is performed within the range of x where the reaction impedance is high.

[0068] Figure 4B yes Figure 4A 1 , 2 , 3 , and 5 , are shown as ranges of x. At this time, it is preferred that the first charge Ch1 be performed when charging of the power storage device is started within the first range R1 and the third range R3.

[0069] In addition, according to Figure 1A In the fifth range R5, the c-axis of the positive electrode active material becomes longer by discharging the battery. Figure 2 During the first charging Ch1 described in the above, the c-axis is shortened. Therefore, when charging starts in the fifth range R5, it is preferred that Figure 5 The first discharge DCh1 is performed as shown. By performing the charging of the first discharge DCh1 in the fifth range R5, the subsequent charging can be performed smoothly.

[0070] illustrate Figure 5 The charging method shown. Figure 5 Schematic diagram for explaining a method for charging a battery according to one embodiment of the present invention, wherein the vertical axis represents current and the horizontal axis represents time. Figure 5 The first discharge DCh1, the rest Re, the second charge Ch2 and the third charge Ch3 are performed in sequence. Compared with the second charge Ch2 and the third charge Ch3, the first discharge DCh1 is a charge with a large current and a short time. The second charge Ch2 is a constant current charge, and the third charge Ch3 is a constant voltage charge.

[0071] As the conditions of the first discharge DCh1, for example, it is preferred that the current value Idp is 1C or more and 5C or less, and the discharge time is 10 seconds or more and 30 seconds or less. In addition, the rest Re refers to a period during which charging and discharging are not performed. When the rest Re period is long, the influence of the first discharge DCh1 is reduced, so the rest Re is preferably a period longer than 0 seconds and less than 30 seconds. In addition, the rest Re period can be changed according to the state of the battery. Alternatively, the rest Re may not be performed.

[0072] Figure 5 The conditions of the second charging Ch2 and the third charging Ch3 shown can be compared with Figure 2 The conditions are the same as described in .

[0073] Note that Figure 4B In the second range R2 and the fourth range R4, when charging of the power storage device is started, the second charging Ch2 and the third charging Ch3 may be performed without performing the first charging Ch1 or the first discharging DCh1. Figure 6 and Figure 7 An example of this charging method is illustrated in FIG.

[0074] [Charging process 2 of power storage device] Figure 6 1 is a flowchart showing an example of a method for charging a power storage device according to one embodiment of the present invention. When charging of the power storage device is started, first, in step S1, Li is calculated. x MO2 represents x in the positive electrode active material. The calculation method of x is preferably the same as Figure 3 The same as step S1.

[0075] Next, in step S2, it is determined whether the first charging Ch1 is required. Specifically, it is determined whether the x value calculated in step S1 is within the first range R1 or the third range R3. The first range R1 refers to the range of x values ​​in the state where the charging rate is low and the c-axis length is short as described above. That is, the first range R1 refers to the range of x values ​​in the state where the charging rate is low and the c-axis length is short. x In the positive electrode active material represented by MO2, x is in the range of 0.80 or more and 1.0 or less. x In the positive electrode active material represented by MO2, x is 0.40 or more and 0.60 or less. In addition, the second range R2 refers to a range in which x is greater than 0.60 and less than 0.80.

[0076] In step S2, when the value of x is within the first range (in the case of yes), the process proceeds to step S3. In step S2, when the value of x is outside the first range (in the case of no), the process proceeds to step S5.

[0077] When entering step S3, the first charging Ch1 starts. The conditions of the first charging Ch1 are the same as Figure 2 The conditions are the same as those shown in the description of . After the first charging Ch1 is completed, the process proceeds to step S5 after the pause in step S4. Alternatively, after the first charging Ch1 is completed, the process proceeds to step S5 without the pause in step S4. Figure 2 The rest was performed under the same conditions as those shown in the description.

[0078] In step S5, the second charging Ch2 is performed. The conditions of the second charging Ch2 are the same as Figure 2 The conditions are the same as those shown in the description of . When the battery voltage reaches a predetermined voltage due to the second charging Ch2, the process proceeds to step S6.

[0079] In step S6, the third charging Ch3 is performed. The conditions of the third charging Ch3 are the same as Figure 2 The conditions are the same as those shown in the description of . The second charging Ch2 of step S5 and the third charging Ch3 of step S6 are preferably performed continuously.

[0080] At the end of the third charge in step S6, Figure 6 The charging process shown is completed.

[0081] By adopting Figure 6 The charging process shown can use the charging method of the first charging Ch1 to charge only when needed, thereby efficiently charging the battery.

[0082] [Charging process 3 of power storage device] Figure 7 1 is a flowchart showing an example of a method for charging a power storage device according to one embodiment of the present invention. When charging of the power storage device is started, first, in step S1, Li is calculated. x MO2 represents x in the positive electrode active material. The calculation method of x is preferably the same as Figure 3 The same as step S1.

[0083] Next, in step S2, it is determined whether the first charging Ch1 is required. Specifically, it is determined whether the x value calculated in step S1 is within the first range or the third range. The first range refers to the range of x values ​​in the state where the charging rate is low and the c-axis length is short as described above. That is, the first range R1 refers to the range of x values ​​in the state where the charging rate is low and the c-axis length is short. x In the positive electrode active material represented by MO2, x is in the range of 0.80 or more and 1.0 or less. x In the positive electrode active material represented by MO2, x is 0.40 or more and 0.60 or less. In addition, the second range R2 refers to a range in which x is greater than 0.60 and less than 0.80.

[0084] In step S2, if the value of x is within the first range or the third range (if yes), the process proceeds to step S3. Alternatively, in step S2, if the value of x is outside the first range or the third range (if no), the process proceeds to step S2-2.

[0085] When entering step S3, the first charging Ch1 starts. The conditions of the first charging Ch1 are the same as Figure 2 The conditions are the same as those shown in the description of . After the first charging Ch1 is completed, the process proceeds to step S5 after the pause in step S4. Alternatively, after the first charging Ch1 is completed, the process proceeds to step S5 without the pause in step S4. Figure 2 The rest was performed under the same conditions as those shown in the description.

[0086] When entering step S2-2, it is determined whether the first discharge DCh1 is required. Specifically, it is determined whether the x value calculated in step S1 is within the fifth range. The fifth range R5 refers to the range of Li x In the positive electrode active material represented by MO2, x is 0.15 or more and 0.20 or less. In addition, the fourth range R2 refers to a range in which x is greater than 0.20 and less than 0.40.

[0087] In step S2-2, when the value of x is within the fifth range (if yes), the process proceeds to step S2-3. Alternatively, in step S2-2, when the value of x is outside the fifth range (if no), the process proceeds to step S5.

[0088] When entering step S2-3, the first discharge DCh1 starts. The conditions of the first discharge DCh1 are the same as Figure 5 The conditions are the same as those shown in the description of . After the first discharge DCh1 is completed, the process proceeds to step S5 after the pause of step S4. Alternatively, after the first discharge DCh1 is completed, the process proceeds to step S5 without the pause of step S4.

[0089] In step S5, the second charging Ch2 is performed. The conditions of the second charging Ch2 are the same as Figure 2 The conditions are the same as those shown in the description of . When the battery voltage reaches a predetermined voltage due to the second charging Ch2, the process proceeds to step S6.

[0090] In step S6, the third charging Ch3 is performed. The conditions of the third charging Ch3 are the same as Figure 2 The conditions are the same as those shown in the description of . The second charging Ch2 of step S5 and the third charging Ch3 of step S6 are preferably performed continuously.

[0091] When the third charging Ch3 of step S6 is finished, Figure 7 The charging process shown is completed.

[0092] By adopting Figure 7 The charging process shown can be charged using the first charging Ch1 or the first discharging DCh1 only when needed, thereby efficiently charging the battery. Figure 7 An illustration of the charging process is shown.

[0093] [Electricity storage device] FIG. 8 is a diagram illustrating a configuration example of a power storage device.

[0094] Fig. 8A 1 is a circuit diagram showing the electrical connection relationship among the battery 10 , the IC (Integrated Circuit) 31 , the current detection element 34 , the FET 36 , the FET 37 , the external terminal 51 , and the external terminal 52 in the power storage device 1000 .

[0095] The external terminal 51 is electrically connected to the positive terminal of the battery 10, and the external terminal 52 is electrically connected to the negative terminal of the battery 10. In addition, the power storage device 1000 is electrically connected to a power consumption unit in an electronic device or a vehicle or the like having the power storage device 1000 via the external terminal 51 and the external terminal 52. Note that the power consumption unit refers to, for example, a CPU, a memory, a display, an inverter, etc. in an electronic device, and refers to an engine, a lamp, a steering system, an inverter, etc. in a vehicle.

[0096] exist Fig. 8A In the illustrated power storage device 1000 , the positive terminal of the battery 10 is electrically connected to the VCC terminal of the IC 31 , and the negative terminal of the battery 10 is electrically connected to the GND terminal of the IC 31 .

[0097] IC31 has a function of detecting the current flowing through the batteries 10 connected in series. Fig. 8A In the embodiment, the current detection element 34 is electrically connected to the Isen terminal of IC31. The current detection element 34 is also called a current sensor. In addition, IC31 has a function of detecting the voltage of the battery 10. Fig. 8A In the embodiment, Vsen1 of IC31 is electrically connected to the positive terminal of the battery 10 , and Vsen2 of IC31 is electrically connected to the negative terminal of the battery 10 .

[0098] A Hall current sensor or a shunt resistor sensor can be used as the current detection element 34. When a Hall current sensor is used as the current detection element 34, the wiring electrically connecting the negative terminal of the battery 10 and the external terminal 52 can be provided to pass through the inside of the current detection element 34.

[0099] When a shunt resistor sensor is used as the current detection element 34, Figure 8BAs shown, the current detection element 34 includes a resistor 41 (sometimes referred to as a shunt resistor), and the terminal 200A of the resistor 41 included in the current detection element 34 is electrically connected to the negative terminal of the battery 10, and the terminal 200B is electrically connected to the external terminal 52. In addition, the terminal 200C of the resistor included in the current detection element 34 is electrically connected to the Isen terminal of the IC31, and the terminal 200D is electrically connected to the Isen' terminal (not shown) of the IC31. In addition, in Fig. 8A and Figure 8B In the illustrated structure, the wiring for the terminal 200D and IC31 may be omitted and the wiring connected to the GND terminal of IC31 may be used for detecting the current.

[0100] In this specification, a terminal refers to a part that electrically connects a battery, an IC, a FET element, etc., and there is no particular limitation on the shape of the terminal. Terminals of various shapes can be used, such as a screw shape, a lead shape, a flat plate shape, a ring shape, a socket shape, a pin shape, a hemispherical shape made of solder for BGA (Ball Grid Array), a flat plate shape for LGA (Land Grid Array), a through hole and a connection pad (also called a pad) of a PCB substrate. Note that in a battery, a part of the outer package of the battery is sometimes used as a positive terminal or a negative terminal. In this case, a part of the outer package of the battery can be used as a positive terminal or a negative terminal.

[0101] IC31 preferably has a protection function and a control function of the battery 10. As a protection function, for example, one or more of the battery's overcharge protection, over-discharge protection, over-charge current protection, over-discharge current protection, and over-temperature protection may be provided. In addition, as a control function, one or more of the charging control, the discharging control, and the cell balancing control may be provided. In other words, IC31 is preferably a battery control IC. In addition, IC31 is preferably a battery protection IC. Note that in the case where IC31 has a function mainly for cell balancing control, IC31 may also be referred to as a cell balancing control IC.

[0102] IC31 preferably has a function as a microcontroller. When IC31 has a function as a microcontroller, IC31 includes a CPU, a memory, a clock generation circuit, an input unit, and an output unit. The input unit and the output unit are sometimes collectively referred to as an I / O unit. In addition, IC31 can operate according to a program stored in the memory. In addition, a lookup table of the relationship between the open circuit voltage and the charging rate of the battery, the relationship between the open circuit voltage and x of the battery, etc. can also be stored in the memory.

