Negative electrode material, laminate, and battery

Abstract

A battery provided with a negative electrode having a negative electrode active material layer and a solid electrolyte layer in contact with the negative electrode active material layer, the negative electrode active material layer containing a negative electrode active material that absorbs or desorbs ions of an alkali metal when the alkali metal is used as a counter electrode and 0.1 V or more is applied. Either or both of the negative electrode active material layer and the solid electrolyte layer contain a polymer having the ability to preferentially conduct metal ions.

Description

Technical Field

[0001] The present invention relates to a negative electrode material, a laminate, and a battery.

[0002] This application claims priority based on Japanese Patent Application No. 2022-177446 filed on November 4, 2022, and incorporates its content herein. Background Art

[0003] In a battery such as a lithium-ion battery, an electrolyte having metal ion conductivity is disposed between a positive electrode active material and a negative electrode active material. Each active material exchanges metal ions through the electrolyte to perform charging or discharging. As such an electrolyte, research on a solid electrolyte with high safety and easy handling has been conducted (for example, refer to Patent Documents 1 and 2).

[0004] Since the solid electrolyte has a higher hardness than the conventionally known electrolytic solution, it is possible to suppress the growth of lithium dendrites that may occur in the negative electrode active material. Therefore, a battery using a solid electrolyte is expected to improve the durability of the battery.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Chinese Patent Application Specification No. 112448100

[0008] Patent Document 2: Chinese Patent Application Specification No. 110247111 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] On the other hand, in conventional batteries, there is still room for improvement in the peripheral structure of the negative electrode active material in order to improve the performance of lithium secondary batteries.

[0011] For example, in the negative electrode, the negative electrode active material, a binder, and a conductive material together form a negative electrode active material layer, and metal ions are exchanged through a material in contact with the negative electrode active material such as a binder. However, the transference number of metal ions in conventional binders is not sufficient. The "transference number of metal ions" means "the ratio of the amount of moving metal ions to the total amount of all ion species moving in the system".

[0012] In addition, in order to increase the transference number of metal ions in the negative electrode active material layer, research has also been conducted on using a solid electrolyte in combination. However, although the conventionally known solid electrolyte has excellent ionic conductivity and safety, on the other hand, due to its rigidity, poor contact is likely to occur at the interface with the negative electrode active material.

[0013] The present invention has been made in view of such circumstances, and an object thereof is to provide a battery that ensures a good ion conduction state with a negative electrode active material and has high durability. Further, an object is to provide a negative electrode material and a laminate that can easily ensure a good ion conduction state with the negative electrode active material.

[0014] Means for Solving the Problems

[0015] In order to solve the above problems, one aspect of the present invention includes the following aspects.

[0016] [1] A battery comprising a negative electrode having a negative electrode active material layer and a solid electrolyte layer in contact with the negative electrode active material layer, the negative electrode active material layer containing a negative electrode active material that intercalates or deintercalates ions of an alkali metal when an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied, and either or both of the negative electrode active material layer and the solid electrolyte layer containing a polymer having the ability to preferentially conduct metal ions.

[0017] [2] The battery according to [1], wherein both the negative electrode active material layer and the solid electrolyte layer contain the polymer.

[0018] [3] The battery according to [1] or [2], wherein the negative electrode active material is a phosphorus-carbon composite material containing a phosphorus atom and a carbon atom.

[0019] [4] The battery according to [3], wherein the content rate of phosphorus atoms in the phosphorus-carbon composite material is 10% by mass or more and 95% by mass or less, the content rate of carbon atoms in the phosphorus-carbon composite material is 5% by mass or more and 90% by mass or less, and the weight reduction rate WL at a measurement temperature of 620 °C obtained by thermogravimetric measurement under the following conditions 620 and the weight reduction rate WL at a measurement temperature of 780 °C 780 The ratio WL 620 / WL 780 is 0.1 or more and 0.9 or less.

[0020] (Thermogravimetric measurement) Accurately weigh 10 mg of the phosphorus-carbon composite material as a sample, and using a thermogravimetric measurement device, measure the weight change when heating from 50 °C to 780 °C at a heating rate of 10 °C / minute in a nitrogen gas stream.

[0021] (Weight reduction rate) The ratio of the weight of the sample at the measurement temperature to the weight of the accurately weighed sample is defined as the weight reduction rate (weight %) at the measurement temperature.

[0022] [5] The battery according to [4], wherein the weight reduction rate WL at a measurement temperature of 300 °C obtained by the above thermogravimetric measurement 300The ratio WL 600 of WL 300 / WL 600 is not less than -0.1 and not more than 0.1.

[0023] [6] The battery according to [4] or [5], wherein in the XPS spectrum, there is a peak representing the bond between a phosphorus atom and a carbon atom.

[0024] [7] The battery according to any one of [4] to [6], wherein in the XRD pattern measured using CuKα radiation, the intensity I at 2θ = 20°, 20 the intensity I at 2θ = 26.3°, 26.3 and the intensity I at 2θ = 40° 40 satisfy the following formulas (1) to (3).

[0025] |P| / |B| < 2 (1)

[0026] P = I 26.3 - I 40 (2)

[0027] B = (I 20 - I 40 ) × (26.3 - 40) / (20 - 40) (3)

[0028] [8] The battery according to any one of [4] to [7], which has a nuclear particle containing a phosphorus atom and a carbon film covering the surface of the nuclear particle.

[0029] [9] The battery according to any one of [1] to [8], wherein the polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capturing ability.

[0030]

[10] The battery according to [9], wherein the anionic functional group has at least one of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, a conjugated anion of a carboxylic acid group, and a conjugated anion of a phenolic hydroxyl group.

[0031]

[11] The battery according to [9] or

[10] , wherein the functional group having an anion capturing ability has Lewis acidity.

[0032]

[12] A negative electrode material, which contains a negative electrode active material and a polymer having the ability to preferentially conduct metal ions, and the negative electrode active material embeds or de-embeds ions of the alkali metal when using the alkali metal as a counter electrode and applying a voltage of 0.1 V or more.

[0033]

[13] A laminate includes a negative electrode having a negative electrode active material layer and a solid electrolyte layer in contact with the negative electrode active material layer. The solid electrolyte layer contains a polymer having the ability to preferentially conduct metal ions. When an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied, the alkali metal ions are intercalated into or deintercalated from the negative electrode active material contained in the negative electrode active material layer.

[0034] Advantages of the Invention

[0035] According to the present invention, it is possible to provide a battery that ensures a good ion conduction state with the negative electrode active material and has high durability. In addition, it is possible to provide a negative electrode material and a laminate that can easily ensure a good ion conduction state with the negative electrode active material. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram showing a all-solid-state lithium secondary battery as an example of a battery.

[0037] Figure 2 It is a graph showing the results of thermogravimetric measurement of a P-C material and a P-C mixture.

[0038] Figure 3 It is an XPS spectrum of a P-C material and a P-C mixture.

[0039] Figure 4 It is a transmission electron microscope (TEM) photograph of a P-C material.

[0040] Figure 5 It is an XRD pattern of a P-C material and a P-C mixture.

[0041] Figure 6 It is a charge-discharge curve showing the results of the charge-discharge test of Example 1.

[0042] Figure 7 It is a charge-discharge curve showing the results of the charge-discharge test of Comparative Example 1.

[0043] Figure 8 It is a graph showing the charge-discharge cycle characteristics of Example 1 and Comparative Example 1.

[0044] Figure 9 It is a charge-discharge curve showing the results of the charge-discharge test of Example 2 and Comparative Example 2. DETAILED DESCRIPTION

[0045] Hereinafter, with reference to Figures 1 to 5 The battery, negative electrode material, and laminate of the present embodiment will be described. It should be noted that in all the following drawings, for easy observation of the drawings, the dimensions, ratios, etc. of each component are appropriately different.

[0046] "Battery, Laminate"

[0047] The battery of this embodiment includes a positive electrode, a negative electrode having a negative electrode active material layer, and a solid electrolyte layer disposed between the positive electrode and the negative electrode. The solid electrolyte layer is in contact with the negative electrode active material layer. Hereinafter, the description will be given in sequence.

[0048] Figure 1 It is a schematic diagram showing a fully solid-state lithium secondary battery as an example of a battery. Figure 1 The fully solid-state lithium secondary battery 1000 shown in has a laminate 100 having a positive electrode 110, a negative electrode 120, and a solid electrolyte layer 130, and an outer package 200 that houses the laminate 100. In addition, the fully solid-state lithium secondary battery 1000 may also have a bipolar structure in which a positive electrode active material and a negative electrode active material are disposed on both sides of a current collector. As a specific example of the bipolar structure, for example, the structure described in JP-A-2004-95400 can be cited.

[0049] The positive electrode 110 has a positive electrode active material layer 111 and a positive electrode current collector 112. The positive electrode active material layer 111 contains a positive electrode active material and a solid electrolyte. In addition, the positive electrode active material layer 111 may also contain a conductive material and a binder.

[0050] The negative electrode 120 has a negative electrode active material layer 121 and a negative electrode current collector 122. The negative electrode active material layer 121 contains a negative electrode active material. In addition, the negative electrode active material layer 121 may also contain a solid electrolyte and a conductive material.

[0051] The laminate 100 may also have an external terminal 113 connected to the positive electrode current collector 112 and an external terminal 123 connected to the negative electrode current collector 122. In addition, the fully solid-state lithium secondary battery 1000 may also have a separator between the positive electrode 110 and the negative electrode 120.

[0052] The fully solid-state lithium secondary battery 1000 further includes an insulator (not shown) that insulates the laminate 100 from the outer package 200 and a sealant (not shown) that seals the opening 200a of the outer package 200.

[0053] The outer package 200 may be a container formed by shaping a highly corrosion-resistant metal material such as aluminum, stainless steel, or nickel-plated steel. In addition, as the outer package 200, a container obtained by processing a laminated film having corrosion-resistant processing on at least one surface into a bag shape may also be used.

[0054] As the shape of the fully solid-state lithium secondary battery 1000, for example, coin type, button type, paper type (or sheet type), cylindrical type, square type, or laminated type (pouch type) and other shapes can be cited.

[0055] The illustration of the all-solid-state lithium secondary battery 1000 shows an example of a configuration having one laminate 100, but the present embodiment is not limited thereto. The all-solid-state lithium secondary battery 1000 may also have a configuration in which the laminate 100 is used as a unit cell and a plurality of unit cells (laminates 100) are enclosed inside the outer package 200.

[0056] For the all-solid-state lithium secondary battery, for example, the configurations, materials, and manufacturing methods described in

[0141] to

[0181] of WO2022 / 113904A1 can be used.

[0057] <Active material>

[0058] As the positive electrode active material, for example, a lithium-containing composite metal oxide containing lithium (Li) and at least one transition metal selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, Cu, and Al can be cited. As such a lithium composite metal oxide, for example, LiCoO 2 、LiNiO 2 、LiMnO 2 O 4 、Li 2 MnO 3 、LiNi x Mn y Co 1-x-y O 2 [0 < x + y < 1], LiNi x Co y Al 1-x-y O 2 [0 < x + y < 1], LiCr 0.5 Mn 0.5 O 2 、LiFePO 4 、Li 2 FeP 2 O 7 、LiMnPO 4 、LiFeBO 3 、Li 3 V 2 (PO 4 ) 3 、Li 2 CuO 2 、Li 2 FeSiO 4 、Li 2 MnSiO 4 etc.

[0059] The negative electrode of the lithium ion battery is not particularly limited, and it may also be a negative electrode containing a negative electrode active material that uses lithium as a counter electrode and can intercalate or deintercalate lithium ions when a voltage of 0.1 V or more is applied, and optionally contains a conductive assistant, a binder, and the like. Examples include simple substances of elements such as Li, Si, P, Sn, Si-Mn, Si-Co, Si-Ni, In, and Au, alloys or composites containing these elements, carbon materials such as graphite, and substances obtained by intercalating lithium ions between the layers of the carbon material.

[0060] A negative electrode active material having an average charging potential of 0.1 V or more with respect to the charging capacity (mAh / g) when charging at a charging rate of 0.2 C using lithium metal as a counter electrode can be used as the negative electrode active material contained in the negative electrode of the lithium ion battery of the present embodiment.

[0061] <Phosphorus-carbon composite material>

[0062] Furthermore, as the negative electrode active material, a phosphorus-carbon composite material containing phosphorus atoms and carbon atoms is preferable. In the following description, the "phosphorus-carbon composite material" is sometimes abbreviated as "P-C material".

[0063] Regarding the P-C material, the content rate of phosphorus atoms in the P-C material is 10% by mass or more and 95% by mass or less. In addition, the content rate of carbon atoms in the P-C material is 5% by mass or more and 90% by mass or less. When the P-C material is composed of phosphorus atoms and carbon atoms, the total of the content rate of carbon atoms and the content rate of phosphorus atoms in the P-C material is 100% by mass. It should be noted that even when the P-C material is composed of carbon atoms and phosphorus atoms, impurities inevitably mixed in from the raw materials and manufacturing processes of the P-C material are allowed.

[0064] 60% by mass or more of the entire P-C material may be composed of phosphorus atoms and carbon atoms, and further contain elements other than phosphorus atoms and carbon atoms.

[0065] Examples of elements other than phosphorus atoms and carbon atoms contained in the P-C material include lithium, silicon, germanium, tin, aluminum, zinc, magnesium, transition metals, nitrogen, oxygen, fluorine, silicon, titanium, niobium, sulfur, and chlorine. They can use metal oxides, composite metal oxides, metal fluorides, metal sulfides, metal chlorides, silicon oxides, silicates, titanates, and aluminates as raw materials.

[0066] The content rate of phosphorus atoms, the content rate of carbon atoms, and the content rate of other atoms that can be further contained in the P-C material can be determined by known ICP analysis.

[0067] In the P-C material, the content rate of the above-mentioned phosphorus atoms is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more. When the content rate of phosphorus is high, the initial charge-discharge capacity of the P-C material can be improved. In addition, in the P-C material, the content rate of the above-mentioned phosphorus atoms is preferably 90% by mass or less, more preferably 80% by mass or less, and still more preferably 75% by mass or less. Because if the content rate of phosphorus atoms is too high, the cycle characteristics of the P-C material will decrease. The upper limit value and the lower limit value of the content rate of phosphorus atoms can be arbitrarily combined.

[0068] In the P-C material, the content rate of the above-mentioned carbon atoms is preferably 10% by mass or more, more preferably 20% by mass or more, and still more preferably 25% by mass or more. When the content rate of carbon atoms is high, the cycle characteristics of the P-C material can be improved. In addition, in the P-C material, the content rate of the above-mentioned carbon atoms is preferably 80% by mass or less, more preferably 70% by mass or less, and still more preferably 50% by mass or less. Because if the content rate of carbon atoms is too high, the initial charge-discharge capacity of the P-C material will decrease. The upper limit value and the lower limit value of the content rate of carbon atoms can be arbitrarily combined.

[0069] Although the details will be described below, the P-C material can be manufactured by ball-milling phosphorus and a carbon material. The inventors analyzed and studied the obtained P-C material in detail, and as a result, it was confirmed that the P-C material is not a simple mixture of the raw material phosphorus and the carbon material, but a novel material in which phosphorus atoms and carbon atoms are chemically bonded (covalently bonded), having physical properties different from those of the raw material phosphorus and carbon material.

[0070] Hereinafter, the P-C material and a mixture of phosphorus and a carbon material (hereinafter, sometimes referred to as "P-C mixture") will be compared, and the physical properties of the P-C material will be described in detail.

[0071] In the following description, an example of the P-C material is compared with an example of a mixture obtained by mixing the same raw materials as the P-C material in a mortar. In the examples shown below, in the raw materials of the P-C material and the P-C mixture, black phosphorus and a carbon material are contained in a ratio of 6:4 (mass ratio). In the P-C material and the P-C mixture, CSCNT (cup-stacked carbon nanotube) is used as the carbon material.

[0072] [Behavior with respect to heat]

[0073] The weight reduction rate WL at a measurement temperature of 620 °C obtained by thermogravimetric measurement of the P-C material under the following conditions 620 and the weight reduction rate WL at a measurement temperature of 780 °C 780 The ratio WL 620 / WL 780is 0.1 or more and 0.9 or less.

[0074] (Thermogravimetric measurement)

[0075] Precisely weigh 10 mg of the phosphorus-carbon composite material as a sample, and using a thermogravimetric measurement device, measure the weight change when heating from 50 °C to 780 °C at a heating rate of 10 °C per minute under a nitrogen gas flow.

[0076] (Weight reduction rate)

[0077] Take the ratio of the weight of the sample at the measurement temperature to the weight of the precisely weighed sample as the weight reduction rate (weight %) at the measurement temperature.

[0078] Figure 2 is a graph showing the results obtained by performing the above thermogravimetric measurement on an example of the P-C material and an example of the P-C mixture. Figure 2 In it, the horizontal axis represents the heating temperature (°C), and the vertical axis represents the weight reduction rate (weight %) relative to the weight of the sample. Figure 2 In it, it is a graph where the symbol A represents the behavior of the P-C material and the symbol X represents the behavior of the P-C mixture.

[0079] As Figure 2 shown in 620 ( Figure 2 In it, represented by the symbol X1), the weight reduction rate WL 780 ( Figure 2 In it, represented by the symbol X2) at the measurement temperature of 620 °C and the weight reduction rate WL 620 at the measurement temperature of 780 °C both become lower than 58%. The P-C mixture shows a sharp weight reduction at the measurement temperature of 350 °C to 450 °C, and at 620 °C, about 60% of the weight of the sample disappears from the initial weight. In addition, after the sharp weight reduction at the measurement temperature of 350 °C to 450 °C, basically no weight reduction is seen. As a result, for the P-C mixture, the ratio of WL 780 to WL 620 / WL 780 exceeds 0.9.

[0080] It is considered that the reduced weight corresponds to the weight of black phosphorus as a raw material. For the P-C mixture, it is considered that the black phosphorus contained in the P-C mixture disappears by heating. It is known that black phosphorus changes to red phosphorus as an allotrope by heating to 125 °C. In addition, it is known that red phosphorus sublimes at 416 °C under normal pressure.

[0081] In contrast, the weight reduction rate WL of the P-C material used in the measurement at the measurement temperature of 620 °C 620 (Figure 2 in which, represented by symbol A1, and the weight loss rate WL at the measurement temperature of 780 °C 780 ( Figure 2 in which, represented by symbol A2, the ratio WL 620 / WL 780 is included in the range of 0.1 or more and 0.9 or less.

[0082] In addition, for the P-C material, the weight loss rate WL at the measurement temperature of 300 °C obtained by the above thermogravimetric measurement 300 ( Figure 2 in which, represented by symbol A3, and the weight loss rate WL at the measurement temperature of 600 °C 600 ( Figure 2 in which, represented by symbol A4, the ratio WL 300 / WL 600 is preferably included in the range of -0.1 or more and 0.1 or less.

[0083] That is, different from the P-C mixture, the P-C material has basically no weight loss until the measurement temperature reaches 300 °C and is thermally stable at 300 °C.

[0084] WL 620 / WL 780 is preferably 0.1 or more, more preferably 0.3 or more, and still more preferably 0.5 or more. In addition, WL 620 / WL 780 is preferably 0.9 or less, more preferably 0.8 or less. The upper and lower limit values of WL 620 / WL 780 can be arbitrarily combined.

[0085] WL 300 / WL 600 is preferably -0.1 or more, more preferably -0.08 or more. In addition, WL 300 / WL 600 is preferably 0.1 or less, more preferably 0.08 or less. The upper and lower limit values of WL 300 / WL 600 can be arbitrarily combined.

[0086] From Figure 2 the results shown above, it is considered that for the P-C material, the black phosphorus used as the raw material has changed into a substance that shows different behavior from black phosphorus with respect to heat.

[0087] [Presence or absence of P-C bond]

[0088] The P-C material has peaks in the XPS spectrum that represent the bonds between phosphorus atoms and carbon atoms. It is known that the "peaks representing the bonds between phosphorus atoms and carbon atoms" appear in the range of 132 to 136 eV in the XPS spectrum. It should be noted that in the following description, the bond between a phosphorus atom and a carbon atom is sometimes abbreviated as the "P-C bond".

[0089] Figure 3 is the XPS spectrum of the P-C material and the P-C mixture. Figure 3 In it, the horizontal axis represents the binding energy (eV), and the vertical axis represents the number of detected photoelectrons (cps (count per second)). Figure 3 In it, the symbol A represents the P-C material, and the symbol X represents the P-C mixture.

[0090] (XPS spectrum measurement conditions)

[0091] The XPS spectrum is measured under the following measurement conditions.

[0092] · Measuring equipment: XPS device, ESCA-3400 (manufactured by Shimadzu Corporation)

[0093] · Radiation source: MgKα ray (20 mA, 10 kV)

[0094] When a peak is detected in the range of 132 to 136 eV, it is determined that there is a P-C bond.

[0095] As Figure 3 shown in, it is known that for the P-C mixture, no peak representing the P-C bond is detected in the range of 132 to 136 eV, but for the P-C material, a peak representing the P-C bond (denoted by the symbol α) is detected.

[0096] From Figure 3 the results shown in, it is considered that for the P-C material, it becomes a substance having a chemical bond between a phosphorus atom and a carbon atom.

[0097] [Appearance]

[0098] The P-C material has nuclear particles containing phosphorus atoms and a carbon film covering the surface of the above nuclear particles.

[0099] Figure 4 is a transmission electron microscope (TEM) photograph of the P-C material. As Figure 4 shown in, the particles 50 of the P-C material exhibit a core-shell structure in which the carbon film 52 covers the surface of the nuclear particles 51 containing phosphorus atoms.

[0100] The inclusion of phosphorus atoms and carbon atoms in the P-C material can be confirmed by using EDX (Energy Dispersive X-ray Spectroscopy).

[0101] In addition, when the P-C material consists only of phosphorus atoms and carbon atoms, in the TEM photograph, the heavier atoms, i.e., phosphorus atoms, are photographed more darkly. Therefore, based on the TEM photograph, it can be simply judged that the core particle 51 contains phosphorus atoms and is covered with a carbon film 52 containing carbon atoms, which is a core-shell structure.

[0102] (Imaging conditions for TEM photographs)

[0103] The TEM photograph was taken under the following imaging conditions.

[0104] · TEM device: Transmission electron microscope H-9000NAR (manufactured by Hitachi, Ltd.)

[0105] · Field of view: Maximum 500 nm × 500 nm. At least a part of the particles of the P-C material was placed within the field of view for photography.

[0106] The P-C material preferably has the above core-shell structure in addition to satisfying the above necessary conditions regarding [behavior with respect to heat].[[]END]]

[0107] [Crystalline state]

[0108] Figure 5 is the XRD distribution of the P-C material and the P-C mixture. Figure 5 In it, the horizontal axis represents the diffraction angle (2θ, °), and the vertical axis represents the diffracted X-ray intensity (a.u.: arbitrary unit). Figure 5 In it, the symbol A represents the P-C material, and the symbol X represents the P-C mixture.

[0109] (XRD distribution measurement conditions)

[0110] The XRD distribution was measured under the following measurement conditions.

[0111] · Measuring equipment: Sample horizontal type multifunctional X-ray diffractometer Ultima IV (manufactured by Rigaku Corporation)

[0112] · Radiation source: CuKα ray

[0113] · Measurement range (2θ): 10° to 90°

[0114] · Scanning speed: 4° / minute

[0115] · Sampling: 0.02°

[0116] · Voltage: 40 kV, Current: 40 mA

[0117] As Figure 5 shown in [reference], for the P-C mixture, the carbon material and black phosphorus each have a certain degree of crystallinity, indicating diffraction peaks. In contrast, for the P-C material, no diffraction peaks as seen in the P-C mixture are observed, and only noise can be confirmed throughout the measurement range. That is, from the results shown in [reference], it is considered that for the P-C material, the crystallinity of the carbon material used as the raw material disappears and becomes amorphous, or becomes a fine carbon material where the crystalline state cannot be confirmed. Figure 5 Here, when the XRD distribution of the P-C material is measured under the above conditions, the intensity I at 2θ = 20° in the XRD distribution measured under the above conditions,

[0118] the intensity I at 2θ = 26.3°, and the intensity I at 2θ = 40° satisfy the following relational expressions (1) to (3). 20 the intensity I at 2θ = 26.3°, and 26.3 the intensity I at 2θ = 40° satisfy the following relational expressions (1) to (3). 40 satisfy the following relational expressions (1) to (3).

[0119] |P| / |B| < 2 (1)

[0120] P = I 26.3 - I 40 (2)

[0121] B = (I 20 - I 40 ) × (26.3 - 40) / (20 - 40) (3)

[0122] When measuring the XRD distribution of the carbon material used as the raw material, the peak of the carbon material appears at 2θ = 26.3°, which corresponds to the peak of graphite (002). On the other hand, in the XRD distribution of a normal carbon material, there are no peaks at 2θ = 20° and 2θ = 40°. Thus, in the above formula (1), taking 2θ = 40°, where there is no peak of the carbon material, as the reference point, by comparing the intensity at the reference point in the XRD distribution with the intensity at the position (2θ = 26.3°) where the peak of the raw material carbon material exists, the state of the carbon material can be judged.

[0123] "P" represented by the above formula (2) is the difference between the intensity I at the reference point and the intensity I at the position where the peak of the carbon material exists, indicating the difference from the peak at the reference point. 40 and the intensity I at the position where the peak of the carbon material exists, 26.3 indicating the difference from the peak at the reference point.

[0124] "B" represented by the above formula (3) represents the baseline intensity at 2θ = 26.3° estimated from two positions without peaks (2θ = 20° and 2θ = 40°).