[0103] in addition, Figure 8C is a diagram illustrating FET 36, Fig.8DIt is a diagram for explaining FET 37 .

[0104] like Figure 8C As shown, FET36 includes transistor 202A, diode 203A, terminal 204A, terminal 205A and terminal 206A. Terminal 204A is electrically connected to battery 10, terminal 205A is electrically connected to FET37, and terminal 206A is electrically connected to IC31. Terminal 204A is electrically connected to the drain (D) of transistor 202A and the anode of diode 203A. Note that sometimes the source and drain of a transistor are interchanged according to the applied voltage, but in order to facilitate the understanding of the circuit structure, in a p-channel transistor, the terminal with a high potential during charging is called the source and the terminal with a low potential is called the drain. In addition, in an n-channel transistor, the terminal with a high potential is called the drain and the terminal with a low potential is called the source.

[0105] The FET36 has Figure 8C In the configuration described in , the FET 36 has a function of allowing the charging current of the battery 10 to flow, a function of blocking the current, and a function of allowing the discharging current of the battery 10 to flow.

[0106] like Fig.8D As shown, FET37 includes transistor 202B, diode 203B, terminal 204B, terminal 205B and terminal 206B. Terminal 204B is electrically connected to FET36, terminal 205B is electrically connected to external terminal 51, and terminal 206B is electrically connected to IC31. Terminal 204B is electrically connected to the drain (D) of transistor 202B and the cathode of diode 203B.

[0107] The FET37 has Fig.8D In the configuration described in , the FET 37 has a function of allowing the discharge current of the battery 10 to flow, a function of blocking the current, and a function of allowing the charge current of the battery 10 to flow.

[0108] As mentioned above, in Fig. 8A In the power storage device 1000 shown, FET 36 has the function of passing and blocking the charging current of battery 10 and the function of passing the discharging current of battery 10. In addition, FET 37 has the function of passing and blocking the discharging current of battery 10 and the function of passing the charging current of battery 10.

[0109] exist Fig. 8A , an example is shown in which the power storage device 1000 includes one FET 36 and one FET 37, but the present invention is not limited to this structure. As a power storage device, a structure in which two FETs 36 are connected in parallel and two FETs 37 are connected in parallel may also be adopted. By adopting such a structure, charging and discharging using a large current can be easily performed.

[0110] The circuit including the IC 31, the voltage detection wiring, the current detection element 34, the FET 36, and the FET 37 described above is referred to as the control circuit 15 of the battery 10. That is, Fig. 8A The control circuit 15 included in the power storage device 1000 shown includes a voltage sensor for detecting the voltage of the battery 10, a voltage detection wiring, and a current sensor for detecting the current flowing in the battery 10. The control circuit 15 may include ICs other than the IC 31, such as a cell balance IC, a fuel gauge IC, and the like.

[0111] The structure, method, and the like described in this embodiment mode can be used in combination with the structure, method, and the like described in other embodiment modes as appropriate.

[0112] (Implementation Method 2) In this embodiment, the components included in the lithium ion battery are described as an example of the battery included in the battery 10. Note that although not described in this embodiment, the battery 10 may also use a battery other than the lithium ion battery such as a sodium ion battery, a nickel-hydrogen battery, or a lead storage battery.

[0113] Lithium-ion batteries include a negative electrode, a positive electrode, an electrolyte, a separator and an outer packaging body.

[0114] [negative electrode] The negative electrode includes a negative electrode active material layer and a negative electrode current collector. In addition, the negative electrode active material layer includes a negative electrode active material and may further include a conductive material and a binder.

[0115] The current collector may be, for example, a metal foil. The negative electrode may be formed by applying the slurry on the metal foil and drying it. Alternatively, the slurry may be pressed after drying. In the negative electrode, an active material layer is formed on the current collector.

[0116] The slurry is a material liquid used to form an active material layer on a current collector, and includes an active material, a binder, and a solvent, preferably mixed with a conductive material. In addition, the slurry is sometimes referred to as an electrode slurry or an active material slurry, and is sometimes referred to as a negative electrode slurry when forming a negative electrode active material layer.

[0117] <Negative Electrode Active Material> As the negative electrode active material, for example, a carbon material or an alloy material can be used.

[0118] As the carbon material, for example, graphite (natural graphite, artificial graphite), easily graphitizable carbon (soft carbon), hardly graphitizable carbon (hard carbon), carbon fiber (carbon nanotube), graphene, carbon black, etc. can be used.

[0119] As graphite, artificial graphite or natural graphite can be mentioned. As artificial graphite, for example, mesophase carbon microbeads (MCMB), coke-based artificial graphite, pitch-based artificial graphite, etc. can be mentioned. Here, spherical graphite having a spherical shape can be used as artificial graphite. For example, MCMB sometimes has a spherical shape, so it is preferred. In addition, MCMB is relatively easy to reduce its surface area, so it is sometimes preferred. As natural graphite, for example, flaky graphite, spheroidized natural graphite, etc. can be mentioned.

[0120] When lithium ions are intercalated in graphite (when lithium-graphite intercalation compounds are generated), graphite shows a potential as low as that of lithium metal (0.05 V or more and 0.3 V or less vs. Li / Li + ). As a result, lithium-ion batteries using graphite can show high operating voltages. Graphite also has the following advantages: large capacity per unit volume; relatively small volume expansion; cheap; and higher safety than lithium metal, so it is preferred.

[0121] The non-graphitizable carbon can be obtained, for example, by calcining a synthetic resin such as a phenolic resin or an organic matter derived from a plant. The non-graphitizable carbon contained in the negative electrode active material of a lithium ion battery of one embodiment of the present invention has a plane spacing of (002) plane measured by X-ray diffraction (XRD) of preferably 0.34 nm or more and 0.50 nm or less, and more preferably 0.35 nm or more and 0.42 nm or less.

[0122] In addition, as the negative electrode active material, an element that can perform a charge and discharge reaction by alloying / de-alloying reaction with lithium can be used. For example, a material containing at least one of silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium and indium can be used. The capacity of such an element is higher than that of carbon, and in particular, the theoretical capacity of silicon is high, which is 4200mAh / g. Therefore, silicon is preferably used for the negative electrode active material. In addition, compounds containing these elements can also be used. For example, SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3, InSb and SbSn can be cited. Here, an element capable of performing a charge-discharge reaction through an alloying / de-alloying reaction with lithium, a compound containing the element, and the like are sometimes referred to as an alloy-based material.

[0123] In this specification, "SiO" refers to silicon monoxide, for example. Alternatively, SiO may also be represented as SiO y Here, y is preferably a value of 1 or a value close to 1. For example, y is preferably 0.2 or more and 1.5 or less, and preferably 0.3 or more and 1.2 or less.

[0124] In addition, as the negative electrode active material, oxides such as titanium dioxide (TiO2), lithium titanium oxide (Li4Ti5O 12 ), lithium-graphite intercalation compound (Li z C6), niobium pentoxide (Nb2O5), tungsten dioxide (WO2), molybdenum oxide (MoO2), etc.

[0125] In addition, as the negative electrode active material, a nitride containing lithium and a transition metal, that is, LiN having a Li3N type structure, can be used. 3-z Me z N (Me=Co, Ni, Cu). For example, Li 2.6 Co 0.4 N3 shows a large discharge capacity (900 mAh / g, 1890 mAh / cm 3 ), so it is preferred.

[0126] When a nitride containing lithium and a transition metal is used, lithium ions are contained in the negative electrode active material, so it can be combined with a material that does not contain lithium ions, such as V2O5 and Cr3O8, which is used as a positive electrode active material, and is therefore preferred. Note that when a material containing lithium ions is used as a positive electrode active material, a nitride containing lithium and a transition metal can also be used as a negative electrode active material by previously removing the lithium ions contained in the positive electrode active material.

[0127] In addition, materials that cause conversion reactions can also be used as negative electrode active materials. For example, transition metal oxides that do not form alloys with lithium, such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO), can be used as negative electrode active materials. Materials that cause conversion reactions can also include oxides such as Fe2O3, CuO, Cu2O, RuO2, and Cr2O3, CoS 0.89 , sulfides such as NiS, CuS, nitrides such as Zn3N2, Cu3N, Ge3N4, phosphides such as NiP2, FeP2, CoP3, fluorides such as FeF3, BiF3.

[0128] Note that one negative electrode active material may be used from the above-mentioned negative electrode active materials, but a plurality of negative electrode active materials may be used in combination. For example, a combination of a carbon material and silicon, or a combination of a carbon material and silicon monoxide may be used.

[0129] In addition, as another form of the negative electrode, it can also be a negative electrode that does not contain a negative electrode active material at the end of battery manufacturing. As a negative electrode that does not contain a negative electrode active material, for example, the following negative electrode can be used, which only contains a negative electrode collector at the end of battery manufacturing, and lithium ions separated from the positive electrode active material due to battery charging are precipitated as lithium metal on the negative electrode collector to form a negative electrode active material layer. A battery using this negative electrode is sometimes called a negative electrode-free (anode-free) battery, etc.

[0130] When using a negative electrode that does not contain a negative electrode active material, a film for homogenizing the precipitation of lithium may also be included on the negative electrode current collector. As a film for homogenizing the precipitation of lithium, for example, a solid electrolyte with lithium ion conductivity can be used. As a solid electrolyte, a sulfide solid electrolyte, an oxide solid electrolyte, and a polymer solid electrolyte can be used. Among them, the film of the polymer solid electrolyte is relatively easy to form evenly on the negative electrode current collector, so it is suitable for a film for homogenizing the precipitation of lithium. In addition, as a film for homogenizing the precipitation of lithium, for example, a metal film that forms an alloy with lithium can be used. As a metal film that forms an alloy with lithium, for example, a magnesium metal film can be used. Since lithium and magnesium form a solid solution in a wider composition range, it is suitable for a film for homogenizing the precipitation of lithium.

[0131] In addition, when using a negative electrode that does not contain a negative electrode active material, a negative electrode current collector having concave and convex portions can be used. When using a negative electrode current collector having concave and convex portions, the concave portions of the negative electrode current collector are cavities that are easy to precipitate lithium contained in the negative electrode current collector, thereby preventing the shape of lithium from becoming dendritic when it precipitates.

[0132] <Adhesive> As the adhesive, for example, preferably used are rubber materials such as styrene-butadiene rubber (SBR), styrene-isoprene-styrene rubber, acrylonitrile-butadiene rubber, butadiene rubber, and ethylene-propylene-diene copolymer. In addition, fluororubber can also be used as the adhesive.

[0133] In addition, as a binder, for example, a water-soluble polymer is preferably used. As a water-soluble polymer, for example, polysaccharides can also be used. As polysaccharides, cellulose derivatives such as carboxymethyl cellulose (CMC), methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, regenerated cellulose, or starch can be used. In addition, it is more preferred to use these water-soluble polymers and the above-mentioned rubber material in combination.

[0134] Alternatively, as an adhesive, it is preferred to use materials such as polystyrene, polymethyl acrylate, polymethyl methacrylate (PMMA), sodium polyacrylate, polyvinyl alcohol (PVA), polyethylene oxide (PEO), polypropylene oxide, polyimide, polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene, polyisobutylene, polyethylene terephthalate, nylon, polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), ethylene propylene diene polymer, polyvinyl acetate, and nitrocellulose.

[0135] As the binder, a plurality of the above-mentioned materials may be used in combination.

[0136] For example, materials with particularly good viscosity regulating effects can also be used in combination with other materials. For example, although rubber materials and the like have high cohesive force and high elasticity, it is sometimes difficult to regulate viscosity when mixed in a solvent. In such a case, for example, it is preferably mixed with materials with particularly good viscosity regulating effects. As materials with particularly good viscosity regulating effects, for example, water-soluble polymers can be used. In addition, as water-soluble polymers with particularly good viscosity regulating effects, the above-mentioned polysaccharides can be used, for example, cellulose derivatives such as carboxymethyl cellulose (CMC), methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, and regenerated cellulose, or starch can be used.