[0125] The ratio of the absolute value of P to the absolute value of B (|P| / |B|) represented by the above formula (1) gives the ratio of the baseline intensity to the peak intensity starting from the reference point. When |P| / |B| is 2 or more, it indicates the presence of a peak of the carbon material.

[0126] On the other hand, when |P| / |B| is less than 2 and satisfies formula (1), it can be judged that the peak of the carbon material shrinks, the crystallinity of the carbon material decreases, and the carbon material becomes amorphous, or a very fine carbon material such that the crystalline state cannot be confirmed. Therefore, the P-C material preferably satisfies the above relational expressions (1) to (3) in addition to satisfying the above necessary conditions regarding [behavior with respect to heat].

[0127] As described above, the P-C material is a novel substance that is different from a mixture obtained by mixing phosphorus (black phosphorus in Figures 2 to 5 ) as a raw material with a carbon material in any one of behavior with respect to heat, bonding state, appearance, and crystalline state.

[0128] <Manufacturing method of phosphorus-carbon composite material>

[0129] As described above, the P-C material can be manufactured by a manufacturing method having a step of compounding a carbon material and phosphorus by a mixing and pulverizing treatment accompanied by compression.

[0130] In the above manufacturing method, as the raw material, i.e., the carbon material, at least one selected from the group consisting of amorphous carbon, graphite, porous carbon, mesocarbon microbeads (MCMB), fullerene, carbon nanotube, graphene, graphene oxide, carbon nitride (C 3 N 4 )), and stacked carbon nanofibers can be used. All of these carbon materials have a graphite structure.

[0131] Examples of the amorphous carbon include carbon black (CB), acetylene black (AB), Ketjen black, hard carbon, and soft carbon.

[0132] Examples of the fullerene include C 60 , C 72 , C 84 , etc.

[0133] Examples of the carbon nanotube include single-walled carbon nanotube (SWCNT), multi-walled carbon nanotube (MWCNT), cup-stacked carbon nanotube (CSCNT), and vapor grown carbon fiber (VGCF). They have a structure extending in the 1-axis direction (one-dimensional structure).

[0134] Graphene, graphene oxide, carbon nitride (C 3N 4 ) The stacked carbon nanofibers have a structure (two-dimensional structure) that expands in the in-plane direction.

[0135] In carbon materials, the ends (edge sites) of the graphite structure are more active than the parts other than the edges. Therefore, it is assumed that most of the P-C bonds are formed at the edge sites of the carbon material. Therefore, from the viewpoint of easy formation of P-C bonds, the carbon material used is preferably a material having many edge sites.

[0136] Examples of carbon materials with many edge sites include CSCNT, Graphite, mesocarbon microbeads (MCMB), graphene, graphene oxide, carbon nitride (C 3 N 4 ) The stacked carbon nanofibers. Among them, as the carbon material, CSCNT is preferred.

[0137] In addition, in the above manufacturing method, as the raw material, i.e., phosphorus, any of the known phosphorus allotropes can be used. Phosphorus is preferably black phosphorus, which is the most chemically stable among the phosphorus allotropes and is a good electrical conductor.

[0138] In the above manufacturing method, the "mixing and grinding treatment accompanied by compression" is a treatment that applies a compressive force to a variety of powder raw materials for mixing and grinding of the raw materials. It is considered that by performing the mixing and grinding treatment accompanied by compression on the carbon material and phosphorus, a strong impact force is applied to the carbon material and phosphorus, thereby mixing and grinding the raw material powder, and at the same time generating a chemical change that cannot be obtained in a normal mixture. As a result, it is considered that as a product, a P-C material can be obtained that forms P-C bonds not present in the raw materials and does not show the crystalline state of P-C seen in the raw materials.

[0139] The "mixing and grinding treatment accompanied by compression" can be carried out until the peaks derived from the raw materials disappear in the XRD distribution of the mixed materials. Or, it can be carried out until the formation of P-C bonds can be confirmed in the XPS energy spectrum of the mixed materials.

[0140] Examples of the processing device (grinder) that can perform the mixing and grinding treatment accompanied by compression include a roller mill, a jet mill, a hammer mill, a needle mill, a disk mill, a rod mill, a ball mill, a vibration mill, an ATRITOR, and a bead mill. In the manufacture of P-C materials, especially considering the ability to perform mixing and grinding simultaneously, a stirring type grinder equipped with a grinding container and a rotating body is preferably used. Examples of the stirring type grinder include a needle mill, a disk mill, a rod mill, a ball mill, a vibration mill, an ATRITOR, and a bead mill.

[0141] Furthermore, as the above-mentioned processing device, from the aspect of being able to apply a strong impact force to the carbon material and phosphorus while mixing and pulverizing the raw material powder, a medium agitation type pulverizer is preferred. As the medium agitation type pulverizer, a ball mill, a vibration mill, an ATRITOR, and a bead mill can be cited. Among them, from the viewpoint of being able to easily control the property conditions, as a particularly preferred pulverizer, a ball mill can be cited.

[0142] It is considered that if mixed using a ball mill, first, the atomization of phosphorus and the decomposition of the carbon material occur, and then P-C bonds are formed. During the mixing process in these ball mills, phosphorus becomes the above-mentioned core particles.

[0143] After that, it is considered that the above-mentioned carbon film is formed around the core particles containing phosphorus atoms, and at the same time, compounding occurs to obtain a P-C material.

[0144] During ball mill mixing, by adjusting the rotation speed of the ball mill device, the amount of the medium (balls) relative to the raw material (Ball powder ratio), and the mixing time, the manufacturing conditions can be controlled. That is, by adjusting conditions such as increasing the rotation speed of the ball mill device, increasing the amount of the medium relative to the raw material, and extending the mixing time, the mixing of phosphorus and the carbon material can be promoted, and it becomes easier to obtain a P-C material. By controlling the above-mentioned manufacturing conditions, the generation of P-C bonds can be easily promoted, and WL 620 / WL 780 A P-C material satisfying 0.1 or more and 0.9 or less is obtained.

[0145] The balls are pulverizing media used for pulverizing metal materials. The diameter of the balls is the average particle diameter of the balls. The balls flow at high speed in the pulverizing container by the rotation of the pulverizing container itself of the pulverizer, and collide with the powder raw material containing the carbon material and phosphorus, thereby being pulverized into particles with a smaller average particle diameter. In the pulverizing process, it is preferable that the pulverizing container and the beads are not excessively worn. Therefore, the shape of the balls is preferably spherical or ellipsoidal.

[0146] The diameter of the balls is preferably larger than the average particle diameter of the pulverized P-C material. By using such balls, a large pulverizing energy can be given to the metal material, so metal particles can be effectively obtained in a short time. On the other hand, if the diameter of the balls is too large, the re-aggregation of the P-C material will be promoted, and a P-C material with a wide particle size distribution will be generated.

[0147] The diameter of the balls is preferably 0.1 to 10 mm, more preferably 1 to 10 mm. When the diameter of the balls is in this range, the generation of P-C bonds can be promoted, and re-aggregation can be suppressed. The diameters of the balls put into the pulverizing container can be uniform or different.

[0148] Examples of the material of the balls include glass, agate, alumina, zirconia, stainless steel, chromium steel, tungsten carbide, silicon carbide, and silicon nitride. Among these, zirconia is preferably used because it has a relatively high hardness and is thus less prone to wear, and also because it has a relatively large specific gravity and can therefore generate a large amount of crushing energy. By using these balls, the raw material powder of the P-C material can be effectively crushed.

[0149] The weight ratio of the balls to the raw material powder of the P-C material is set as the ball-powder ratio. By increasing the ball-powder ratio, a strong impact force can be applied to the raw material powder of the P-C material at a high frequency, and thus the formation of P-C bonds can be further promoted. If the ball-powder ratio is too high, the production amount of the P-C material per unit operation will decrease. Therefore, the preferred ball-powder ratio is 0.5 to 500, more preferably 1 to 200, and further preferably 10 to 200.

[0150] In addition, after the ball mill mixing is completed, the balls are separated from the P-C material using a filter or the like.

[0151] The above-mentioned P-C material obtained by ball mill mixing can be confirmed by measuring the XRD distribution of the mixed material, such that the peaks derived from the raw materials disappear as shown in Figure 5 . The duration of the ball mill mixing can be determined by conducting a preliminary experiment on the correspondence between the mixing time and the disappearance of the peaks derived from the raw materials. In other words, the ball mill mixing is carried out until the peaks derived from the raw materials disappear in the XRD distribution of the mixed material.

[0152] Alternatively, it can also be confirmed by measuring the XPS spectrum of the mixed material, such that P-C bonds are generated as shown in Figure 3 . In this case, the duration of the ball mill mixing can be determined by conducting a preliminary experiment on the correspondence between the mixing time and the generation of P-C bonds. In other words, the ball mill mixing can be carried out until the generation of P-C bonds can be confirmed in the XPS spectrum of the mixed material.

[0153] In the ball mill mixing, by incorporating carbon materials and phosphorus in the collisions between the media and the collisions between the media and the ball mill container, a strong impact (pressure) is locally applied to the carbon materials and phosphorus. Although the detailed situation is not clear, it is believed that by applying such an impact, chemical changes that cannot be obtained in ordinary mixtures occur, and a P-C material with P-C bonds not present in the raw materials and a crystal state not seen in the raw materials can be obtained.

[0154] Therefore, if the manufacturing method of the present embodiment is used, the above-mentioned P-C material can be easily manufactured by subjecting the carbon material and phosphorus to a mixing and crushing process accompanied by compression.

[0155] In addition, by using the manufacturing method of the present embodiment, the above-mentioned P-C material can be easily manufactured by a simple method such as mixing a carbon material and phosphorus in a ball mill.

[0156] <Polymer having the ability to preferentially conduct metal ions>

[0157] The battery of the present embodiment contains a polymer having the ability to preferentially conduct metal ions as described below. In the following description, the "polymer having the ability to preferentially conduct metal ions" may sometimes be abbreviated as "polymer".

[0158] Specifically, in the battery, either one or both of the negative electrode active material layer and the solid electrolyte layer have the above-mentioned polymer. Preferably, both the negative electrode active material layer and the solid electrolyte layer of the battery have the above-mentioned polymer.

[0159] The above-mentioned polymer is a conductor of metal ions and can be used as a solid electrolyte. Since the solid electrolyte has a higher hardness than conventionally known electrolytes, it can suppress the growth of lithium dendrites that may occur in the negative electrode active material. Therefore, a battery using a solid electrolyte is expected to improve the durability of the battery.

[0160] In addition, the above-mentioned polymer shows a higher transference number of metal ions than a normal binder. In addition, the above-mentioned polymer is softer than an inorganic solid electrolyte and is less likely to cause poor contact at the interface with the solid negative electrode active material.

[0161] Therefore, when the negative electrode active material layer has the above-mentioned polymer, the negative electrode active material and the polymer are in good contact inside the negative electrode active material layer, ensuring an ion conduction state. In addition, when the solid electrolyte layer has the above-mentioned polymer, the negative electrode active material and the polymer are in good contact at the interface between the negative electrode active material layer and the solid electrolyte layer, ensuring an ion conduction state. Furthermore, if both the negative electrode active material layer and the solid electrolyte layer have the above-mentioned polymer, in addition to the above effects, an effect of mutual conduction of metal ions between the polymers contained in both the negative electrode active material layer and the solid electrolyte layer can be expected.

[0162] Through these, in a battery having the above-mentioned polymer, a good ion conduction state is ensured at the interface with the negative electrode active material, and it is easier to show high durability compared to a battery using a conventionally known electrolyte.

[0163] It should be noted that when the solid electrolyte layer has the above-mentioned polymer, the laminate of the negative electrode active material layer and the solid electrolyte layer in contact with the negative electrode active material layer corresponds to the "laminate" of the present invention.

[0164] As a polymer having the ability to preferentially conduct metal ions, for example, it is a polymer in which the transference number of metal ions is 0.4 or more when measuring the transference number of metal ions in any one of the following Compositions 1 and 2 at room temperature (25 °C). The transference number of metal ions of the polymer can be 0.5 or more, 0.6 or more, or 0.7 or more.

[0165] (Composition 1) A composition containing 33% by mass of this polymer and 67% by mass of a nonionic plasticizer

[0166] (Composition 2) A composition containing 31.9% by mass of this polymer, the total amount of the remaining metal salt and nonionic plasticizer, and having a metal ion concentration of 0.3 mol / L

[0167] When the polymer has an anionic functional group, the metal ions contained in the composition can be the counter cations of the anionic functional group or the metal ions added as a metal salt.

[0168] The polymer having the ability to preferentially conduct metal ions can be a polymer having the ability to preferentially conduct alkali metal ions.

[0169] Examples of the nonionic plasticizer include at least one of organic solvents and other resins such as fluororesins.