[0137] Note that cellulose derivatives such as carboxymethyl cellulose, for example, can be easily used as viscosity modifiers by being converted into salts such as sodium salts and ammonium salts of carboxymethyl cellulose to improve their solubility. Due to the improved solubility, the dispersibility with active materials or other components can be improved when forming the slurry of the electrode. In this specification, etc., cellulose and cellulose derivatives used as binders for electrodes include their salts.

[0138] By dissolving the water-soluble polymer in water to stabilize its viscosity, the active material and other materials used as a binder combination, such as styrene-butadiene rubber, can be stably dispersed in an aqueous solution. In addition, because the water-soluble polymer has a functional group, it is expected to be easily and stably attached to the surface of the active material. In addition, for example, cellulose derivatives such as carboxymethyl cellulose mostly have functional groups such as hydroxyl or carboxyl groups. Because the polymers interact with each other due to the functional groups, it is expected to widely cover the surface of the active material.

[0139] When the binder covering or contacting the surface of the active material forms a film, it is also expected to be used as a passivation film to exert an effect of inhibiting the decomposition of the electrolyte. Here, a "passivation film" is a film that has no conductivity or very low conductivity. For example, when the passivation film is formed on the surface of the active material, it can inhibit the decomposition of the electrolyte at the battery reaction potential. More preferably, the passivation film can transmit lithium ions while inhibiting conductivity.

[0140] <Conductive Materials> Conductive materials are also called conductive agents or conductive aids, and carbon materials are used. By attaching conductive materials between multiple active materials, multiple active materials are electrically connected to each other and the conductivity is improved. Note that "attachment" does not only refer to the situation where the active material and the conductive material are physically in close contact, but also refers to the concept that includes the following situations: the situation where a covalent bond occurs; the situation where the Van der Waals force bonds; the situation where the conductive material covers a part of the surface of the active material; the situation where the conductive material is embedded in the surface unevenness of the active material; the situation where they are electrically connected without contact, etc.

[0141] The active material layer such as the positive electrode active material layer and the negative electrode active material layer preferably contains a conductive material.

[0142] As the conductive material, for example, one or more of carbon black such as acetylene black and furnace black, graphite such as artificial graphite and natural graphite, carbon fibers such as carbon nanofibers and carbon nanotubes, and graphene compounds can be used.

[0143] As the carbon fiber, for example, carbon fibers such as mesophase pitch carbon fibers and isotropic pitch carbon fibers can be used. In addition, as the carbon fiber, carbon nanofibers or carbon nanotubes can be used. For example, carbon nanotubes can be produced by a vapor phase growth method or the like.

[0144] The graphene compounds in this specification, etc. include graphene, multilayer graphene, multigraphene, graphene oxide, multilayer graphene oxide, multigraphene oxide, reduced graphene oxide, reduced multilayer graphene oxide, reduced multigraphene oxide, graphene quantum dots, etc. Graphene compounds refer to compounds containing carbon and having a two-dimensional structure formed by a six-membered ring composed of carbon atoms in a flat plate, sheet, etc. shape. In addition, the two-dimensional structure formed by the six-membered ring composed of carbon atoms can be called a carbon sheet. Graphene compounds may also have functional groups. In addition, graphene compounds preferably have a curved shape. In addition, graphene compounds may also be curled up like carbon nanofibers.

[0145] Alternatively, the active material layer may include metal powder or metal fiber such as copper, nickel, aluminum, silver, gold, or a conductive ceramic material as a conductive material.

[0146] The content of the conductive material in the total amount of the active material layer is preferably 1 wt % to 10 wt %, more preferably 1 wt % to 5 wt %.

[0147] Unlike granular conductive materials such as carbon black that form point contact with the active material, the graphene compound can form a surface contact with low contact resistance, so the conductivity of the granular active material and the graphene compound can be improved with a smaller amount than that of a general conductive material. Therefore, the ratio of the active material in the active material layer can be increased. As a result, the discharge capacity of the battery can be increased.

[0148] Carbon compounds in the form of particles such as carbon black and graphite or fibrous carbon compounds such as carbon nanotubes can easily enter microspaces. Microspaces refer to, for example, regions between multiple active materials. By combining carbon compounds that can easily enter microspaces and sheet-like carbon compounds such as graphene that can impart conductivity to multiple particles, the density of the electrode can be increased and a good conductive path can be formed. The battery obtained by the manufacturing method of one embodiment of the present invention can have a high unit volume capacity density and stability, so it is very effective as a vehicle-mounted battery.

[0149] <Current collector> As the current collector, metals such as stainless steel, gold, platinum, zinc, iron, copper, aluminum, titanium, and their alloys, which are highly conductive and do not alloy with carrier ions such as lithium, can be used. As the current collector, shapes such as sheets, meshes, punched metal meshes, and drawn metal meshes can be appropriately used.

[0150] In addition, as the current collector, a resin current collector can be used. As the resin current collector, for example, a resin current collector containing a resin such as polyolefin (polypropylene, polyethylene, etc.), nylon (polyamide), polyimide, vinylon, polyester, acrylic acid, polyurethane, and a particulate or fibrous conductive material (also called conductive filler) can be used.

[0151] As the conductive material contained in the resin current collector, any one or more of a conductive carbon material and a metal material such as aluminum, titanium, stainless steel, gold, platinum, zinc, iron and copper can be used. As the conductive carbon material, for example, any one or more of carbon black such as acetylene black and furnace black, graphite such as artificial graphite and natural graphite, carbon fiber such as carbon nanofiber and carbon nanotube, graphene and graphene compounds can be used. When the resin current collector is used as a positive electrode current collector, it is preferred to further include an antioxidant such as a hindered phenol material.

[0152] As the carbon fiber, for example, carbon fibers such as mesophase pitch carbon fibers and isotropic pitch carbon fibers can be used. In addition, as the carbon fiber, carbon nanofibers or carbon nanotubes can be used. For example, carbon nanotubes can be produced by a vapor phase growth method or the like.

[0153] Note that the particle size of the conductive material included in the resin current collector may have an average particle size of 10 nm to 10 μm, preferably 30 nm to 5 μm.

[0154] The thickness of the current collector is preferably 5 μm or more and 30 μm or less.

[0155] In addition, as the negative electrode current collector, it is preferable to use a material that does not alloy with carrier ions such as lithium.

[0156] [positive electrode] The positive electrode includes a positive electrode active material layer and a positive electrode current collector. The positive electrode active material layer contains a positive electrode active material and may further contain at least one of a conductive material and a binder. Note that the positive electrode current collector, conductive material, and binder described in [Negative Electrode] may be used.

[0157] The current collector may be, for example, a metal foil. The positive electrode may be formed by applying the slurry on the metal foil and drying it. Alternatively, the slurry may be pressed after drying. In the positive electrode, an active material layer is formed on the current collector.

[0158] The slurry is a material liquid used to form an active material layer on a current collector, and includes an active material, a binder, and a solvent, preferably mixed with a conductive material. In addition, the slurry is sometimes referred to as an electrode slurry or an active material slurry, and is sometimes referred to as a positive electrode slurry when forming a positive electrode active material layer.

[0159] As the positive electrode active material, the positive electrode active material described in Embodiment 1 can be used.

[0160] [Electrolytes] Examples of electrolytes are described below. As one form of electrolyte, a liquid electrolyte (also referred to as an electrolyte) containing a solvent and an electrolyte dissolved in the solvent can be used. The electrolyte is not limited to a liquid electrolyte (electrolyte) that is liquid at room temperature, and a solid electrolyte can also be used. Alternatively, an electrolyte (semi-solid electrolyte) containing both a liquid electrolyte that is liquid at room temperature and a solid electrolyte that is solid at room temperature can also be used. When a solid electrolyte or a semi-solid electrolyte is used in a battery that can be bent, the flexibility of the battery can be maintained by making a portion of the laminate inside the battery contain an electrolyte.

[0161] When a liquid electrolyte is used in a secondary battery, for example, one of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, vinyl chloride carbonate, vinylene carbonate, γ-butyrolactone, γ-valerolactone, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), methyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, 1,3-dioxane, 1,4-dioxane, ethylene glycol dimethyl ether (DME), dimethyl sulfoxide, diethyl ether, methyl diglyme, acetonitrile, benzonitrile, tetrahydrofuran, cyclopentane sulfone, sultone, etc. can be used, or two or more of the above can be used in any combination and ratio.

[0162] In addition, by using one or more ionic liquids (room temperature molten salts) with flame retardancy and low volatility as the solvent of the electrolyte, even if the internal area of ​​the secondary battery is short-circuited or overcharged, the temperature of the internal area rises and the rupture or ignition of the secondary battery can be prevented. The ionic liquid is composed of cations and anions, including organic cations and anions. As organic cations, aliphatic onium cations such as quaternary ammonium cations, tertiary sulfonium cations and quaternary phosphonium cations and aromatic cations such as imidazolium cations and pyridinium cations can be cited. In addition, as anions, monovalent amide anions, monovalent methylated anions, fluorosulfonic acid anions, perfluoroalkyl sulfonic acid anions, tetrafluoroborate anions, perfluoroalkyl borate anions, hexafluorophosphate anions or perfluoroalkyl phosphate anions can be cited.

[0163] The secondary battery of one embodiment of the present invention contains, as carrier ions, alkali metal ions such as lithium ions, sodium ions, and potassium ions, and alkaline earth metal ions such as calcium ions, strontium ions, barium ions, beryllium ions, and magnesium ions.

[0164] When lithium ions are used as carrier ions, for example, the electrolyte contains a lithium salt. As lithium salts, for example, LiPF6, LiClO4, LiAsF6, LiBF4, LiAlCl4, LiSCN, LiBr, LiI, Li2SO4, Li2B 10 Cl 10 、Li2B 12 Cl 12 , LiCF3SO3, LiC4F9SO3, LiC(CF3SO2)3, LiC(C2F5SO2)3, LiN(CF3SO2)2, LiN(C4F9SO2)(CF3SO2), LiN(C2F5SO2)2, etc.

[0165] As an example, the organic solvent described in this embodiment contains ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). When the total content of these ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate is 100 vol%, an organic solvent with a volume ratio of m:n:100 - m - n (note that 5 ≤ m ≤ 35 and 0 < n < 65) of the above-mentioned ethylene carbonate, the above-mentioned ethyl methyl carbonate, and the above-mentioned dimethyl carbonate can be used. More specifically, an organic solvent containing EC, EMC, and DMC in a volume ratio of EC:EMC:DMC = 30:35:35 can be used.

[0166] In addition, as the electrolyte, preferably, the content of granular dust or elements other than the constituent elements of the electrolyte (hereinafter, simply referred to as "impurities") is small and it is highly purified. Specifically, the ratio of impurities in the weight of the electrolyte is preferably 1% or less, more preferably 0.1% or less, and further preferably 0.01% or less.

[0167] In addition, for the purpose of improving safety, etc., a coating film (Solid Electrolyte Interphase) is formed at the interface between the electrode (active material layer) and the electrolyte, and additives such as vinylene carbonate (VC), propanesultone (PS), tert-butylbenzene (TBB), fluoroethylene carbonate (FEC), lithium bis(oxalato)borate (LiBOB), or dinitrile compounds such as succinonitrile or adiponitrile can also be added to the electrolyte. The concentration of the additive can be set to, for example, 0.1 wt% or more and 5 wt% or less in the whole solvent.

[0168] In addition, by including a polymer material capable of gelation in the electrolyte, the safety of leakage and the like is improved. As typical examples of the polymer material for gelation, silicone rubber, acrylic rubber, acrylonitrile rubber, polyethylene oxide-based rubber, polypropylene oxide-based rubber, fluoropolymer rubber, etc. can be cited.

[0169] As the polymer material, for example, polymers having a polyalkylene oxide structure such as polyethylene oxide (PEO), PVDF, polyacrylonitrile, etc., and copolymers containing the above materials can be used. For example, PVDF-HFP, which is a copolymer of PVDF and hexafluoropropylene (HFP), can be used. In addition, the formed polymer can also have a porous shape.

[0170] [Separator] When the electrolyte includes an electrolyte solution, a separator is disposed between the positive electrode and the negative electrode. As the separator, for example, the following materials can be used: fibers containing cellulose such as paper, nonwoven fabrics, glass fibers, ceramics, or synthetic fibers containing nylon (polyamide), vinylon (polyvinyl alcohol-based fibers), polyester, acrylic acid, polyolefin, polyurethane, etc. It is preferred that the separator is processed into a bag shape and disposed so as to surround either the positive electrode or the negative electrode.

[0171] The separator may have a multilayer structure. For example, a ceramic material, a fluorine material, a polyamide material or a mixture thereof may be coated on a thin film of an organic material such as polypropylene or polyethylene. As a ceramic material, for example, aluminum oxide particles or silicon oxide particles may be used. As a fluorine material, for example, PVDF or polytetrafluoroethylene may be used. As a polyamide material, for example, nylon or aromatic polyamide (meta-aramid or para-aramid) may be used.

[0172] By applying ceramic materials, the oxidation resistance can be improved, thereby suppressing the degradation of the separator during high-voltage charging, thereby improving the reliability of the secondary battery. By applying fluorine materials, it is easy to make the separator close to the electrode, which can improve the output characteristics. By applying polyamide materials, especially aromatic polyamide, the heat resistance can be improved, thereby improving the safety of the secondary battery.

[0173] For example, a mixture of aluminum oxide and aramid may be applied to both sides of a polypropylene film. Alternatively, a mixture of aluminum oxide and aramid may be applied to the surface of the polypropylene film in contact with the positive electrode and a fluorine-based material may be applied to the surface in contact with the negative electrode.

[0174] By adopting a separator with a multi-layer structure, the safety of the secondary battery can be ensured even if the thickness of the separator as a whole is small, and thus the capacity per unit volume of the secondary battery can be increased.

[0175] [Outer packaging] As the outer packaging body included in the secondary battery, for example, a metal material such as aluminum or a resin material can be used. In addition, a film-shaped outer packaging body can also be used. As the film, for example, a three-layer film can be used: a metal film with excellent flexibility such as aluminum, stainless steel, copper, nickel, etc. is arranged on a film composed of materials such as polyethylene, polypropylene, polycarbonate, ionomer, polyamide, etc., and an insulating synthetic resin film such as polyamide resin, polyester resin, etc. is also arranged on the metal film as the outer surface of the outer packaging body.

[0176] The structure, method, and the like described in this embodiment mode can be used in combination with the structure, method, and the like described in other embodiment modes as appropriate.

[0177] (Implementation method 3) In this embodiment, an example of the shape of the battery 10 will be described.

[0178] [Coin-type secondary battery] An example of a coin-type secondary battery will be described. Fig.9A This is an exploded perspective view of a coin-type (single-layer flat) secondary battery. Fig. 9B It is a three-dimensional picture of the appearance. Fig. 9C Coin-type secondary batteries are mainly used in small electronic devices.

[0179] Note that in order to easily understand the overlapping relationship (upper and lower relationship and position relationship) of components, Fig.9A A schematic diagram is used. Therefore, Fig.9A Not with Fig. 9B Exactly the same picture.

[0180] exist Fig.9A In the embodiment, the positive electrode 304, the separator 310, the negative electrode 307, the spacer 322, and the gasket 312 are stacked. Then, the negative electrode can 302, the positive electrode can 301, and the gasket are used to seal the above components. Fig.9A The gasket used for sealing is not shown. The spacer 322 and the gasket 312 are used to protect the inside or fix the position in the tank when the positive electrode tank 301 and the negative electrode tank 302 are pressed together. The spacer 322 and the gasket 312 are made of stainless steel or insulating material.

[0181] A stacked structure in which a positive electrode active material layer 306 is formed on a positive electrode current collector 305 is referred to as a positive electrode 304 .

[0182] Fig. 9B This is a perspective view of the appearance of the manufactured coin-type secondary battery.

[0183] In the coin-type secondary battery 300, a positive electrode can 301 also serving as a positive terminal and a negative electrode can 302 also serving as a negative terminal are insulated and sealed by a gasket 303 formed of polypropylene or the like. The positive electrode 304 is formed of a positive electrode current collector 305 and a positive electrode active material layer 306 provided in contact with the positive electrode current collector. In addition, the negative electrode 307 is formed of a negative electrode current collector 308 and a negative electrode active material layer 309 provided in contact with the negative electrode current collector. In addition, the negative electrode 307 is not limited to a laminated structure, and a lithium metal foil or an alloy foil of lithium and aluminum may be used.

[0184] In addition, in the positive electrode 304 and the negative electrode 307 used in the coin-type secondary battery 300 , each active material layer may be formed on one surface.

[0185] As the positive electrode can 301 and the negative electrode can 302, metals such as nickel, aluminum, and titanium, alloys thereof, or alloys of these and other metals (such as stainless steel, etc.) that are resistant to corrosion by the electrolyte can be used. In addition, in order to prevent corrosion caused by the electrolyte, etc., the positive electrode can 301 and the negative electrode can 302 are preferably covered with nickel or aluminum. The positive electrode can 301 is electrically connected to the positive electrode 304, and the negative electrode can 302 is electrically connected to the negative electrode 307.

[0186] By immersing the negative electrode 307, the positive electrode 304 and the separator 310 in an electrolyte, Fig. 9C As shown, the positive electrode can 301 is placed at the bottom, the positive electrode 304, the separator 310, the negative electrode 307 and the negative electrode can 302 are stacked in order, and the positive electrode can 301 and the negative electrode can 302 are pressed together with the gasket 303 interposed therebetween to manufacture the coin-type secondary battery 300. In the coin-type secondary battery 300, the positive electrode can 301 can be referred to as a positive terminal and the negative electrode can 302 can be referred to as a negative terminal.

[0187] By adopting the above structure, it is possible to manufacture the coin-type secondary battery 300 having a high discharge capacity and excellent cycle characteristics.

[0188] [Cylindrical secondary battery] Next, refer to Fig. 10A An example of a cylindrical secondary battery will be described. Fig. 10A As shown, the cylindrical secondary battery 616 has a positive electrode cover (battery cover) 601 on the top surface, and a battery can (external can) 602 on the side and bottom surfaces. The positive electrode cover 601 and the battery can (external can) 602 are insulated by a gasket (insulating gasket) 610. In the cylindrical secondary battery 616, the positive electrode cover 601 can be called a positive terminal and the battery can 602 can be called a negative terminal.

[0189] Fig. 10B It is a diagram schematically showing a cross section of a cylindrical secondary battery. Fig. 10B The cylindrical secondary battery shown has a positive electrode cover (battery cover) 601 on the top surface and a battery can (outer can) 602 on the side and bottom surfaces. The positive electrode cover and the battery can (outer can) 602 are insulated by a gasket (insulating gasket) 610.

[0190] A battery element is provided inside the hollow cylindrical battery can 602, in which a strip-shaped positive electrode 604 and a strip-shaped negative electrode 606 are wound around a separator 605. Although not shown, the battery element is wound around the central axis. One end of the battery can 602 is closed and the other end is open. As the battery can 602, metals such as nickel, aluminum, titanium, etc., which are resistant to corrosion by the electrolyte, their alloys, or alloys of them and other metals (such as stainless steel, etc.) can be used. In addition, in order to prevent corrosion caused by the electrolyte, the battery can 602 is preferably covered with nickel, aluminum, etc. On the inside of the battery can 602, the battery element in which the positive electrode, the negative electrode and the separator are wound is sandwiched by a pair of opposing insulating plates 608 and insulating plates 609. In addition, a non-aqueous electrolyte (not shown) is injected into the interior of the battery can 602 in which the battery element is provided. As a non-aqueous electrolyte, the same electrolyte as a coin-type secondary battery can be used.

[0191] Since the positive electrode and the negative electrode used for the cylindrical storage battery are wound, the active material is preferably formed on both surfaces of the current collector.

[0192] The positive electrode 604 is connected to the positive terminal (positive electrode current collecting wire) 603, and the negative electrode 606 is connected to the negative terminal (negative electrode current collecting wire) 607. Metal materials such as aluminum can be used for both the positive terminal 603 and the negative terminal 607. The positive terminal 603 is resistance welded to the safety valve mechanism 613, and the negative terminal 607 is resistance welded to the bottom of the battery can 602. The safety valve mechanism 613 is electrically connected to the positive electrode cover 601 through a PTC element (Positive Temperature Coefficient) 611. When the internal pressure of the battery rises to exceed a specified threshold, the safety valve mechanism 613 cuts off the electrical connection between the positive electrode cover 601 and the positive electrode 604. In addition, the PTC element 611 is a thermally sensitive resistance element whose resistance increases when the temperature rises, and limits the current by increasing the resistance to prevent abnormal heating. As a PTC element, barium titanate (BaTiO3)-based semiconductor ceramics, etc. can be used.

[0193] Fig. 10CAn example of a power storage module 615 is shown. The power storage module 615 includes a plurality of secondary batteries 616. The positive electrode of each secondary battery is in contact with and electrically connected to a conductor 624. In addition, the negative electrode of each secondary battery is in contact with and electrically connected to a conductor 625. Thus, the conductor 624 can be referred to as the positive terminal of the power storage device (battery assembly) and the conductor 625 can be referred to as the negative terminal of the power storage device (battery assembly). The conductor 624 is electrically connected to the control circuit 620 via a wiring 623. In addition, the conductor 625 is electrically connected to the control circuit 620 via a wiring 626. As the control circuit 620, a charge and discharge control circuit for performing charge and discharge, etc., or a protection circuit for preventing overcharge and / or overdischarge, etc. can be used. In addition, the control circuit 620 includes an external terminal 629 and an external terminal 630.

[0194] Fig. 10D An example of a power storage module 615 is shown. The power storage module 615 includes a plurality of secondary batteries 616, and the plurality of secondary batteries 616 are sandwiched between a conductive plate 628 (conductive plate 628A, conductive plate 628B) and a conductive plate 614 (conductive plate 614A, conductive plate 614B). The plurality of secondary batteries 616 are electrically connected to the conductive plate 628 and the conductive plate 614 through a wiring 627. The plurality of secondary batteries 616 can be connected in parallel, in series, or in series after being connected in parallel. By constituting a power storage module 615 including a plurality of secondary batteries 616, a large amount of power can be extracted. In addition, the plurality of secondary batteries 616 can be referred to as a power storage device or a battery pack. At this time, the conductive plate with the highest potential among the conductive plate 628 and the conductive plate 614 can be referred to as a positive terminal of the power storage device or a positive terminal of the battery pack. In addition, the conductive plate with the lowest potential among the conductive plate 628 and the conductive plate 614 can be referred to as a negative terminal of the power storage device or a negative terminal of the battery pack.

[0195] In addition, a temperature control device may be included between the plurality of secondary batteries 616. When the secondary battery 616 is overheated, it can be cooled by the temperature control device, and when the secondary battery 616 is overcooled, it can be heated by the temperature control device. Therefore, the performance of the power storage module 615 is not easily affected by the external temperature.

[0196] In addition, Fig. 10D In the embodiment, the power storage module 615 is electrically connected to the control circuit 620 through the wiring 621 and the wiring 622. The wiring 621 is electrically connected to the positive electrodes of the plurality of secondary batteries 616 through the conductive plate 628, and the wiring 622 is electrically connected to the negative electrodes of the plurality of secondary batteries 616 through the conductive plate 614. In addition, the control circuit 620 includes an external terminal 629 and an external terminal 630.

[0197] [Other structural examples of secondary batteries] An example of the structure of a secondary battery will be described using FIG. 11 and FIG. 12 .

[0198] Fig.11A The secondary battery 913 shown includes a winding body 950 provided with a terminal 951 and a terminal 952 inside a frame 930. The winding body 950 is impregnated with an electrolyte inside the frame 930. The terminal 952 is in contact with the frame 930, and the terminal 951 is prevented from contacting the frame 930 by an insulating material. Note that for convenience, although Fig.11A Frame 930 is shown separately in the figure, but in reality, winding body 950 is covered by frame 930, and terminals 951 and 952 extend outside frame 930. Frame 930 can be made of a metal material (such as aluminum) or a resin material.