[0170] The organic solvent can be an aprotic solvent. The aprotic solvent can be at least one selected from the group consisting of carbonate solvents, fluorine solvents, and ether solvents. Specific examples of the organic solvent can be the specific examples of the organic solvent contained in the negative electrode material described later.

[0171] As the fluororesin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group.

[0172] The concentration of metal ions can be prepared by adding a metal salt. For example, when the metal salt is an alkali metal salt, although there is no particular limitation on the alkali metal salt, setting the alkali metal as M, MF, MCl, MBr, MI, MClO 4 , MPF 6 , MBF 4 , M 2 SO 4 , M[(C h F 2h+1 )SO 3 (h is 0 to 3), M[(C h F 2h+1 )SO 2 2 N (h is 0 to 3), etc. ​

[0173] When the polymer has the following structural unit (A), M can be the same alkali metal element as the alkali metal element contained in the structural unit (A).

[0174] Examples of the polymer having the ability to preferentially conduct metal ions include polymers containing at least one of an anionic functional group having a metal ion as a counter cation (also referred to as functional group (A)) and a functional group having an anion-trapping ability (also referred to as functional group (B)). The structure of the polymer is not particularly limited, but examples thereof include a structure having a carbon chain as a main chain, and the carbon chain may be a carbon chain formed by radical addition polymerization of a monomer having an ethylenically unsaturated group.

[0175] (Functional group (A), structural unit (A))

[0176] The metal ion as the counter cation of the functional group (A) may be at least one of an alkali metal ion and an alkaline earth metal ion, and may be an alkali metal ion. Examples of the alkali metal ion include lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, etc., and may be lithium ion, sodium ion or potassium ion, may be lithium ion or sodium ion, and may be lithium ion.

[0177] Hereinafter, a structural unit containing the functional group (A) and a metal ion as the counter cation of the functional group (A) is also referred to as a structural unit (A). The structural unit (A) may have a structure obtained by radical addition polymerization of a monomer having an ethylenically unsaturated group.

[0178] The structural unit (A) may have at least one selected from the group consisting of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, a conjugated anion of a carboxylic acid group, and a conjugated anion of a phenolic hydroxyl group as the functional group (A). The conjugated anion of a sulfonylimide group, the conjugated anion of a sulfonic acid group, and the conjugated anion of a phenolic hydroxyl group may be included in, for example, a group having a conjugated anion of a sulfonylimide group, a group having a conjugated anion of a sulfonic acid group (sulfonate group), and a group having a conjugated anion of a phenolic hydroxyl group described below.

[0179] When the functional group (A) is a group having a conjugated anion of a sulfonylimide group, the structural unit (A) may be a structural unit represented by the following formula (A1).

[0180] [Chemical formula 1]

[0181]

[0182] (In formula (A1), X is a divalent organic group having 1 to 20 carbon atoms, Y is a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, M is an alkali metal element selected from Li, Na, and K, and * represents the position where structural unit (A1) is bonded to other structural units.)

[0183] ·X

[0184] X is not particularly limited and can be a hydrocarbon group, a group having a heteroatom, or can have a heterocycle. More specifically, as X, divalent groups such as a hydrocarbon group and a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by linking groups such as -O-, -S-, -C(=O)-, or -C(=O)O- can be cited. It should be noted that when there are multiple linking groups, the linking groups are not adjacent to each other.

[0185] In addition, the above divalent group can also have a substituent that replaces the hydrogen atom bonded to the carbon atom. As the substituent, a monovalent substituent can be used, and examples thereof include a halogen atom.

[0186] The above hydrocarbon group is not particularly limited and can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group can be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group can be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Substituents such as an alkyl group, a halogen atom, and an electron-withdrawing group can also be bonded to the carbon atoms of the aromatic ring constituting the aromatic hydrocarbon group.

[0187] The number of carbon atoms that X has can be 1 to 15, can be 2 to 10, or can be 3 to 8.

[0188] The hydrocarbon group of X is preferably a phenylene group, an alkylene group having 1 to 8 carbon atoms, a polyoxyalkylene group, or a group obtained by substituting a part or all of the hydrogen atoms bonded to the carbon atoms they have with halogen atoms such as fluorine atoms, and more preferably a phenylene group or a substituted phenylene group obtained by substituting with an alkyl group, a halogen atom, an electron-withdrawing group, etc. As the electron-withdrawing group, a halogen atom, a sulfonic acid group or its salt, a sulfonate, a nitro group, a nitrile group, etc. can be cited.

[0189] X can be bonded to one or both of the nitrogen atom of the maleimide group and the sulfur atom of the sulfonyl group through the carbon atoms that X has.

[0190] ·Y

[0191] In formula (A), when Y is a monovalent organic group, there is no particular limitation on this organic group, and it may be a hydrocarbon group, a group having a heteroatom, or may have a heterocycle. More specifically, examples of Y include a monovalent group such as a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. It should be noted that when there are a plurality of linking groups, the linking groups are not adjacent to each other.

[0192] In addition, the above monovalent group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. As the substituent, it may be a monovalent substituent, and examples thereof include a halogen atom.

[0193] The above hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any of a saturated hydrocarbon group and an unsaturated hydrocarbon group.

[0194] The number of carbon atoms of Y may be 1 to 15, may be 1 to 10, may be 1 to 8, may be 1 to 5, or may be 1 to 3.

[0195] The hydrocarbon group of Y is preferably a phenyl group, an alkyl group having 1 to 5 carbon atoms, or a group obtained by substituting a part or all of the hydrogen atoms bonded to the carbon atoms of these groups with a halogen atom such as a fluorine atom, more preferably a fluoroalkyl group having 1 to 5 carbon atoms, and further preferably a fluoroalkyl group having 1 to 3 carbon atoms such as a trifluoromethyl group. The fluoroalkyl group may be a perfluoroalkyl group.

[0196] When Y is a halogen atom, as the halogen atom, it is preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

[0197] ·M +

[0198] In formula (A), M + is an alkali metal ion, preferably a lithium ion (Li + ), a sodium ion (Na + ), or a potassium ion (K + ), and more preferably a lithium ion. M + may also contain two or three kinds of ions among Li + , Na + , and K + , but preferably contains substantially only a single ion.

[0199] The group having a conjugated anion with a sulfonic acid group is a group having a group obtained by replacing the hydrogen atom of the sulfonic acid group with an alkali metal (i.e., with M as the alkali metal, -SO 3 M group).

[0200] The group having a conjugated anion with a phenolic hydroxyl group is a group having a group obtained by alkali metalizing a hydroxyl group directly bonded to an aromatic ring (i.e., a phenolic hydroxyl group (-OH)) (i.e., with M as the alkali metal, -OM group).

[0201] The structural unit (A) may be a structural unit represented by the following formula (A2).

[0202] [Chemical formula 2]

[0203]

[0204] (In formula (A2), Y 2 is a group having an alkali metalized sulfonylimide group, a group having a carboxylic acid group, a group having a phenolic hydroxyl group, or a group having a conjugated anion of sulfonic acid, and * represents the bonding position of the structural unit (A2) to other structural units.)

[0205] R 15 ~R 17 are each independently a hydrogen atom or a monovalent substituent, or R 16 is a hydrogen atom or a monovalent substituent, and R 15 and R 17 together form a divalent substituent.)

[0206] R 15 ~R 17 may be one or more hydrogen atoms, or may all be hydrogen atoms.

[0207] When R 15 ~R 17 are monovalent substituents, the monovalent substituents may also be monovalent organic groups. The number of carbon atoms in the organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0208] Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and other monovalent substituents such as a group having a heterocycle.

[0209] As the above-mentioned hydrocarbon group, there is no particular limitation, and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a phenyl group, etc.

[0210] Regarding R 15 ~R 17 For 1-valent substituents, they may have an electron-withdrawing group or may be an electron-withdrawing group itself. The electron-withdrawing group may also be bonded to the above-mentioned 1-valent organic group, and the above-mentioned 1-valent organic group may also be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate, a nitro group, a nitrile group, etc. As the halogen atom, it may be any of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0211] In the case where R 15 and R 17 together form a divalent organic group, the number of carbon atoms in the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0212] Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and a divalent substituent such as a group having a heterocycle. In addition, the above-mentioned divalent organic group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom, etc.

[0213] As the above-mentioned hydrocarbon group, there is no particular limitation, and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a propylene group, a butylene group, etc.

[0214] When Y 2 is a group having a phenolic hydroxyl group, Y 2 may be a group represented by any one of the following formulas (A21) to (A26).

[0215] [Chemical formula 3]

[0216]

[0217] (In formula (A21), R AAt least one of the groups is an -OM group, and the rest are hydrogen atoms or monovalent substituents. M is an alkali metal and can be Li, Na or K.

[0218] In formula (A22), R B At least one of the groups is an -OM group, and the rest are hydrogen atoms or monovalent substituents. M is an alkali metal and can be Li, Na or K.

[0219] In formula (A23), R C At least one of the groups is an -OM group, and the rest are hydrogen atoms or monovalent substituents. M is an alkali metal and can be Li, Na or K.

[0220] In formula (A24), R D At least one of the groups is an -OM group, and the rest are hydrogen atoms or monovalent substituents. M is an alkali metal and can be Li, Na or K.

[0221] In formula (A25), R E At least one of the groups is an -OM group, and the rest are hydrogen atoms or monovalent substituents. M is an alkali metal and can be Li, Na or K.

[0222] In formula (A26), R F At least one of the groups is an -OM group, and the rest are hydrogen atoms or monovalent substituents. M is an alkali metal and can be Li, Na or K.)

[0223] The groups represented by formulas (A21) to (A26) may have 1 to 3 -OM groups, may have 1 or 2 -OM groups, or may have 1 -OM group.

[0224] In formulas (A21) to (A26), the monovalent substituent is preferably an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate, a nitro group, a nitrile group, etc. The halogen atom can be any one of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0225] In addition, in formulas (A21) to (A26), the monovalent substituent may be an organic group having 1 to 20 carbon atoms. The number of carbon atoms of the organic group may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0226] Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted by a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and a monovalent group such as a heterocyclic group. In addition, the above monovalent group may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom.

[0227] As the above-mentioned hydrocarbon group, there is no particular limitation, and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any of a saturated hydrocarbon group and an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a phenyl group, etc. It should be noted that a monovalent organic group may also be an electron-withdrawing group by itself.

[0228] In the case where Y 2 is a group having a conjugate anion of sulfonic acid, as Y 2 , the groups represented by the following formula (A3) can be cited.

[0229] [Chemical formula 4]

[0230]

[0231] (In formula (A3), R 19 is a covalent bond or a divalent organic group.

[0232] M is Li, Na or K.)

[0233] In formula (A3), the number of carbon atoms of the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0234] Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and a divalent substituent such as a group having a heterocycle.

[0235] In addition, the above-mentioned divalent organic group may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom.

[0236] As the above-mentioned hydrocarbon group, there is no particular limitation, and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any of a saturated hydrocarbon group and an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methylene group, a phenylene group, etc.

[0237] Examples of the group having a conjugate anion of sulfonic acid include -SO 3 M, -CH 2 -SO 3 M, -C 6 H 4 -SO 3 M, etc.

[0238] (Functional group (B), structural unit (B))

[0239] The functional group (B) is a functional group having a function as an anion receptor. An anion receptor refers to a chemical species that captures an anion by forming an electrostatic interaction, a hydrogen bond, an acid-base complex, etc. with the anion.

[0240] The functional group (B) captures the counter anion of the metal ion in the metal salt and promotes the dissociation of the counter anion from the metal ion. As a result, the mobility of the metal ion increases. On the other hand, since the counter anion is captured by the polymer via the structural unit (B), the mobility of the counter anion decreases. It is considered that as a result, the transference number of the metal ion is increased in the polymer having the functional group (B). In addition, since the mobility of the metal ion increases, the polymer having the functional group (B) tends to have an increased metal ion conductivity.

[0241] There are known low-molecular chemical species (compounds, etc.) that function as anion receptors. As such compounds, for example, the compounds described in U.S. Patent No. 6,022,643, U.S. Patent No. 5,705,689, U.S. Patent No. 6,120,941, etc. can be cited. The functional group (B) has a structure corresponding to the chemical species that functions as an anion receptor. Since this functional group is fixed in the polymer, it is considered that, unlike conventional low-molecular anion receptors, it can fix the captured anion to the polymer structure and can more effectively suppress the participation in the current caused by the movement of the anion.

[0242] It should be noted that the counter anion of the alkali metal salt does not have to be a free anion that is completely ionized when captured by the above functional group, and can be captured by interacting with the above functional group in a state of forming an ionic bond or an ion pair with the metal ion.

[0243] The functional group having a function as an anion receptor may be a functional group having Lewis acidity. In this case, the above functional group can capture an anion by accepting the non-bonding electron pair of the anion and forming an acid-base complex.