[0199] In addition, if Fig. 11B As shown, multiple materials can also be used to form Fig.11A For example, in the frame 930 shown in FIG. Fig. 11B In the secondary battery 913 shown, a frame body 930 a and a frame body 930 b are bonded together, and a wound body 950 is provided in a region surrounded by the frame bodies 930 a and 930 b.

[0200] As the frame 930a, an insulating material such as an organic resin can be used. In particular, by using a material such as an organic resin to form the surface of the antenna, it is possible to suppress the shielding of the electric field by the secondary battery 913. In addition, if the electric field shielding caused by the frame 930a is small, the antenna can also be provided inside the frame 930a. As the frame 930b, for example, a metal material can be used.

[0201] Furthermore, Fig. 11C The structure of the wound body 950 is shown. The wound body 950 includes a negative electrode 931, a positive electrode 932, and a separator 933. The wound body 950 is formed by overlapping the negative electrode 931 and the positive electrode 932 with the separator 933 interposed therebetween to form a laminated sheet, and then winding the laminated sheet. In addition, a plurality of laminated layers consisting of the negative electrode 931, the positive electrode 932, and the separator 933 may be stacked.

[0202] Alternatively, a secondary battery 913 including a wound body 950 a as shown in FIG. 12 may be used. Fig. 12A The wound body 950a shown includes a negative electrode 931, a positive electrode 932, and a separator 933. The negative electrode 931 includes a negative electrode active material layer 931a. The positive electrode 932 includes a positive electrode active material layer 932a.

[0203] The separator 933 is wider than the negative electrode active material layer 931a and the positive electrode active material layer 932a, and is wound so as to overlap the negative electrode active material layer 931a and the positive electrode active material layer 932a. In addition, from the viewpoint of safety, the width of the negative electrode active material layer 931a is preferably wider than the positive electrode active material layer 932a. In addition, the winding body 950a of the above shape is preferred because of its good safety and productivity.

[0204] like Fig. 12B As shown, the negative electrode 931 is electrically connected to the terminal 951 by ultrasonic bonding, welding or pressing. The terminal 951 is electrically connected to the terminal 911a. In addition, the positive electrode 932 is electrically connected to the terminal 952 by ultrasonic bonding, welding or pressing. The terminal 952 is electrically connected to the terminal 911b.

[0205] like Fig. 12C As shown, the wound body 950a and the electrolyte are covered by the frame 930 to form a secondary battery 913. The frame 930 is preferably provided with a safety valve, an overcurrent protection element, etc. The safety valve opens the inside of the frame 930 according to a specified internal pressure to prevent the battery from rupturing.

[0206] like Fig. 12B As shown, the secondary battery 913 may also include a plurality of winding bodies 950a. By using a plurality of winding bodies 950a, a secondary battery 913 with a larger discharge capacity can be realized. Fig. 12A and Fig. 12B The other components of the secondary battery 913 shown can be referred to FIG. 11A to FIG. 11C Description of the secondary battery 913 shown.

[0207] <Laminated secondary battery> then, Fig.13A and Fig. 13B 1 is an external view showing an example of a laminated secondary battery. Fig.13A and Fig. 13B The battery includes a positive electrode 503, a negative electrode 506, a separator 507, an outer package 509, a positive lead electrode 510, and a negative lead electrode 511. The portion of the positive lead electrode 510 exposed to the outside of the secondary battery can be called a positive terminal, and the portion of the negative lead electrode 511 exposed to the outside of the secondary battery can be called a negative terminal.

[0208] Fig.14AIt is an appearance diagram of the positive electrode 503 and the negative electrode 506. The positive electrode 503 includes a positive electrode current collector 501, and a positive electrode active material layer 502 is formed on the surface of the positive electrode current collector 501. In addition, the positive electrode 503 has an area (hereinafter referred to as the tab area) where a portion of the positive electrode current collector 501 is exposed. The negative electrode 506 includes a negative electrode current collector 504, and a negative electrode active material layer 505 is formed on the surface of the negative electrode current collector 504. In addition, the negative electrode 506 has an area where a portion of the negative electrode current collector 504 is exposed, namely, the tab area. Note that the area or shape of the tab area of ​​the positive electrode and the negative electrode is not limited to Fig.14A Example shown.

[0209] <Method for manufacturing laminated secondary battery> Reference Fig. 14B and Fig. 14C Yes Fig.13A An example of a method for producing a laminated secondary battery whose appearance is shown in FIG. 1 is described below.

[0210] First, the negative electrode 506, the separator 507, and the positive electrode 503 are stacked. Fig. 14B The stacked negative electrode 506, separator 507, and positive electrode 503 are shown. Here, an example using five sets of negative electrodes and four sets of positive electrodes is shown. Fig. 14B The example shown can also be said to be a laminate composed of a negative electrode, a separator, and a positive electrode. Next, the tab regions of the positive electrode 503 are joined to each other, and the positive electrode lead electrode 510 is joined to the tab region of the outermost positive electrode. As the joining, ultrasonic welding or the like can be used, for example. Similarly, the tab regions of the negative electrode 506 are joined to each other, and the negative electrode lead electrode 511 is joined to the tab region of the outermost negative electrode.

[0211] Then, if Fig. 14C As shown, the negative electrode 506 , the separator 507 , and the positive electrode 503 are arranged on the outer packaging body 509 .

[0212] Below, as Fig. 14C As shown, the outer package 509 is folded along the portion indicated by the dotted line. Then, the outer periphery of the outer package 509 is joined. As the joining method, for example, heat pressing or the like can be used. At this time, in order to inject the electrolyte later, a non-joined area (hereinafter referred to as the introduction port) is provided on a part (or one side) of the outer package 509.

[0213] Next, the electrolyte is introduced into the inner side of the outer packaging body 509 from the introduction port provided in the outer packaging body 509. The electrolyte is preferably introduced under a reduced pressure atmosphere or an inert gas atmosphere. Finally, the introduction port is joined. In this way, the laminated secondary battery 500 can be manufactured.

[0214] [Battery pack example] An example of a secondary battery pack according to one embodiment of the present invention that can be wirelessly charged using an antenna will be described with reference to FIG. 15 .

[0215] Fig.15A 1 is a diagram showing the appearance of a secondary battery pack 531 , which has a thin rectangular parallelepiped shape (or a relatively thick flat plate shape). Fig. 15B 5 is a diagram for explaining the structure of a secondary battery pack 531. The secondary battery pack 531 includes a circuit board 540 and a secondary battery 513. A label 529 is attached to the secondary battery 513. The circuit board 540 is fixed by a sealing tape 515. The secondary battery pack 531 also includes an antenna 517.

[0216] The interior of the secondary battery 513 may have a structure including a wound body or a structure including a stacked body.

[0217] like Fig. 15B As shown, the secondary battery pack 531 is provided with a control circuit 590 on a circuit board 540, for example. In addition, the circuit board 540 is electrically connected to the terminal 514. In addition, the circuit board 540 is electrically connected to the antenna 517, one of the positive and negative wires 551 of the secondary battery 513, and the other of the positive and negative wires 552. Note. The positive wire may be referred to as a positive terminal and the negative wire may be referred to as a negative terminal.

[0218] In the secondary battery pack 531 , as the configuration of the secondary battery 513 and the control circuit 590 , the configuration of the power storage device 1000 described in the first embodiment and the like can be used.

[0219] In addition, if Fig. 15C As shown, it may also include a circuit system 590a disposed on the circuit board 540 and a circuit system 590b electrically connected to the circuit board 540 through the terminal 514. Note that the terminal 514 includes a plurality of terminals, including at least a high potential terminal ( Figure 1B The external terminal 51) and the low potential terminal ( Figure 1B The external terminal 52 in the embodiment.

[0220] In addition, the shape of antenna 517 is not limited to a coil shape, for example, it can be a linear or plate shape. In addition, antennas such as a planar antenna, an aperture antenna, a traveling wave antenna, an EH antenna, a magnetic field antenna, or a dielectric antenna can also be used. Alternatively, antenna 517 can also be a flat conductor. The flat conductor can also be used as one of the conductors for electric field coupling. In other words, antenna 517 can also be used as one of the two conductors possessed by a capacitor. Thus, not only electromagnetic and magnetic fields are utilized, but also electric fields can be utilized to exchange electric power.

[0221] The secondary battery pack 531 includes a layer 519 between the antenna 517 and the secondary battery 513. The layer 519 has a function of shielding the electromagnetic field from the secondary battery 513, for example. As the layer 519, a magnetic body can be used, for example.

[0222] The structure, method, and the like described in this embodiment can be used in combination with the structure, method, and the like described in other embodiments as appropriate.

[0223] (Implementation 4) In this embodiment, an example of a vehicle including a secondary battery according to one embodiment of the present invention is described with reference to Fig. 16. The secondary battery and the control circuit described in this embodiment can use the configuration of power storage device 1000 described in Embodiment 1.

[0224] As a vehicle, typically, a secondary battery can be used in a car. As a car, a new generation of clean energy vehicles such as a hybrid electric vehicle (HV), an electric vehicle (EV) or a plug-in hybrid electric vehicle (also called PHEV or PHV) can be cited, and a secondary battery can be used as one of the power sources installed in the car. Vehicles are not limited to cars. For example, as vehicles, trams, monorails, ships, submarines (submersibles, unmanned submarines), flying objects (helicopters, unmanned aircraft (drones), airplanes, rockets, satellites), electric bicycles, electric motorcycles, etc. can also be cited, and the above-mentioned vehicles can use a secondary battery of one embodiment of the present invention.

[0225] In electric vehicles, Fig. 16C As shown, as the secondary battery for main driving, first power storage devices 1301a and 1301b and a second power storage device 1311 for supplying power to an inverter 1312 for starting an engine 1304 are provided. The second power storage device 1311 is also called a cranking battery (also called a starting battery). The second power storage device 1311 only needs to have a high output and does not need to have a high capacity, so the capacity of the second power storage device 1311 is smaller than that of the first power storage devices 1301a and 1301b.

[0226] The internal structure of the first power storage device 1301a can be either Fig. 11C or Fig. 12A The winding type shown can also be used Fig.13A or Fig. 13B The stacked type shown. In addition, the first power storage device 1301a may also use an all-solid-state battery. By using an all-solid-state battery as the first power storage device 1301a, high capacity, improved safety, miniaturization, and weight reduction can be achieved.

[0227] In this embodiment, an example of connecting two power storage devices, the first power storage device 1301a and 1301b, in parallel is shown, but more than three of the above power storage devices may be connected in parallel. In addition, as long as sufficient power can be stored in the first power storage device 1301a, the first power storage device 1301b may not be provided. By forming a battery pack including a plurality of secondary batteries by the power storage device, a large amount of power can be extracted. A plurality of secondary batteries may be connected in parallel, in series, or in series after being connected in parallel. Sometimes a plurality of secondary batteries are referred to as a battery pack.

[0228] In order to cut off the electric power from the plurality of secondary batteries, the vehicle-mounted secondary battery includes a charging plug or a circuit breaker that can cut off the high voltage without using a tool, which is provided in the first power storage device 1301a.

[0229] In addition, the power of the first power storage devices 1301a and 1301b is mainly used to rotate the engine 1304, and the power is also supplied to the 42V series vehicle-mounted components (electric power steering system 1307, heater 1308, defogger 1309, etc.) through the DCDC converter 1306. In the case where the rear wheels include a rear engine 1317, the first power storage device 1301a is used to rotate the rear engine 1317.

[0230] Furthermore, the second power storage device 1311 supplies electric power to 14V series vehicle-mounted components (audio 1313 , power windows 1314 , lights 1315 , etc.) via the DCDC circuit 1310 .

[0231] Next, use Fig.16A The first power storage device 1301a will be described.