[0244] As such a functional group, a functional group having an electron-deficient atom can be cited. It should be noted that an electron-deficient atom is an atom that is covalently bonded to other atoms but the outermost shell electrons of the atom do not form an octet. As the electron-deficient atom, an atom belonging to Group 13 of the periodic table can be cited. More specifically, it can be at least one of aluminum and boron, and can be boron.

[0245] In addition, as a functional group having a function as an anion receptor, a group having an azaether moiety may also be used. A group having an azaether moiety is a group having an azaether compound as a substituent, and the azaether compound is a compound obtained by substituting -O- of an ether compound with -NR E -(wherein, R E is a hydrogen atom or an organic group). The azaether moiety may be either a chain azaether moiety or a cyclic azaether moiety, and may have both a chain azaether moiety and a cyclic azaether moiety. A group having an azaether moiety may also have an electron-withdrawing group on a hydrocarbon moiety or the like, for example.

[0246] Hereinafter, a structural unit containing the functional group (B) will also be referred to as a structural unit (B). The functional group (B) may be contained in a structural unit represented by the following formula (B), for example.

[0247] [Chemical formula 5]

[0248]

[0249] (In the formula (B), W is a functional group having a function as an anion receptor, and R 1 to R 3 are each independently a hydrogen atom or a monovalent substituent, or R 3 is a hydrogen atom or a monovalent substituent, and R 1 and R 2 together form a divalent organic group. * indicates the position where the structural unit (B) is bonded to another structural unit.)

[0250] A polymer having the ability to preferentially conduct metal ions may contain one or two or more structural units represented by the formula (B).

[0251] One or more of R 1 to R 3 may be a hydrogen atom, or all may be hydrogen atoms. W may be a group represented by the following formula (B1).

[0252] When R 1 to R 3 are monovalent substituents, the monovalent substituents may also be monovalent organic groups. The number of carbon atoms of the organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0253] Examples of the monovalent substituent include a hydrocarbon group, a group having a heterocycle such as a group having a chemical structure formed by substituting one or more carbon atoms (methylene groups) in the hydrocarbon group with a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and the like. In addition, the above monovalent substituent may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom and the like.

[0254] The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a phenyl group, and the like.

[0255] It should be noted that in this specification, the aromatic hydrocarbon group is a group containing an aromatic part and may also have an aliphatic part. In addition, the cyclic hydrocarbon group in this specification is a group containing a cyclic hydrocarbon part and may also contain a linear or branched hydrocarbon part.

[0256] The monovalent substituent may have an electron-withdrawing group or may be an electron-withdrawing group itself. The electron-withdrawing group may also be bonded to the above monovalent organic group, and the above monovalent organic group may also be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonic acid ester, a nitro group, a nitrile group, and the like. Examples of the halogen atom include any of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0257] In the case where R 1 and R 2 together form a divalent organic group, the number of carbon atoms in the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0258] Examples of the divalent substituent include a hydrocarbon group, a group having a heterocycle such as a group having a chemical structure formed by substituting one or more carbon atoms (methylene groups) in the hydrocarbon group with a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and the like. In addition, the above divalent organic group may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom and the like.

[0259] The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a propylene group, a butylene group, and the like.

[0260] W preferably has a group represented by the following formula (B1).

[0261] [Chemical formula 6]

[0262]

[0263] (In formula (B1), W B is an atom belonging to Group 13 of the periodic table, and R 5 is a covalent bond or a divalent organic group, and R 6 and R 7 are a halogen atom or a monovalent organic group, or together form a divalent organic group. R 6 and R 7 may be the same group or different groups.)

[0264] W B may be at least one of aluminum and boron, and may be boron.

[0265] When R 5 is a divalent organic group, the number of carbon atoms in the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3.

[0266] Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and a monovalent substituent such as a group having a heterocycle. In addition, the above divalent organic group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom.

[0267] The substituent may be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate ester, a nitro group, and a nitrile group. As the halogen atom, any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom may be used.

[0268] R 5 may be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a group in which a hydrocarbon group or a halogen-substituted hydrocarbon group is bonded to W B via an ether bond. The halogen-substituted hydrocarbon group may be a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and may be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group. R 5 may also be a covalent bond.

[0269] When R 6 or R 7 is a halogen atom, it may be any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom.

[0270] In the case where R 6 or R 7 is a monovalent organic group, the number of carbon atoms in the monovalent organic group can be 1 to 20, can be 1 to 15, can be 1 to 10, can be 1 to 5, or can be 1 to 3.

[0271] Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and a monovalent substituent such as a group having a heterocycle.

[0272] In addition, the above monovalent organic group may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom.

[0273] The substituent can be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate ester, a nitro group, a nitrile group, etc. As the halogen atom, it can be any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0274] R 6 or R 7 can be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a group in which a hydrocarbon group or a halogen-substituted hydrocarbon group is bonded to W via an ether bond. B bonded group.

[0275] The halogen-substituted hydrocarbon group can be a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and can be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group.

[0276] W can be a group represented by the following formula (B1a) or a group represented by the following formula (B1b).

[0277] [Chemical formula 7]

[0278]

[0279] (In formula (B1a), X 1 and X 2 are each an oxygen atom (ether bond) or a covalent bond, R 11 and R 12 are each a halogen atom, a monovalent hydrocarbon group, a hydrogen atom, or a monovalent halogen-substituted hydrocarbon group, and can be a halogen atom, a monovalent hydrocarbon group, or a monovalent halogen-substituted hydrocarbon group. At least one of R 11 and R 12 can be a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group. R 11 and R 12 can be the same group or different groups.)

[0280] [Chemical Formula 8]

[0281]

[0282] (In formula (B1b), X 3 and X 4 are each an oxygen atom (ether bond) or a covalent bond, and R 13 is a divalent hydrocarbon group or a divalent halogen-substituted hydrocarbon group.)

[0283] In formula (B1a), when R 11 is a halogen atom, X 1 can be a covalent bond; when R 12 is a halogen atom, X 2 can be a covalent bond.

[0284] When R 11 or R 12 is a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group, the number of carbon atoms in the monovalent hydrocarbon group or the monovalent halogen-substituted hydrocarbon group can be 1 to 20, can be 1 to 15, can be 1 to 10, can be 1 to 5, or can be 1 to 3.

[0285] The halogen-substituted hydrocarbon group can be a group obtained by substituting part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and can be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group.

[0286] R 11 and R 12 are each independently -F, -CH 3 , -C 2 H 5 , -C 3 H 7 , -C 6 H 5 (phenyl), -C 6 H n F 5-n (n is an integer from 0 to 4, and can be an integer from 0 to 3), -CF 3 , -CH 2 CF 3 , -CH 2 CF 3 F 7 , -CH(CF 3 ) 2 , -C(CF 3 ) 2 -C 6 H 5 , -C(CF 3 ) 3 , -C 6 Hn (CF 3 ) 5-n (n is an integer from 0 to 4 and can be 1 or 2.).

[0287] In formula (B1b), the divalent hydrocarbon group or divalent halogen-substituted hydrocarbon group may have 1 to 20 carbon atoms, may have 1 to 15 carbon atoms, may have 2 to 10 carbon atoms, or may have 3 to 8 carbon atoms.

[0288] The halogen-substituted hydrocarbon group may be a group obtained by substituting part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and may be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group.

[0289] R 13 Examples include -C 2 H 4 -, -C 3 H 6 -, -C 4 H 8 -, -C 5 H 10 -, -C 6 H 12 -, -C 7 H 14 -, -C 8 H 16 -, -C 9 H 18 -, -C 10 H 20 -, etc., and groups obtained by partially or completely substituting their hydrogen atoms with fluorine, etc. More specifically, -C(CH 3 ) 2 -C(CH 3 ) 2 - are preferred.

[0290] The molar ratio m of the structural unit (B) contained in the polymer to all the structural units may be 0.2 to 0.8, may be 0.25 to 0.75, may be 0.3 to 0.7, may be 0.35 to 0.65, or may be 0.4 to 0.6.

[0291] The molar ratio n of the structural unit (A) contained in the polymer to all the structural units may be 0.25 to 0.75, may be 0.3 to 0.7, may be 0.35 to 0.65, or may be 0.4 to 0.6.

[0292] As long as the sum of m and n is 1 or less, there is no problem, and it may also be 0.95 or less. In addition, the sum of m and n may be 0.5 or more, may be 0.6 or more, may be 0.7 or more, may be 0.8 or more, may be 0.9 or more, or may be 0.95 or more.

[0293] The content of structural unit (A) relative to the total mass of the polymer may be 5 to 90% by mass, may be 20 to 80% by mass, may be 40 to 75% by mass, may be 55 to 70% by mass.

[0294] The content of structural unit (B) relative to the total mass of the polymer may be 10 to 95% by mass, may be 20 to 80% by mass, may be 25 to 60% by mass, may be 30 to 45% by mass.

[0295] The total content of structural unit (A) and structural unit (B) relative to the total mass of the polymer may be 50% by mass or more, may be 70% by mass or more, may be 90% by mass or more, may be 95% by mass or more.

[0296] The polymer may contain a structural unit different from either structural unit (A) or structural unit (B), namely structural unit (C). As structural unit (C), the structural unit represented by the following structural unit (C1), the structural unit represented by structural unit (C2), etc. may be cited.

[0297] [Chemical formula 9]

[0298]

[0299] (In formula (C1), R 21 ~R 24 are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. * represents the position where structural unit (C1) is bonded to other structural units.)

[0300] [Chemical formula 10]

[0301]

[0302] (In formula (C2), R 25 is a divalent organic group having 1 to 20 carbon atoms, R 26 and R 27 are each a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms.)

[0303] In addition, in the structural unit (C), a structural unit that is a precursor of the structural unit (A) (also referred to as the structural unit (Ap)) may also be included. As such a structural unit, unreacted structural units and intermediate structural units that cannot be converted into the structural unit (A) among the structural units that are precursors of the structural unit (A) (for example, structural units derived from the monomer (A2') described later) can be cited. For example, a group that is a conjugate acid of the structural unit (A) (that is, a group obtained by replacing the alkali metal ion that is the counter cation of the structural unit (A) with H + and a group obtained by replacing the counter cation of the structural unit (A) with a cation other than an alkali metal ion, etc.

[0304] As the counter cation contained in the structural unit (Ap), NH 4 + , organic ammonium cations, metal ions such as alkaline earth metal ions, etc.

[0305] The polymer may also contain 85 mol% or more, 90 mol% or more, or 95 mol% or more of the structural unit (A) relative to the total amount of the structural unit (A) and the structural unit (Ap).

[0306] The polymer may also contain structural units derived from hydrocarbon compounds having a plurality of ethylenically unsaturated groups such as butadiene and isoprene.

[0307] The polymer may also have a structural unit derived from a crosslinking agent. As the crosslinking agent, compounds having a plurality of ethylenically unsaturated groups in the molecule such as hexanediol diacrylate, pentaerythritol tetraacrylate, divinylbenzene, and triethylene glycol divinyl ether can be cited.

[0308] The number average molecular weight (Mn) of the polymer can be 5000 to 200000, can be 8000 to 120000, and can be 10000 to 100000.

[0309] The weight average molecular weight (Mw) of the polymer can be 5000 to 300000, can be 10000 to 250000, and can be 20000 to 100000.

[0310] The molecular weight distribution (Mw / Mn) of the polymer can be 1.0 to 3.5, and can be 1.3 to 2.7.

[0311] The number average molecular weight and the weight average molecular weight of the polymer can be measured by, for example, gel permeation chromatography.

[0312] The method for producing the polymer is not particularly limited, and examples thereof include a method of polymerizing a monomer mixture containing at least one of a monomer having an anionic functional group ionized by an alkali metal or a monomer having a precursor of the anionic functional group (hereinafter referred to as monomer (A')) and a monomer (B') having a functional group functioning as an anion receptor. The monomer may further contain a monomer (C') different from monomer (A') and monomer (B').

[0313] Monomer (A') and monomer (B') may have an ethylenically unsaturated group. In this case, monomer (A') and monomer (B') can be polymerized by radical addition polymerization. In this case, the monomer can be polymerized in the presence of an initiator. That is, the polymerization reaction can be carried out in a polymerizable composition containing the monomer and the initiator.

[0314] Monomer (A') is a monomer that derives a structural unit (A) in the polymer. Examples of monomer (A') include monomer (A1') represented by the following formula (A1'), monomer (A2') represented by formula (A2'), etc.

[0315] [Chemical formula 11]

[0316]

[0317] (In formula (A1'), X, Y, and M + have the same meanings as in formula (A).)

[0318] [Chemical formula 12]

[0319]

[0320] (In formula (A2'), R 15 ~R 17 have the same meanings as R 15 ~R 17 in formula (A2), and Y2' is a group capable of deriving a phenolic hydroxyl group corresponding to the -OM group possessed by Y 2 in formula (A2), or a group having a group capable of deriving a sulfonic acid group corresponding to the -SO 2 M group possessed by Y 3 .)