[0232] Fig.16AAn example of using nine rectangular secondary batteries 1300 as one power storage module 1415 is shown. In addition, the nine rectangular secondary batteries 1300 are connected in series, and one electrode is fixed using a fixing portion 1413 composed of an insulator and the other electrode is fixed using a fixing portion 1414 composed of an insulator. In this embodiment, an example of fixing using fixing portions 1413 and 1414 is shown, but it can also be stored in a battery storage box (also referred to as a frame). Assuming that the vehicle is vibrated or shaken from the outside (road surface, etc.), it is preferable to fix multiple secondary batteries using fixing portions 1413, 1414 or a battery storage box. In addition, one electrode is electrically connected to the control circuit unit 1320 via wiring 1421. In addition, the other electrode is electrically connected to the control circuit unit 1320 via wiring 1422. In the first power storage device 1301a, the electrode connected to the wiring 1421 or the wiring 1422 with a higher potential may be referred to as the positive terminal of the first power storage device 1301a, and the electrode with a lower potential may be referred to as the negative terminal of the first power storage device 1301a. The control circuit unit 1320 includes an external connection terminal 1325 and an external connection terminal 1326.

[0233] Alternatively, a memory circuit including a transistor using an oxide semiconductor may be used for the control circuit unit 1320. A charging control circuit or a battery control system including a memory circuit including a transistor using an oxide semiconductor is sometimes referred to as a BTOS (Battery operating system or Battery oxide semiconductor).

[0234] It is preferred to use a metal oxide used as an oxide semiconductor. For example, as a metal oxide, it is preferred to use an In-M-Zn oxide (the element M is selected from one or more of aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten and magnesium). In particular, the In-M-Zn oxide that can be applied to the metal oxide is preferably CAAC-OS (C-Axis Aligned Crystal Oxide Semiconductor) or CAC-OS (Cloud-Aligned Composite Oxide Semiconductor). In addition, In-Ga oxide and In-Zn oxide can also be used as metal oxides. CAAC-OS is an oxide semiconductor including a plurality of crystalline regions, and the c-axis of the plurality of crystalline regions is oriented in a specific direction. In addition, the specific direction refers to the thickness direction of the CAAC-OS film, the normal direction of the formed surface of the CAAC-OS film, or the normal direction of the surface of the CAAC-OS film. In addition, the crystalline region is a region having a periodicity of atomic arrangement. Note that when the atomic arrangement is viewed as a lattice arrangement, the crystalline region is also a region where the lattice arrangement is consistent.

[0235] In addition, "CAC-OS" refers to a structure in which the material is separated into a first region and a second region to form a mosaic shape, and the first region is distributed in the film (hereinafter also referred to as a cloud shape). That is, CAC-OS refers to a composite metal oxide having a structure in which the first region and the second region are mixed. Note that it is sometimes difficult to observe a clear boundary between the first region and the second region.

[0236] For example, in the CAC-OS of In-Ga-Zn oxide, based on the EDX surface analysis (mapping) image obtained by energy dispersive X-ray spectroscopy (EDX), it can be confirmed that the structure has a region with In as the main component (first region) and a region with Ga as the main component (second region) that are unevenly distributed and mixed.

[0237] When CAC-OS is used for transistors, the complementary effect of the conductivity of the first region and the insulation of the second region can give CAC-OS a switch function (a function of controlling on / off). In other words, a portion of the CAC-OS material has a conductive function and another portion has an insulating function, and the entire material has a semiconductor function. By separating the conductive function and the insulating function, each function can be maximized. Therefore, by using CAC-OS for transistors, a high on-state current (I on), high field effect mobility (μ) and good switching performance.

[0238] Oxide semiconductors have various structures, and each structure has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0239] In addition, the control circuit unit 1320 preferably uses a transistor including an oxide semiconductor because the transistor can be used in a high temperature environment. In order to simplify the process, the control circuit unit 1320 can also be formed using a unipolar transistor. The operating ambient temperature range of the transistor using an oxide semiconductor in the semiconductor layer is larger than that of the single-crystal Si transistor, that is, above -40°C and below 150°C, and the characteristic change when the secondary battery is overheated is smaller than that of the single-crystal Si transistor. The off-state current of the transistor using an oxide semiconductor is not affected by the temperature at 150°C and is below the lower limit of measurement, but the temperature dependence of the off-state current characteristics of the single-crystal Si transistor is large. For example, at 150°C, the off-state current of the single-crystal Si transistor increases, and a sufficiently large current switching ratio cannot be achieved. The control circuit unit 1320 can improve safety.

[0240] The control circuit unit 1320 using a storage circuit including a transistor using an oxide semiconductor can also be used as an automatic control device for a secondary battery for instability such as micro short circuits. As functions for solving the causes of instability such as micro short circuits, there can be cited prevention of overcharging, prevention of overcurrent, control of overheating during charging, cell balancing in a battery pack, prevention of overdischarge, a capacity meter, automatic control of charging voltage and current according to temperature, control of charging current according to the degree of degradation, detection of abnormal behavior of micro short circuits, prediction of abnormalities regarding micro short circuits, etc. The control circuit unit 1320 has at least one of the above functions. In addition, ultra-miniaturization of the automatic control device for secondary batteries can be achieved.

[0241] In addition, "micro short circuit" refers to a tiny short circuit inside the secondary battery. It is not a state where the positive and negative electrodes of the secondary battery cannot be charged or discharged due to a short circuit, but a phenomenon in which a short circuit current flows slightly in the tiny short circuit part. Since a large voltage change occurs even in a short time and in a very small part, this abnormal voltage value will affect subsequent speculation.

[0242] One of the reasons for micro short circuits is believed to be that due to repeated charging and discharging, uneven distribution of positive electrode active materials occurs, local current concentration occurs in part of the positive electrode and part of the negative electrode, and part of the separator becomes inoperative, or side reactions produce side reactants, thus causing micro short circuits.

[0243] In addition to micro short circuits, the control circuit unit 1320 detects the terminal voltage of the secondary battery and manages the charge and discharge state of the secondary battery. For example, to prevent overcharging, both the output transistor of the charging circuit and the blocking switch can be turned off at almost the same time.

[0244] then, Fig. 16B Show Fig.16A An example of a block diagram of the power storage module 1415 is shown.

[0245] The control circuit unit 1320 includes: a switch unit 1324 having at least a switch for preventing overcharge and a switch for preventing overdischarge; a control circuit 1322 for controlling the switch unit 1324; a voltage measuring unit of the first power storage device 1301a; and a PTC element 1332. In the control circuit unit 1320, the upper limit voltage and the lower limit voltage of the secondary battery used are set to control the upper limit of the current flowing from the outside or the upper limit of the output current flowing to the outside. The range above the lower limit voltage and below the upper limit voltage of the secondary battery is the recommended voltage range. When the voltage is outside this range, the switch unit 1324 functions and serves as a protection circuit. In addition, the control circuit unit 1320 controls the switch unit 1324 to prevent overdischarge and / or overcharge, so it can also be called a protection circuit. For example, when the control circuit 1322 detects a voltage that will become overcharge, the switch of the switch unit 1324 is closed to shield the current. In addition, the function of shielding the current according to the increase in temperature can also be set by setting a PTC element in the charge and discharge path. In addition, the control circuit unit 1320 includes an external terminal 1325 (+IN) and an external terminal 1326 (−IN).

[0246] The switch section 1324 can be formed by combining n-channel transistors or p-channel transistors. In addition to switches including Si transistors using single crystal silicon, power transistors such as Ge (germanium), SiGe (silicon germanium), GaAs (gallium arsenide), GaAlAs (gallium aluminum arsenide), InP (indium phosphide), SiC (silicon carbide), ZnSe (zinc selenide), GaN (gallium nitride), GaOz (gallium oxide; z is a real number greater than 0) can also be used to form the switch section 1324. In addition, the storage element using the OS transistor can be freely configured by stacking it on a circuit using the Si transistor, so it is easy to achieve integration. In addition, the OS transistor can be manufactured using the same manufacturing device as the Si transistor, so it can be manufactured at a low cost. That is, by stacking the control circuit section 1320 using the OS transistor on the switch section 1324 and integrating them, they can be formed into one chip. The volume occupied by the control circuit section 1320 can be reduced, so miniaturization can be achieved.

[0247] The first power storage device 1301a and 1301b mainly supply power to 42V series (high voltage series) vehicle-mounted equipment, while the second power storage device 1311 supplies power to 14V series (low voltage series) vehicle-mounted equipment. In many cases, the second power storage device 1311 adopts a lead-acid battery because of cost advantages. However, lead-acid batteries have the disadvantages of large self-discharge compared with lithium-ion batteries and easy deterioration due to a phenomenon called sulfation. When a lithium-ion battery is used as the second power storage device 1311, there is an advantage of no need for maintenance, but in the case of a long period of use, for example, in the case of more than three years of use, an abnormality that is difficult to distinguish at the time of manufacturing may occur. In particular, when the second power storage device 1311 of the starter inverter fails to work, there is a concern that the engine cannot be started even if the first power storage devices 1301a and 1301b have residual capacity. In order to prevent this problem from occurring, when the second power storage device 1311 is a lead-acid battery, power is supplied from the first battery to the second battery to charge in a manner that always maintains a fully charged state.

[0248] This embodiment shows an example in which both the first power storage device 1301a and the second power storage device 1311 use lithium ion batteries. The second power storage device 1311 may also use a lead acid battery, a solid-state battery, or a double-layer capacitor. For example, a solid-state battery may also be used. By using a solid-state battery as the second power storage device 1311, a high capacity can be achieved, thereby achieving miniaturization and lightness.

[0249] In addition, the regenerative energy caused by the rotation of the tire 1316 is transmitted to the engine 1304 through the transmission 1305, and is charged to the second power storage device 1311 from the engine controller 1303 or the battery controller 1302 through the control circuit unit 1321. In addition, the first power storage device 1301a is charged from the battery controller 1302 through the control circuit unit 1320. In addition, the first power storage device 1301b is charged from the battery controller 1302 through the control circuit unit 1320. In order to efficiently charge the regenerative energy, it is preferable that the first power storage devices 1301a and 1301b can be charged at a high speed.

[0250] The battery controller 1302 can set the charging voltage and charging current of the first power storage devices 1301a and 1301b, etc. The battery controller 1302 sets the charging conditions according to the charging characteristics of the secondary battery to be used and performs high-speed charging.

[0251] In addition, although not shown in the figure, when connected to an external charger, the socket of the charger or the connecting cable of the charger is electrically connected to the battery controller 1302. The power supplied from the external charger is charged to the first power storage devices 1301a and 1301b through the battery controller 1302. In addition, some chargers are provided with a control circuit without using the function of the battery controller 1302, but in order to prevent overcharging, it is preferred to charge the first power storage devices 1301a and 1301b through the control circuit unit 1320. In addition, sometimes the socket of the charger or the connecting cable of the charger is provided with a control circuit. The control circuit unit 1320 is sometimes referred to as an ECU (Electronic Control Unit). The ECU is connected to a CAN (Controller Area Network) provided in the electric vehicle. CAN is one of the serial communication standards used as an in-vehicle LAN. In addition, the ECU includes a microcomputer. In addition, the ECU uses a CPU or a GPU.

[0252] As an external charger installed in a charging station, there are 100V outlet-200V outlet or three-phase 200V and 50kW outlet, etc. In addition, it is also possible to charge by supplying power from an external charging device through a contactless power supply method.

[0253] In order to charge the battery in a short time during high-speed charging, a secondary battery that can withstand charging at a high voltage is required.

[0254] In addition, when graphene is used as a conductive material, the thickness of the electrode layer can be increased to increase the load and suppress the decrease in capacity to maintain a high capacity. That is, a secondary battery with greatly improved electrical characteristics can be realized. In particular, it is very effective for secondary batteries used in vehicles, and a longer driving distance can be achieved without increasing the ratio of the weight of the secondary battery relative to the total weight of the vehicle. Specifically, a vehicle can travel a distance of more than 500 km per charge.

[0255] Next, an example in which a secondary battery as one embodiment of the present invention is mounted on a vehicle, typically a transportation vehicle, will be described.

[0256] In addition, when Fig. 10D , Fig. 12C , Fig.16AWhen any of the secondary batteries shown in is installed in a vehicle, a new generation of clean energy vehicles such as hybrid electric vehicles (HV), electric vehicles (EV) or plug-in hybrid electric vehicles (PHV) can be realized. In addition, the secondary battery can also be installed in agricultural machinery, electric bicycles including electric-assisted bicycles, motorcycles, electric wheelchairs, electric karts, ships, submarines, airplanes, rockets, artificial satellites, space probes, planetary probes or spacecraft. The secondary battery of one embodiment of the present invention can be a high-capacity secondary battery. Therefore, the secondary battery of one embodiment of the present invention is suitable for miniaturization and lightweight, and can be suitable for use in transportation vehicles.

[0257] 17A to 17D A transport vehicle using one embodiment of the present invention is shown. Fig.17A The car 2001 shown is an electric car using an electric motor as a driving power source. Alternatively, the car 2001 is a hybrid car that can use an electric motor and an engine as the driving power. When the secondary battery is installed in the vehicle, the example of the secondary battery shown in Embodiment 3 can be set in one or more parts. Fig.17A The illustrated automobile 2001 includes a battery pack 2200 including a power storage module in which a plurality of secondary batteries are connected, and preferably also includes a charge control device electrically connected to the power storage module.

[0258] In addition, in the automobile 2001, the secondary battery of the automobile 2001 can be charged by supplying power from an external charging device using a plug-in method or a contactless power supply method. When charging, the charging method or the specifications of the connector can be appropriately performed in accordance with the methods specified by CHAdeMO (registered trademark) or the combined charging system "Combined Charging System". As a charging device, a charging station set up in a commercial facility or a home power supply can also be used. For example, by supplying power from the outside using plug-in technology, the power storage device installed in the automobile 2001 can be charged. Charging can be performed by converting AC power into DC power using a conversion device such as an ACDC converter.

[0259] In addition, although not shown in the figure, the power receiving device can also be installed in the vehicle and the power can be supplied non-contactly from the power transmission device on the ground for charging. When the non-contact power supply method is used, by assembling the power transmission device in the road or the outer wall, charging can be performed not only when the vehicle is parked but also when it is driving. In addition, the non-contact power supply method can also be used to send and receive power between two vehicles. Furthermore, a solar cell can be set on the outside of the vehicle to charge the secondary battery when it is parked or driving. As the supply of power using the above-mentioned non-contact method, an electromagnetic induction method or a magnetic field resonance method can be used.

[0260] exist Fig. 17B In the example of a transport vehicle, a large transport vehicle 2002 including an electrically controlled engine is shown. The transport vehicle 2002 has a power storage module, for example, in which four secondary batteries with a nominal voltage of 3.0 V or more and 5.0 V or less are used as battery cells, and 48 cells are connected in series to form a power storage module with a maximum voltage of 170 V. The battery pack 2201 has the same characteristics as the battery pack 2201 except for the difference in the number of secondary batteries constituting the power storage module. Fig.17A The functions are the same, so the description is omitted.

[0261] exist Fig. 17C In the example, a large transport vehicle 2003 including an engine controlled by electricity is shown. The power storage module 2202 of the transport vehicle 2003 is, for example, a power storage module having a maximum voltage of 600 V, in which one hundred or more secondary batteries having a nominal voltage of 3.0 V or more and 5.0 V or less are connected in series. Therefore, secondary batteries with small variations in characteristics are required.

[0262] exist Fig.17D , an aerial vehicle 2004 including an engine burning fuel is shown as an example. Fig.17D The aircraft 2004 shown includes wheels for taking off and landing, so it can be said that the aircraft 2004 is a type of transportation vehicle. In the aircraft 2004, multiple secondary batteries are connected to form a storage module and include a battery pack 2203 having a storage module and a charging control device.

[0263] The power storage module of the aircraft 2004 has, for example, eight 4V secondary batteries connected in series and a maximum voltage of 32V. In addition to the number of secondary batteries constituting the power storage module, the battery pack 2203 has the same Fig.17A The functions are the same, so the description is omitted.

[0264] Fig.17E As an example, an artificial satellite 2005 including a secondary battery 2204 is shown. Since the artificial satellite 2005 is used in the extremely low temperature space, it is preferable to include a secondary battery 2204 of one embodiment of the present invention having good low temperature resistance. In addition, it is more preferable that the secondary battery 2204 is installed inside the artificial satellite 2005 in a state covered by a heat-insulating member.

[0265] The structure, method, and the like described in this embodiment can be used in combination with the structure, method, and the like described in other embodiments as appropriate.

[0266] (Implementation 5) In this embodiment, refer to Fig.18A and Fig.18BAn example in which a secondary battery according to one embodiment of the present invention is installed in a building will be described. The secondary battery and the control circuit described in this embodiment can use the structure of the power storage device 1000 described in Embodiment 1.

[0267] Fig.18A The house shown includes a storage device 2612 having a secondary battery of one embodiment of the present invention and a solar panel 2610. The storage device 2612 is electrically connected to the solar panel 2610 through wiring 2611 or the like. In addition, the storage device 2612 may also be electrically connected to a charging device 2604 set on the ground. The power obtained by the solar panel 2610 can be charged into the storage device 2612. In addition, the power stored in the storage device 2612 can be charged into the secondary battery included in the vehicle 2603 through the charging device 2604. The storage device 2612 is preferably arranged in the underfloor space portion. By being arranged in the underfloor space portion, the space on the floor can be effectively utilized. Alternatively, the storage device 2612 may also be arranged on the floor.

[0268] The power stored in the power storage device 2612 can also be supplied to other electronic devices in the house. Therefore, even when power cannot be supplied from a commercial power source due to a power outage or the like, the electronic devices can be used by using the power storage device 2612 of one embodiment of the present invention as an uninterruptible power supply.

[0269] Fig.18B An example of a power storage device according to one embodiment of the present invention is shown below. Fig.18B As shown, a power storage device 791 according to one embodiment of the present invention is installed in an underfloor space 796 of a building 799 .

[0270] The power storage device 791 is provided with a control device 790 , and the control device 790 is electrically connected to the switchboard 703 , the power storage controller 705 (also referred to as a control device), the display 706 , and the router 709 through wiring.

[0271] Power is supplied from commercial power supply 701 to switchboard 703 through lead-in installation 710. Power is also supplied from power storage device 791 and commercial power supply 701 to switchboard 703, which supplies the supplied power to general load 707 and power storage load 708 through sockets (not shown).

[0272] Examples of the general load 707 include electronic devices such as a television and a personal computer, and examples of the power storage load 708 include electronic devices such as a microwave oven, a refrigerator, and an air conditioner.

[0273] The power storage controller 705 has a measuring unit 711, a predicting unit 712, and a planning unit 713. The measuring unit 711 has a function of measuring the power consumption of the general load 707 and the power storage load 708 in a day (e.g., from 0:00 to 24:00). In addition, the measuring unit 711 may also have a function of measuring the power of the power storage device 791 and the power supplied from the commercial power supply 701. In addition, the predicting unit 712 has a function of predicting the required power consumed by the general load 707 and the power storage load 708 in the next day based on the power consumption of the general load 707 and the power storage load 708 in a day. In addition, the planning unit 713 has a function of formulating a charge and discharge plan for the power storage device 791 based on the required power predicted by the predicting unit 712.

[0274] The amount of power consumed by the general load 707 and the power storage load 708 measured by the measuring unit 711 can be confirmed using the display 706. Alternatively, it can be confirmed using an electronic device such as a TV or a personal computer through the router 709. Furthermore, it can be confirmed using a portable electronic terminal such as a smart phone or a tablet terminal through the router 709. In addition, the required power for each time period (or each hour) predicted by the prediction unit 712 can be confirmed using the display 706, an electronic device, or a portable electronic terminal.

[0275] The structure, method, and the like described in this embodiment mode can be used in combination with the structure, method, and the like described in other embodiment modes as appropriate.

[0276] (Implementation method 6) In this embodiment, as an example of installing a secondary battery in a vehicle, an example of installing a lithium ion battery of one embodiment of the present invention in a two-wheeled vehicle or a bicycle is shown. In the secondary battery and the control circuit described in this embodiment, the structure of the power storage device 1000 described in Embodiment 1 can be used.

[0277] Fig.19A An example of an electric bicycle using the power storage device according to one embodiment of the present invention will be described. Fig.19A The electric bicycle 8700 shown can use the power storage device of one embodiment of the present invention. For example, the power storage device of one embodiment of the present invention includes a plurality of storage batteries and a protection circuit.

[0278] The electric bicycle 8700 includes a power storage device 8702. The power storage device 8702 supplies power to a motor that assists the rider. In addition, the power storage device 8702 is portable. Fig.19BThe power storage device 8702 taken out of the bicycle is shown. The power storage device 8702 has a plurality of storage batteries 8701 included in the power storage device of one embodiment of the present invention built in, and the remaining power can be displayed on the display unit 8703. In addition, the power storage device 8702 includes the control circuit 8704 shown in Embodiment 6 that can perform charging control or abnormality detection of the secondary battery. The control circuit 8704 is electrically connected to the positive and negative electrodes of the storage battery 8701.

[0279] Fig.19C This is an example of a two-wheeled vehicle using the power storage device of one embodiment of the present invention. Fig.19C The illustrated scooter 8600 includes a power storage device 8602, a side mirror 8601, and a turn signal lamp 8603. The power storage device 8602 can supply power to the turn signal lamp 8603.

[0280] In addition, Fig.19C In the illustrated scooter 8600, the power storage device 8602 can be stored in the under-seat storage portion 8604. Even if the under-seat storage portion 8604 is small, the power storage device 8602 can be stored in the under-seat storage portion 8604.

[0281] The structure, method, and the like described in this embodiment can be used in combination with the structure, method, and the like described in other embodiments as appropriate.

[0282] (Implementation 7) In this embodiment, an example of installing a secondary battery of one embodiment of the present invention in an electronic device is described. As an electronic device equipped with a secondary battery, for example, a television device (also referred to as a television or a television receiver), a display for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone (also referred to as a mobile phone, a mobile phone device), a portable game console, a portable information terminal, a sound reproduction device, a large-scale game console such as a pinball machine, etc. can be cited. As a portable information terminal, a notebook personal computer, a tablet terminal, an e-book terminal, a mobile phone, etc. can be cited. In the secondary battery and the control circuit described in this embodiment, the structure of the power storage device 1000 described in Embodiment 1 can be used.

[0283] Fig. 20A The mobile phone 2100 includes, in addition to a display portion 2102 incorporated in a housing 2101 , operation buttons 2103 , an external connection port 2104 , a speaker 2105 , a microphone 2106 , and the like. The mobile phone 2100 also includes a secondary battery 2107 .

[0284] The mobile phone 2100 can execute various application programs such as mobile phone, e-mail, article reading and writing, music playing, network communication, computer games, etc.

[0285] In addition to time setting, the operation button 2103 may have various functions such as power switch, wireless communication switch, silent mode setting and cancellation, power saving mode setting and cancellation, etc. For example, by using the operating system incorporated in the mobile phone 2100, the function of the operation button 2103 can be freely set.

[0286] In addition, the mobile phone 2100 can perform short-range wireless communication standardized by the communication system. For example, by communicating with a headset capable of wireless communication, a hands-free call can be made.

[0287] In addition, the mobile phone 2100 has an external connection port 2104, and data can be directly sent to or received from other information terminals through a connector. In addition, charging can also be performed through the external connection port 2104. In addition, the charging operation can also be performed using wireless power supply without using the external connection port 2104.

[0288] Furthermore, the mobile phone 2100 preferably includes a sensor. For example, a fingerprint sensor, a pulse sensor, a body sensor such as a temperature sensor, a touch sensor, a pressure sensor, or an acceleration sensor may be preferably installed as the sensor.