[0321] Y 2 ' may also be the same group as Y 2 , but may be a group that is a precursor of Y 2 . That is, Y 2 ' is a group that, when compared with the desired Y 2 has the -OM group or -SO 3At the same position of the M group, there is a group that can be converted into an -OM group or -SO 3 a group of the M group.

[0322] As a group that can be derived to the phenolic hydroxyl group corresponding to the -OM group possessed by Y 2 , for example, hydrolyzable groups can be cited. By hydrolyzing this hydrolyzable group, a phenolic hydroxyl group can be introduced at the position corresponding to the -OM group possessed by Y 2 .

[0323] As the hydrolyzable group, for example, an alkoxide group or -OSi(R k ) 3 group (R k is a monovalent organic group such as a hydrocarbon group). The phenolic hydroxyl group can be converted into an -OM group, for example, by reacting with an alkaline salt of an alkali metal such as MOH, M 2 CO 3 , MHCO 3 .

[0324] Similarly, as a group that can be derived to the sulfonic acid group corresponding to the -SO 2 M group possessed by Y 3 , for example, a group that can be derived to a sulfonic acid ester group, -SO 2 Cl group, etc. sulfonic acid groups (-SO 3 H) can be cited. The sulfonic acid group can be converted into an -OM group, for example, by reacting with a salt of an alkali metal such as MOH, M 2 CO 3 , MHCO 3 , an alkali metal halide, etc.

[0325] In addition, for the -SO 2 Cl group, it can also react with MOH to be converted into -SO 3 M group. When an excessive amount of MOH is used, most of the -SO 2 Cl group can also be converted into -SO 3 M group. In the said reaction, a part of the -SO 2 Cl group may become -SO 3 H group, but regarding -SO 3 H group, it can also react with an alkali containing M separately to form -SO 3 M group.

[0326] In addition, Y 2 ’ can also be a group that has the same anionic part as Y 2 and forms a salt with a cation other than an alkali metal ion. In this case, by performing a cation exchange reaction on the obtained polymer, the structural unit (A2) can be derived.

[0327] The reaction rate of Y2’ (Y 2 in the total amount of ’ converted to Y 2 of Y 2 ’s proportion) can be 85 mol% or more, 90 mol% or more, or 95 mol% or more.

[0328] Monomer (B') is a monomer that derives a structural unit (B) in the polymer. As the monomer (B’), the monomer (B’) represented by the following formula (B’) can be cited.

[0329] [Chemical formula 13]

[0330]

[0331] (In the formula, R 1 ~R 3 and W have the same meanings as R 1 ~R 3 and W in formula (B).)

[0332] The radical polymerization initiator can be either a thermal initiator or a photoinitiator. For example, as the thermal initiator, 2,2-azobis(isobutyronitrile) (AIBN) can be cited; 2,2-azobis(2-methylbutyronitrile) (AMBN), 2,2-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1-azobis(1-cyclohexanecarbonitrile) (ACHN, V-40), dimethyl-2,2-azobisisobutyrate (MAIB) and other azo-based initiators; benzoyl peroxide, bis(2-ethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, bis(2,4-dichlorobenzoyl) peroxide and other organic peroxides, etc.

[0333] As the photoinitiator, oxime-based compounds, metallocene-based compounds, acylphosphine-based compounds, aminophenone compounds, etc. can be cited.

[0334] One or more than two kinds of initiators can be used.

[0335] <Solid electrolyte>

[0336] In addition to the above-mentioned polymer, the solid electrolyte layer can also contain other known solid electrolytes (ion-conductive inorganic solid electrolytes).

[0337] As the ion-conductive inorganic solid electrolyte, there is no particular limitation, and it can be an oxide (oxide-based solid electrolyte), a sulfide (sulfide-based solid electrolyte), a hydride (hydride-based solid electrolyte), a halide (halide-based solid electrolyte), etc. The ion-conductive inorganic solid electrolyte can contain at least one of an alkali metal element and an alkaline earth metal element, and can contain an alkali metal element.

[0338] (Oxide-based solid electrolyte)

[0339] Examples of the oxide-based solid electrolyte include oxides such as perovskite-type oxides, NASICON-type oxides, LISICON-type oxides, garnet-type oxides, and substances obtained by doping other cations or anions into the oxides, etc.

[0340] Examples of the perovskite-type oxides include Li a La 1-a TiO 3 (0 < a < 1) and other Li-La-Ti-based oxides, Li b La 1-b TaO 3 (0 < b < 1) and other Li-La-Ta-based oxides, Li c La 1-c NbO 3 (0 < c < 1) and other Li-La-Nb-based oxides, etc.

[0341] Examples of the NASICON-type oxides include Li 1+d Al d Ti 2-d (PO 4 ) 3 (0 ≤ d ≤ 1), etc. The NASICON-type oxide is an oxide represented by Li m M 1 n M 2 o P p O q (wherein, M 1 is one or more elements selected from the group consisting of B, Al, Ga, In, C, Si, Ge, Sn, Sb, and Se. M 2 is one or more elements selected from the group consisting of Ti, Zr, Ge, In, Ga, Sn, and Al. m, n, o, p, and q are arbitrary positive numbers.) Examples of the oxide include Li 1+x+y Al x (Ti, Ge) 2-x Si y P 3-y O 12 (0 < x < 2, 0 < y < 3) (LATP), etc.

[0342] Examples of the LISICON-type oxides include Li 4 M 3 O 4 -Li 3 M 4O 4 (M 3 is one or more elements selected from the group consisting of Si, Ge, and Ti. M 4 is one or more elements selected from the group consisting of P, As, and V.) The oxides and the like represented by

[0343] As the garnet-type oxide, Li 7 La 3 Zr 2 O 12 (LLZ), Li 7-a2 La 3 Zr 2-a2 Ta a2 O 12 (LLZT, 0 < a2 < 1 can be, 0.1 < a2 < 0.8 can be, 0.2 < a2 < 0.6) and other Li-La-Zr-based oxides and the like.

[0344] The oxide-based solid electrolyte can be a crystalline material or an amorphous material.

[0345] As the oxide-based solid electrolyte, Li 6.6 La 3 Zr 1.6 Ta 0.4 O 12 , Li 0.33 La 0.55 TiO 3 and the like.

[0346] (Sulfide-based solid electrolyte)

[0347] As the sulfide-based solid electrolyte, Li 2 S-P 2 S 5 -based compounds, Li 2 S-SiS 2 -based compounds, Li 2 S-GeS 2 -based compounds, Li 2 S-B 2 S 3 -based compounds, Li 2 S-P 2 S 3 -based compounds, LiI-Si 2 S-P 2 S 5 , LiI-Li 2 S-P 2 O 5 , LiI-Li 3 PO 4 -P2 S 5 、 Li 10 GeP 2 S 12 etc.

[0348] It should be noted that in this specification, the expression "system compound" referring to a sulfide-based solid electrolyte is used as a general term for solid electrolytes mainly containing the "Li 2 S", "P 2 S 5 ", etc. as raw materials. For example, for Li 2 S-P 2 S 5 system compounds, it includes solid electrolytes containing Li 2 S and P 2 S 5 and further containing other raw materials. In addition, for Li 2 S-P 2 S 5 system compounds, it also includes solid electrolytes with different mixing ratios of Li 2 S and P 2 S 5 .

[0349] As Li 2 S-P 2 S 5 system compounds, examples include Li 2 S-P 2 S 5 , Li 2 S-P 2 S 5 -LiI, Li 2 S-P 2 S 5 -LiCl, Li 2 S-P 2 S 5 -LiBr, Li 2 S-P 2 S 5 -Li 2 O, Li 2 S-P 2 S 5 -Li 2 O-LiI, Li 2 S-P 2 S 5 -Z m S n (m, n are positive numbers. Z is Ge, Zn or Ga), etc.

[0350] As Li 2S-SiS 2 Compounds of this system include Li 2 S-SiS 2 、Li 2 S-SiS 2 -LiI, Li 2 S-SiS 2 -LiBr, Li 2 S-SiS 2 -LiCl, Li 2 S-SiS 2 -B 2 S 3 -LiI, Li 2 S-SiS 2 -P 2 S 5 -LiI, Li 2 S-SiS 2 -Li 3 PO 4 、Li 2 S-SiS 2 -Li 2 SO 4 、Li 2 S-SiS 2 -Li x MO y (x and y are positive numbers. M is P, Si, Ge, B, Al, Ga or In, etc.)

[0351] As Li 2 S-GeS 2 Compounds of this system include Li 2 S-GeS 2 、Li 2 S-GeS 2 -P 2 S 5 etc.

[0352] The sulfide solid electrolyte can be a crystalline material or an amorphous material.

[0353] (Hydride solid electrolyte)

[0354] As the hydride solid electrolyte material, examples include LiBH 4 、LiBH 4 -3KI, LiBH 4 -PI 2 、LiBH 4 -P 2 S 5 、LiBH 4 -LiNH 2, 3LiBH 4 -LiI, LiNH 2 , Li 2 AlH 6 , Li(NH 2 ) 2 , Li 2 NH, LiGd(BH 4 ) 3 , Li 2 (BH 4 )(NH 2 ), Li 3 (NH 2 ), Li 4 (BH 4 )(NH 2 ) 3 etc.

[0355] (Halide solid electrolyte)

[0356] As the halide solid electrolyte, compounds containing Li, metal elements, and halogen elements can be cited, etc.

[0357] The halide solid electrolyte can be a crystalline material or an amorphous material.

[0358] As the ion-conductive inorganic solid electrolyte, compounds obtained by replacing part or all of Li in the compounds cited as specific examples of the oxide solid electrolyte, sulfide solid electrolyte, hydride solid electrolyte, or halide solid electrolyte with Na, K, Rb, or Cs can also be cited.

[0359] The content of the ion-conductive inorganic solid electrolyte relative to the total amount of the electrolyte composition can be 50% by mass or more, can be 55% by mass or more, can be 60% by mass or more, can be 65% by mass or more, can be 70% by mass or more. In addition, the content of the ion-conductive inorganic solid electrolyte relative to the total amount of the electrolyte composition can be 95% by mass or less, can be 90% by mass or less, can be 85% by mass or less. In addition, the content of the ion-conductive inorganic solid electrolyte relative to the total amount of the electrolyte composition can be 50 to 95% by mass, can be 55 to 90% by mass, can be 60 to 85% by mass.

[0360] The content of the ion-conductive inorganic solid electrolyte may be 15% by volume or more, 25% by volume or more, 35% by volume or more, 40% by volume or more, 45% by volume or more, or 50% by volume or more with respect to the total amount of the electrolyte composition. In addition, the content of the ion-conductive inorganic solid electrolyte may be 90% by volume or less, 80% by volume or less, 70% by volume or less, or 60% by volume or less with respect to the total amount of the electrolyte composition. Further, the content of the ion-conductive inorganic solid electrolyte may be 15 to 90% by volume, 25 to 80% by volume, or 35 to 60% by volume with respect to the total amount of the electrolyte composition. It should be noted that in this specification, unless otherwise specified, the volume % is calculated based on the volume of each component before mixing contained in the electrolyte composition, and in the case where the mass ratio of each component contained in the electrolyte composition is known, it may be a value obtained by dividing the mass ratio of each component by the density.

[0361] The ion-conductive inorganic solid electrolyte may be an ion-conductive inorganic solid electrolyte whose particle surface has been treated. Specifically, examples include treatment for removing the surface non-conductive layer with an acid, treatment for forming a covalent bond with an atom, etc. The acid is not particularly limited, but examples include hydrochloric acid, nitric acid, phosphoric acid, etc.

[0362] <Other materials>

[0363] In addition to the above polymer, the solid electrolyte layer may further contain a metal salt. The metal salt may be at least one of an alkali metal salt and an alkaline earth metal salt, and may be an alkali metal salt. The alkali metal salt is not particularly limited, but when the alkali metal is set as M, examples include MF, MCl, MBr, MI, MClO 4 , MPF 6 , MBF 4 , M 2 SO 4 , M[(C h F 2h+1 )SO 3 (h is 0 to 3), M[(C h F 2h+1 )SO 2 2 N (h is 0 to 3), etc. In the case where the polymer has a structural unit (A), M may be the same alkali metal element as the alkali metal element contained in the structural unit (A). M may be lithium, sodium, or potassium, and may be lithium.

[0364] ​The solid electrolyte layer can also be made into a composite further containing other resins such as fluororesins, fabrics such as non-woven fabrics, porous materials, viscosity modifiers, etc. As the fluororesin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group. Examples of the fluororesin include poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyvinylidene fluoride (PVDF), etc.

[0365] 《Negative Electrode Material》

[0366] When the negative electrode active material layer has the above polymer, the negative electrode material constituting the negative electrode active material layer corresponds to the "negative electrode material" of the present invention. The negative electrode material contains a negative electrode active material and a polymer having the ability to preferentially conduct metal ions.

[0367] [Organic Solvent]

[0368] In addition, the negative electrode material may also contain an organic solvent. As the organic solvent, an aprotic solvent can be used. For example, it can be at least one selected from the group consisting of carbonate solvents, fluorine solvents, and ether solvents.