[0289] Fig. 20B An unmanned aerial vehicle 2300 including a plurality of rotors 2302 is shown. The unmanned aerial vehicle 2300 is also called a drone. The unmanned aerial vehicle 2300 includes a secondary battery 2301 of one embodiment of the present invention, a camera 2303, and an antenna (not shown). The unmanned aerial vehicle 2300 can be remotely operated via the antenna.

[0290] Fig. 20C An example of a robot is shown. Fig. 20C The robot 6400 shown includes a secondary battery 6409, an illumination sensor 6401, a microphone 6402, an upper camera 6403, a speaker 6404, a display unit 6405, a lower camera 6406, an obstacle sensor 6407, a moving mechanism 6408, a computing device, and the like.

[0291] The microphone 6402 has a function of detecting the user's voice and surrounding sounds, etc. In addition, the speaker 6404 has a function of emitting sound. The robot 6400 can communicate with the user through the microphone 6402 and the speaker 6404.

[0292] The display unit 6405 has the function of displaying various information. The robot 6400 can display the information required by the user on the display unit 6405. The display unit 6405 can also be equipped with a touch panel. In addition, the display unit 6405 can be a detachable information terminal, and by setting it at a fixed position of the robot 6400, it can be charged and send and receive data.

[0293] The upper camera 6403 and the lower camera 6406 have the function of photographing the surrounding environment of the robot 6400. In addition, the obstacle sensor 6407 can detect whether there is an obstacle in the direction of the robot 6400 when it moves forward using the moving mechanism 6408. The robot 6400 can confirm the surrounding environment using the upper camera 6403, the lower camera 6406, and the obstacle sensor 6407 and move safely.

[0294] The robot 6400 is provided with a secondary battery 6409 according to one embodiment of the present invention and a semiconductor device or an electronic component therein.

[0295] Fig.20D An example of a sweeping robot is shown. The sweeping robot 6300 includes a display unit 6302 disposed on the top surface of a frame 6301, a plurality of cameras 6303 disposed on the side, a brush 6304, an operation button 6305, a secondary battery 6306, various sensors, etc. Although not shown in the figure, the sweeping robot 6300 also has wheels, a suction port, etc. The sweeping robot 6300 can walk by itself and can detect garbage 6310, and can suck the garbage from the suction port set below.

[0296] The cleaning robot 6300 can determine whether there are obstacles such as walls, furniture, or steps by analyzing the image captured by the camera 6303. In addition, when an object such as a wire that may be entangled with the brush 6304 is found through image analysis, the rotation of the brush 6304 can be stopped. The internal area of ​​the cleaning robot 6300 is equipped with a secondary battery 6306 and a semiconductor device or an electronic component according to one embodiment of the present invention.

[0297] Fig.21A An example of a wearable device is shown. A secondary battery is used as a power source of the wearable device. In addition, in order to improve the splash-proof, waterproof or dust-proof performance when the user uses the wearable device in daily life or outdoors, the user not only wants the wearable device to be able to be charged by wire with the connector part exposed for connection, but also wants to be able to be charged wirelessly.

[0298] For example, the secondary battery of one embodiment of the present invention can be installed in Fig.21AThe spectacles-type device 4000 shown in FIG. 4 includes a frame 4000a and a display unit 4000b. By installing a secondary battery in the temple of the curved frame 4000a, the spectacles-type device 4000 can be lightweight, well-balanced, and used continuously for a long time.

[0299] The secondary battery of one embodiment of the present invention may be mounted on the earphone type device 4001. The earphone type device 4001 includes at least a microphone unit 4001a, a flexible tube 4001b, and an earphone unit 4001c. The secondary battery may be provided in the flexible tube 4001b or in the earphone unit 4001c.

[0300] In addition, the secondary battery of one embodiment of the present invention may be mounted on the device 4002 that can be directly mounted on the body. In addition, the secondary battery 4002b may be provided in the thin housing 4002a of the device 4002.

[0301] In addition, the secondary battery of one embodiment of the present invention may be mounted on the device 4003 that can be mounted on clothing. In addition, the secondary battery 4003 b may be provided in the thin housing 4003 a of the device 4003 .

[0302] In addition, the secondary battery of one embodiment of the present invention may be mounted on a waistband device 4006. The waistband device 4006 includes a waistband portion 4006a and a wireless power supply and reception portion 4006b, and the secondary battery may be mounted in an inner region of the waistband portion 4006a.

[0303] In addition, the secondary battery of one embodiment of the present invention can be mounted on a watch-type device 4005. The watch-type device 4005 includes a display portion 4005a and a strap portion 4005b, and the secondary battery can be mounted on the display portion 4005a or the strap portion 4005b.

[0304] The display unit 4005a can display various information such as e-mails and incoming phone calls in addition to the time.

[0305] In addition, since the watch-type device 4005 is a wearable device that is directly wrapped around the wrist, it can also be equipped with sensors for measuring the user's pulse, blood pressure, etc. Thus, the user's exercise volume and health-related data can be stored for health management.

[0306] Fig. 21B is a perspective view showing the watch-type device 4005 taken off from the wrist.

[0307] in addition, Fig. 21C It is a side view. Fig. 21CThe internal region includes a secondary battery 913. The secondary battery 913 is the secondary battery described in Embodiment 3. The secondary battery 913 is provided at a position overlapping with the display portion 4005a, and high density and high capacity can be achieved, so the secondary battery 913 is small and lightweight.

[0308] The structure, method, and the like described in this embodiment mode can be used in combination with the structure, method, and the like described in other embodiment modes as appropriate. [Explanation of symbols]

[0309] 10: Battery, 15: Control circuit, 34: Current detection element, 36: FET, 37: FET, 41: Resistor, 51: External terminal, 52: External terminal, 200A: Terminal, 200B: Terminal, 200C: Terminal, 200D: Terminal, 202A: Transistor, 202B: Transistor, 203A: Diode, 203B: Diode, 204A: Terminal, 204B: Terminal, 205A: Terminal, 205B: Terminal, 206A: Terminal, 206B: Terminal, 300: Secondary battery, 301: Positive electrode can, 302: Negative electrode can, 303: Gasket, 304: Positive electrode, 305: Positive electrode current collector, 306: Positive electrode active material layer, 307: Negative electrode, 308: Negative electrode current collector, 309: negative electrode active material layer, 310: separator, 312: gasket, 322: spacer, 500: secondary battery, 501: positive electrode current collector, 502: positive electrode active material layer, 503: positive electrode, 504: negative electrode current collector, 505: negative electrode active material layer, 506: negative electrode, 507: separator, 509: outer packaging body, 510: positive electrode lead electrode, 511: negative electrode lead electrode, 513: secondary battery, 514: terminal, 515: sealing tape, 517: antenna, 519: layer, 529: label, 531: secondary battery pack, 540: circuit board, 552: other side, 590a: circuit system, 590b: circuit system, 590: control circuit, 601 : Positive electrode cap, 602: Battery can, 603: Positive electrode terminal, 604: Positive electrode, 605: Separator, 606: Negative electrode, 607: Negative electrode terminal, 608: Insulating plate, 609: Insulating plate, 611: PTC element, 613: Safety valve mechanism, 614A: Conductive plate, 614B: Conductive plate, 614: Conductive plate, 615: Storage module, 616: Secondary battery, 620: Control circuit, 621: Wiring, 622: Wiring, 623: Wiring, 624: Conductor, 625: Conductor, 626: Wiring, 627: Wiring, 628A: Conductive plate, 628B: Conductive plate, 628: Conductive plate, 629: External terminal, 630: External terminal, 701: Commercial power supply, 70 3: switchboard, 705: power storage controller, 706: display, 707: general load, 708: power storage load, 709: router, 710: lead-in installation unit, 711: measurement unit, 712: prediction unit, 713: planning unit, 790: control device, 791: power storage device, 796: underfloor space unit, 799: building, 911a: terminal, 911b: terminal, 913: secondary battery, 930a: frame, 930b: frame, 930: frame, 931a: negative electrode active material layer, 931: negative electrode, 932a: positive electrode active material layer, 932: positive electrode, 933: separator, 950a: winding body, 950: winding body, 951: terminal, 952: terminal,1000: power storage device, 1300: rectangular secondary battery, 1301a: first power storage device, 1301b: first power storage device, 1302: battery controller, 1303: engine controller, 1304: engine, 1305: transmission, 1306: DCDC converter, 1307: electric power steering system, 1308: heater, 1309: defogger, 1310: DCDC circuit, 1311: second power storage device, 1312: inverter, 1313: audio, 1314: power window, 1315: lamp, 1316: tire, 1317: rear engine, 1320: control circuit unit, 1321: control circuit unit, 1322: control circuit, 1324: switch portion, 1325: external connection terminal, 1326: external connection terminal, 1332: PTC element, 1413: fixing portion, 1414: fixing portion, 1415: power storage module, 1421: wiring, 1422: wiring, 2001: automobile, 2002: transport vehicle, 2003: transport vehicle, 2004: aircraft, 2005: artificial satellite, 2100: mobile phone, 2101: housing, 2102: display portion, 2103: operation button, 2104: external connection port, 2105: speaker, 2106: microphone, 2107: secondary battery, 2200: battery pack, 2201: battery pack, 2203: battery pack, 2204: secondary battery, 2300: Unmanned aerial vehicle, 2301: secondary battery, 2302: rotor, 2303: camera, 2603: vehicle, 2604: charging device, 2610: solar panel, 2611: wiring, 2612: power storage device, 4000a: frame, 4000b: display unit, 4000: glasses type device, 4001a: microphone unit, 4001b: flexible tube, 4001c: earphone unit, 4001: earphone type device, 4002a: frame, 4002b: secondary battery, 4002: device, 4003a: frame, 4003b: secondary battery, 4003: device, 4005a: display unit, 4005b: belt unit, 4005: watch type device, 4006a: belt unit, 4006b: wireless power supply and receiving unit, 4006: belt-type device, 6300: cleaning robot, 6301: housing, 6302: display unit, 6303: camera, 6304: brush, 6305: operation button, 6306: secondary battery, 6310: garbage, 6400: robot, 6401: illumination sensor, 6402: microphone, 6403: upper camera, 6404: speaker, 6405: display unit, 6406: lower camera, 6407: obstacle sensor, 6408: moving mechanism, 6409: secondary battery, 8600: small motorcycle, 8601: side mirror, 8602: power storage device, 8603: turn signal, 8604: under-seat storage unit,8700: electric bicycle, 8701: storage battery, 8702: storage device, 8703: display unit, 8704: control circuit,

Claims

1. A method comprising Li in the positive electrode x Method for charging a battery containing a positive electrode active material represented by MO2, in, The M is one or more selected from Co, Ni, Mn and Al, determining whether first charging is required according to the x value at the start of charging of the battery, When it is determined that the first charging is needed, after the first charging, the second charging and the third charging are sequentially performed, When it is determined that the first charging is not needed, the second charging and the third charging are performed in sequence. In the first charging, the current value is greater than 1C and less than 5C and the charging time is greater than 10 seconds and less than 30 seconds, The second charging is constant current charging, Furthermore, the third charging is constant voltage charging.

2. The battery charging method according to claim 1, When the x value is within a range of 0.80 to 1.0, it is determined that the first charging is required.

3. The battery charging method according to claim 1, When the x value is within a range of 0.40 to 0.60, it is determined that the first charging is required.

4. The battery charging method according to claim 1, When the x value is within a range of 0.80 to 1.0 or within a range of 0.40 to 0.60, it is determined that the first charging is required.

5. A method for charging a battery according to any one of claims 1 to 4, Wherein whether the first discharge is required is determined according to the x value at the beginning of charging of the battery, When it is determined that the first discharge is needed, the second charge and the third charge are sequentially performed after the first discharge. When it is determined that the first discharge is not necessary, the second charge and the third charge are performed in sequence. The first discharge has a current value of not less than 1C and not more than 5C, and a discharge time of not less than 10 seconds and not more than 30 seconds.

6. The battery charging method according to claim 5, When the x value is within a range of 0.15 to 0.20, it is determined that the first discharge is required.

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