[0369] Examples of the carbonate solvents include chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate, etc.

[0370] Examples of the ether solvents include cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, and 1,3-dioxolane; chain ethers such as 1,2-diethoxyethane and ethoxymethoxyethane, etc.

[0371] Examples of the fluorine solvents include hydrofluorocarbons such as perfluorooctane; hydrofluoroethers such as methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether, and hydrofluoroolefins such as 1,3,3,3-tetrafluoropropene, etc.

[0372] In addition, examples of the solvent include aprotic solvents such as dimethyl sulfoxide (DMSO); amide solvents such as dimethylformamide (DMF) and dimethylacetamide (DMA).

[0373] The organic solvent can be used alone or as a mixed solvent containing two or more organic solvents. When using a mixed solvent, for example, the organic solvent can be a mixed solvent containing two or more carbonate solvents, a mixed solvent containing two or more cyclic carbonates, or a mixed solvent containing ethylene carbonate and propylene carbonate.

[0374] The content of the organic solvent may be 1 to 45% by mass, may be 4 to 40% by mass, and may be 7 to 30% by mass relative to the total amount of the inorganic material.

[0375] The content of the organic solvent may be 1 to 70% by volume, may be 4 to 60% by volume, and may be 20 to 50% by volume relative to the total amount of the inorganic material. The mass ratio of the polymer in the inorganic material to the organic solvent may be 1:0.5 to 1:3, and may be 1:1 to 1:2.5.

[0376] If a battery having the above-described configuration is used, a battery that ensures a good ion conduction state with the negative electrode active material and has high durability can be obtained. In addition, if the negative electrode material and the laminate having the above-described configuration are used, a negative electrode material and a laminate that can easily ensure a good ion conduction state with the negative electrode active material can be obtained.

[0377] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above examples. The shapes, combinations, etc. of the respective constituent members shown in the above examples are one example, and various changes can be made based on design requirements and the like without departing from the gist of the present invention.

[0378] For example, in the above-described embodiment, a lithium ion secondary battery has been described, but as the metal ion intercalated or deintercalated into the negative electrode active material, an alkali metal can be used. As the applicable alkali metal, lithium or sodium is preferred, and lithium is more preferred.

[0379] When sodium is used as the alkali metal, as the negative electrode active material, a material in which sodium ions are intercalated or deintercalated when a counter electrode made of metallic sodium is used and a voltage of 0.1 V or more is applied is used.

[0380] It is considered that even if the metal species is changed to another alkali metal such as sodium from lithium, since the above-described polymer has the ability to preferentially conduct alkali metal ions, the movement of alkali metal ions is not easily hindered, and the reaction with the negative electrode occurs smoothly. Thus, a battery that ensures a good ion conduction state with the negative electrode active material and has high durability, a negative electrode material, and a laminate that can easily ensure a good ion conduction state with the negative electrode active material can be provided.

[0381] The present invention includes the following aspects.

[0382] <1> A battery having:

[0383] a positive electrode,

[0384] a negative electrode having a negative electrode active material layer,

[0385] a solid electrolyte layer disposed between the positive electrode and the negative electrode and in contact with the negative electrode active material layer, and

[0386] An outer package body containing the above-mentioned positive electrode, the above-mentioned negative electrode, and the above-mentioned solid electrolyte layer

[0387] The above-mentioned negative electrode active material layer contains a negative electrode active material that uses an alkali metal as a counter electrode and embeds or de-embeds ions of the above-mentioned alkali metal when a voltage of 0.1 V or more is applied.

[0388] Either or both of the above-mentioned negative electrode active material layer and the above-mentioned solid electrolyte layer contain a polymer having the ability to preferentially conduct metal ions.

[0389] The above-mentioned negative electrode active material is a phosphorus-carbon composite material containing phosphorus atoms and carbon atoms.

[0390] The content rate of phosphorus atoms in the above-mentioned phosphorus-carbon composite material is 10% by mass or more and 95% by mass or less.

[0391] The content rate of carbon atoms in the above-mentioned phosphorus-carbon composite material is 5% by mass or more and 90% by mass or less.

[0392] The weight reduction rate WL at a measurement temperature of 620 °C obtained by thermogravimetric measurement under the above-mentioned conditions 620 and the weight reduction rate WL at a measurement temperature of 780 °C 780 The ratio WL 620 / WL 780 is 0.1 or more and 0.9 or less.

[0393] The above-mentioned polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capture ability.

[0394] <2>The battery according to <1>, wherein both the above-mentioned negative electrode active material layer and the above-mentioned solid electrolyte layer contain the above-mentioned polymer.

[0395] <3>The battery according to <1> or <2>, wherein the above-mentioned anionic functional group has at least one of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, and a conjugated anion of a phenolic hydroxyl group.

[0396] <4>The battery according to <3>, wherein the above-mentioned polymer has the above-mentioned anionic functional group and a functional group having an anion capture ability.

[0397] The above-mentioned functional group having an anion capture ability has Lewis acidity.

[0398] <11>A negative electrode material, containing:

[0399] A negative electrode active material, and

[0400] A polymer having the ability to preferentially conduct metal ions

[0401] When an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied, the negative electrode active material embeds or de-embeds ions of the alkali metal.

[0402] The negative electrode active material is a phosphorus-carbon composite material containing phosphorus atoms and carbon atoms.

[0403] The content rate of phosphorus atoms in the phosphorus-carbon composite material is 10 mass% or more and 95 mass% or less.

[0404] The content rate of carbon atoms in the phosphorus-carbon composite material is 5 mass% or more and 90 mass% or less.

[0405] The weight reduction rate WL at a measurement temperature of 620 °C obtained by thermogravimetric measurement under the above conditions 620 and the weight reduction rate WL at a measurement temperature of 780 °C 780 The ratio WL 620 / WL 780 is 0.1 or more and 0.9 or less.

[0406] The polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capturing ability.

[0407] <12> The negative electrode material according to <11>, wherein the anionic functional group has at least one of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, and a conjugated anion of a phenolic hydroxyl group.

[0408] <13> The negative electrode material according to <12>, wherein the polymer has the anionic functional group and a functional group having an anion capturing ability.

[0409] The functional group having an anion capturing ability has Lewis acidity.

[0410] <21> A laminate having:

[0411] a positive electrode,

[0412] a negative electrode having a negative electrode active material layer, and

[0413] a solid electrolyte layer disposed between the positive electrode and the negative electrode and in contact with the negative electrode active material layer,

[0414] The solid electrolyte layer contains a polymer having the ability to preferentially conduct metal ions.

[0415] The negative electrode active material contained in the negative electrode active material layer embeds or de-embeds ions of the alkali metal when an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied.

[0416] The above-mentioned negative electrode active material is a phosphorus-carbon composite material containing phosphorus atoms and carbon atoms.

[0417] The content rate of phosphorus atoms in the above-mentioned phosphorus-carbon composite material is 10% by mass or more and 95% by mass or less.

[0418] The content rate of carbon atoms in the above-mentioned phosphorus-carbon composite material is 5% by mass or more and 90% by mass or less.

[0419] The weight reduction rate WL at the measurement temperature of 620 °C obtained by thermogravimetric measurement under the above conditions 620 and the weight reduction rate WL at the measurement temperature of 780 °C 780 The ratio WL 620 / WL 780 is 0.1 or more and 0.9 or less.

[0420] The above-mentioned polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capturing ability.

[0421] <22> The battery according to <21>, wherein both the above-mentioned negative electrode active material layer and the above-mentioned solid electrolyte layer contain the above-mentioned polymer.

[0422] <23> The negative electrode material according to <21> or <22>, wherein the above-mentioned anionic functional group has at least one of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, and a conjugated anion of a phenolic hydroxyl group.

[0423] <24> The negative electrode material according to <23>, wherein the above-mentioned polymer has the above-mentioned anionic functional group and a functional group having an anion capturing ability.

[0424] The above-mentioned functional group having an anion capturing ability has Lewis acidity.

[0425] Examples

[0426] The present invention will be described below through examples, but the present invention is not limited to these examples.

[0427] <Manufacture of each material>

[0428] (Manufacture of monomer (A1) and monomer (B1))

[0429] Prepare monomer (A1) and monomer (B1) as described below.

[0430] (Synthesis of monomer A1)

[0431] Trifluoromethanesulfonamide (52.5 mmol, 7.83 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated acetonitrile (150 mL, manufactured by Kanto Chemical Co., Inc.) under a nitrogen atmosphere. Lithium hydroxide (105 mmol, 2.51 g, manufactured by Tokyo Chemical Industry Co., Ltd.) and 4-acetamidobenzenesulfonyl chloride (50 mmol, 11.68 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were successively added to this solution, and the mixture was heated under reflux for 5 hours. After cooling to room temperature, an excess of acetonitrile (700 mL) was added to precipitate a solid, which was separated by filtration and washed with dichloromethane (manufactured by Kanto Chemical Co., Inc.) to obtain Intermediate 1. The yield was 97.1%. The structural formula of Intermediate 1 is shown below.

[0432] [Chemical Formula 14]

[0433]

[0434] 5% hydrochloric acid (22.5 mL) was added to Intermediate 1 (15 mmol, 5.28 g) under a nitrogen atmosphere, and the mixture was stirred at 90 °C for 2 hours. After cooling to room temperature, based on confirmation using pH test paper etc., an aqueous lithium hydroxide solution was added until the pH reached 7 or higher, and then a solid was obtained by drying under reduced pressure. The obtained solid was extracted with an acetonitrile solution and dried under reduced pressure to obtain Intermediate 2. The yield was 92.6% based on the raw material of the above Intermediate 1. The structural formula of Intermediate 2 is shown below.

[0435] [Chemical Formula 15]

[0436]

[0437] Maleic anhydride (13.3 mmol, 1.30 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated 1,4-dioxane (manufactured by Kanto Chemical Co., Inc.) under a nitrogen atmosphere. A solution of Intermediate 2 (13.2 mmol, 4.09 g) adjusted under a nitrogen atmosphere in dehydrated tetrahydrofuran (26.4 mL, manufactured by Kanto Chemical Co., Inc.) was added dropwise to this solution in total amount, and the mixture was stirred at room temperature for 12 hours. After the reaction, the precipitate was filtered, and vacuum dried at 60 °C for 4 hours to obtain a solid containing Intermediate 3. The structural formula of Intermediate 3 is shown below.

[0438] [Chemical Formula 16]

[0439]

[0440] Under a nitrogen atmosphere, a solid containing Intermediate 3 (14.0 mmol, 5.70 g) and sodium acetate (13.3 mmol, 1.09 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to acetic anhydride (12.3 mL, manufactured by Tokyo Chemical Industry Co., Ltd.), and the mixture was stirred at 70 °C for 3 hours. The total amount of the reaction solution was dropped into an excess of diethyl ether (manufactured by Kanto Chemical Co., Inc.) at 0 °C, and the precipitate was recovered by filtration. The precipitate was extracted with dehydrated acetonitrile (manufactured by Kanto Chemical Co., Inc.) under an inert atmosphere and dried under reduced pressure to obtain monomer A1. The yield through all the steps was 72.8%. Monomer A1 is shown below. Monomer A1 contains a conjugated anion of a sulfonylimide group as an anionic functional group.

[0441] [Chemical Formula 17]

[0442]

[0443] (Synthesis of Monomer B1)

[0444] For monomer B1 (the following formula (B1)), the synthesis was carried out as follows.

[0445] To 4.21 g (5 mmol) of anhydrous magnesium sulfate (MgSO 4 ) and 4.14 g (35 mmol) of pinacol, 175 mL of diethyl ether was added. To the turbid solution obtained by stirring, 4-vinylphenylboronic acid (VPBA, 5.18 g (35 mmol)) was added, and the mixture was stirred at room temperature for 19 hours. The solution obtained by filtration was evaporated and purified by silica gel chromatography (eluent: hexane / ethyl acetate 20 / 1 (volume ratio)) to obtain the target monomer B1 in a yield of 92.1%. Monomer B1 is shown below. Monomer B1 contains a boron atom showing Lewis acidity. The group containing the boron atom functions as a functional group having an anion-capturing ability.

[0446] [Chemical Formula 18]

[0447]

[0448] (Manufacture of Polymer 1 (Polymer 1) Having the Ability to Preferentially Conduct Metal Ions)

[0449] Dissolve 0.558 g of monomer A1, 0.149 g of styrene, and 11.7 mg of azobisisobutyronitrile (AIBN) in 13.4 mL of dehydrated acetonitrile. Add tetralin as an internal standard substance, and while confirming the monomer consumption rate, react at 60 °C for 24 hours under a nitrogen atmosphere. By dialyzing the polymerization solution in acetonitrile and performing vacuum drying at 120 °C, 0.64 g of polymer 1 was obtained (yield 87%). The monomer feed ratio was A1:styrene = 52:48. The monomer feed ratio was calculated from the 1 1H-NMR of the copolymer.

[0450] Polymer 1 had a number-average molecular weight Mn = 8.7×10 4 and a weight-average molecular weight Mw = 2.2×10 5 with a molecular weight distribution Mw / Mn = 2.55.

[0451] (Production of Polymer 2 (Polymer 2) with the ability to preferentially conduct metal ions)

[0452] Mix the solutions of each component so that it becomes 0.78 g of monomer A1, 0.46 g of monomer B1, and 16.4 mg of azobisisobutyronitrile (AIBN). Add tetralin as an internal standard substance, and while confirming the monomer consumption rate, react at 60 °C for 24 hours under a nitrogen atmosphere. Use dehydrated acetonitrile as the solvent. By dialyzing the reaction solution in acetonitrile and performing vacuum drying at 120 °C, 1.08 g of polymer 2 was obtained (yield 87%). The monomer feed ratio was A1:B1 = 48:52. The monomer feed ratio was calculated from the 1 1H-NMR of the copolymer.

[0453] Polymer 2 had a number-average molecular weight Mn = 7.4×10 4 and a weight-average molecular weight Mw = 1.8×10 5 with a molecular weight distribution Mw / Mn = 2.40.

[0454] (Production of negative electrode active material)

[0455] Weigh black phosphorus manufactured by RASA Industries and CSCNT (cup-stacked carbon nanotubes: manufactured by GSI Creos Corporation) at a mass ratio of P:C = 6:4 (total amount 0.5 g), and mix them using a ball mill under the following conditions to obtain a P-C material. Take a TEM photograph of the obtained P-C material, and as Figure 4 shown, it was confirmed to be a core-shell structure in which a carbon film covered the surface of the core particles containing phosphorus atoms.

[0456] (Ball mill mixing conditions)

[0457] Apparatus: Retsch PM-100

[0458] Container: ZrO 2 Prepare a 50 mL container

[0459] Medium: ZrO 2 Prepare 5 mmφ balls, 60 g

[0460] Atmosphere: Argon is sealed

[0461] Sample amount: 0.5 g based on the mixture of raw materials

[0462] Ball / powder ratio: 120 (weight ratio)

[0463] Mixing time: 12 hours

[0464] For the obtained P-C material, lithium metal is used as the counter electrode and charged at a charging rate of 0.2C. As a result, the average charging potential of the P-C material with respect to the capacity (mAh / g) during charging is 0.1 V or more. It is confirmed that the obtained P-C material is a material that intercalates lithium ions when lithium (alkali metal) is used as the counter electrode and a voltage of 0.1 V or more is applied.

[0465] In the obtained P-C material, the phosphorus atom content is 60 mass%, and the carbon atom content is 40 mass%. Since the airtightness of the container used during the above manufacturing process is extremely high, it is judged that the content ratio of each atom in the P-C material is equal to the raw material ratio.

[0466] In addition, the weight loss rate WL at a measurement temperature of 620 °C of the obtained P-C material obtained by thermogravimetric measurement under the following conditions 620 and the weight loss rate WL at a measurement temperature of 780 °C 780 The ratio WL 620 / WL 780 is 0.58.

[0467] (Thermogravimetric measurement)

[0468] Precisely weigh 10 mg of the phosphorus-carbon composite material as a sample, and use a thermogravimetric measurement device to measure the weight change when heating from 50 °C to 780 °C at a heating rate of 10 °C / minute in a nitrogen gas stream.

[0469] (Weight loss rate)

[0470] The ratio of the weight of the sample at the measurement temperature to the weight of the precisely weighed sample is defined as the weight loss rate (weight%) at the measurement temperature.

[0471] Furthermore, the weight loss rate WL at a measurement temperature of 300 °C of the obtained P-C material obtained by the above thermogravimetric measurement 300 and the weight loss rate WL at a measurement temperature of 600 °C600 The ratio WL 300 / WL 600 is -0.02.

[0472] For the obtained P-C material, measurement was carried out according to the above (XPS energy spectrum measurement conditions), and as a result, a peak indicating the bond between phosphorus atoms and carbon atoms was confirmed.

[0473] For the obtained P-C material, measurement was carried out according to the above (XRD distribution measurement conditions). In the XRD distribution, the intensity I at 2θ = 20° 20 is 3680, the intensity I at 2θ = 26.3° 26.3 is 3350, and the intensity I at 2θ = 40° 40 is 2008. In addition, |P| / |B| is 1.17. The P-C material showing these values satisfies the following formulas (1) to (3).

[0474] |P| / |B| < 2 (1)

[0475] P = I 26.3 -I 40 (2)

[0476] B = (I 20 -I 40 ) × (26.3 - 40) / (20 - 40) (3)

[0477] <1. Confirmation of the effect of a polymer having the ability to preferentially conduct metal ions (negative electrode material)>

[0478] In this example, in order to confirm the effect in the negative electrode material of a polymer having the ability to preferentially conduct metal ions, the cycle characteristics were confirmed for the following Example 1 and Comparative Example 1 in which only the composition of the negative electrode material was changed. Although Comparative Example 1 contains the above polymer in the solid electrolyte layer, from the above viewpoints, it is treated as a comparative example only for judging the effect of Example 1.

[0479] [Example 1]

[0480] (Fabrication of evaluation battery)

[0481] (1) Fabrication of negative electrode 1

[0482] Weigh the P-C material, conductive material, and binder obtained in the above (Fabrication of negative electrode active material) to prepare a mixture of [P-C material]:[conductive material]:[binder]:[polymer 1] = 80:10:5:5 (mass ratio). The materials used are as follows. The obtained mixture corresponds to the "negative electrode material" in the present invention.

[0483] Binder: Polyvinylidene fluoride PVdF (KUREHA KF Polymer #1100, manufactured by KUREHA CORPORATION)

[0484] Conductive material: Vapor grown carbon fiber VGCF

[0485] The above mixture was kneaded with a solvent (N-methyl-2-pyrrolidone (NMP)) using an agate mortar to prepare a negative electrode slurry. Since the viscosity of the slurry changes according to the temperature of the slurry, the amount of the solvent (slurry concentration) was adjusted for the purpose of adjusting the viscosity. At this time, the allowable range of the content rate of the solid matter (total of P-C material, conductive material, and binder) in the negative electrode slurry was set to 30 to 60 mass%.

[0486] The negative electrode slurry was coated on a copper foil current collector using a doctor blade, and then, after drying by blowing air at 120 °C for 1 hour to remove the solvent, a laminate was obtained. The obtained laminate was pressed under a pressure of 10 mPa for 10 seconds and then further dried in vacuum at 120 °C for 12 hours to obtain a negative electrode.

[0487] It should be noted that the production of the above negative electrode slurry and the production of the negative electrode were carried out in a glove box under an argon atmosphere.

[0488] (2) Fabrication of Lithium-Ion Secondary Battery

[0489] The negative electrode 1, counter electrode, and electrolyte were combined (laminated) to fabricate the lithium-ion secondary battery (coin-type battery R2032) of Example 1. The assembly of the lithium-ion secondary battery was carried out in a glove box under an argon atmosphere.

[0490] The laminate of the negative electrode 1, counter electrode, and electrolyte corresponds to the "laminate" in the present invention.

[0491] The battery obtained by accommodating the laminate in the coin battery case of R2032 corresponds to the "battery" in the present invention.

[0492] As the counter electrode, a lithium metal foil was used.

[0493] As the electrolyte, an electrolyte composition containing the polymer 1, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and an organic solvent (ethylene carbonate:propylene carbonate = 1:1 (volume ratio), manufactured by KISHIDA CHEMICAL CO., LTD.) in a mass ratio of 17:17:66 was used.

[0494] [Comparative Example 1]

[0495] (1) Fabrication of Negative Electrode 2

[0496] Except for preparing a mixture of [P-C material]:[conductive material]:[binder]=80:10:10 (mass ratio), the same operations as those for the negative electrode 1 of Example 1 were carried out to fabricate the negative electrode 2.

[0497] Binder: polyvinylidene fluoride PVdF (KUREHA KF Polymer #1100, manufactured by KUREHA CORPORATION)

[0498] Conductive material: vapor grown carbon fiber VGCF

[0499] (2) Fabrication of a lithium ion secondary battery

[0500] Except for using the negative electrode 2, the same operations as those for Example 1 were carried out to fabricate the lithium ion secondary battery of Comparative Example 1.

[0501] (Measurement of charge-discharge capacity)

[0502] Using the fabricated lithium ion secondary battery, a charge-discharge test was carried out under the conditions shown below while maintaining at 25°C. Here, the theoretical capacity of phosphorus was set to 2600 mAh / g, and the counter electrode capacity was set to 2600 mA / g for a 1C current of charging or discharging in 1 hour. In the charge-discharge test, the 1C current was calculated from the mass of phosphorus contained in the negative electrode. Regarding the definition of 1C in the examples, it was set the same as follows.

[0503] Minimum charging voltage: 0.001 V

[0504] Charging current: 0.2C (1C = 2600 mA / g)

[0505] Maximum discharging voltage: 2.5 V

[0506] Discharging current: 0.2C (1C = 2600 mA / g)

[0507] Figure 6 is a charge-discharge curve showing the results of the charge-discharge test of Example 1. Figure 7 is a charge-discharge curve showing the results of the charge-discharge test of Comparative Example 1. Figure 6 , 7 Both have the capacity (unit: mAh / g) on the horizontal axis and the applied voltage (unit: V) on the vertical axis. Figure 6 , 7 Any one of them represents the charge-discharge curves from the 1st cycle to the 3rd cycle.

[0508] As shown by Figure 6 , 7As shown, for the battery of Example 1, there were no significant differences in the charge-discharge curves from the 1st cycle to the 3rd cycle. In contrast, for the battery of Comparative Example 1, if charge-discharge was repeated from the 1st cycle to the 3rd cycle, the charge capacity and discharge capacity decreased significantly.

[0509] Figure 8 FIG. is a graph showing the charge-discharge cycle characteristics of Example 1 and Comparative Example 1, and is a graph showing the change in capacity from the 1st cycle to the 10th cycle. Figure 8 The horizontal axis represents the number of cycles, and the vertical axis represents the capacity (unit: mAh / g). As Figure 8 shown, it was confirmed that the battery of Example 1 had a higher capacity retention rate than the battery of Comparative Example 1. For Example 1 using Polymer 1, it is considered that during charge-discharge, anions are fixed by the presence of Polymer 1, and only cations (Li ions) move. Therefore, it is considered that the movement of Li ions is not easily hindered, and the reaction with the negative electrode occurs smoothly. As a result, the physical property difference from Comparative Example 1 is generated as described above.

[0510] <2. Confirmation of the effect of a polymer having the ability to preferentially conduct metal ions (solid electrolyte layer)>

[0511] In this example, in order to confirm the effect in the solid electrolyte layer of a polymer having the ability to preferentially conduct metal ions, the cycle characteristics were confirmed for the following Example 2 and Comparative Example 2 in which only the composition of the solid electrolyte layer was changed.

[0512] [Example 2]

[0513] (Fabrication of lithium ion secondary battery)

[0514] A lithium ion secondary battery of Example 2 was fabricated by operating in the same manner as in Comparative Example 1 except that Polymer 1 contained in the electrolyte was changed to Polymer 2.

[0515] The mixture of P-C material, conductive material, binder, and Polymer 2 corresponds to the "negative electrode material" in the present invention.

[0516] The laminate of the negative electrode, counter electrode, and electrolyte fabricated using the negative electrode material containing Polymer 2 corresponds to the "laminate" in the present invention.

[0517] The battery obtained by accommodating the laminate in an R2032 coin battery case corresponds to the "battery" in the present invention.

[0518] [Comparative Example 2]

[0519] (Fabrication of lithium ion secondary battery)

[0520] The negative electrode 2, counter electrode, electrolyte, and separator were combined to fabricate the lithium ion secondary battery (coin-type battery R2032) of Comparative Example 2. The battery assembly was carried out inside a glove box under an argon atmosphere.

[0521] As the counter electrode, a lithium metal foil was used.

[0522] As the electrolyte, a mixed solution obtained by adding 10 mass% fluoroethylene carbonate (FEC) to a LiPF 6 solution (manufactured by KISHIDA CHEMICAL CO., LTD.) was used. As the LiPF 6 solution, a solution obtained by dissolving LiPF in a mixed solvent in which ethylene carbonate (EC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) were set at a volume ratio of 30:35:35 so as to be 1 mol / L was used. 6

[0523] Figure 9 is a charge-discharge curve showing the results of the charge-discharge tests of Example 2 and Comparative Example 2, and is a graph showing the change in capacity from the 1st cycle to the 10th cycle. Figure 9 The horizontal axis represents the number of cycles, and the vertical axis represents the coulombic efficiency (unit: %). As Figure 9 shown in, the cycle retention rate of the battery of Example 2 was greatly improved compared to the battery of Comparative Example 2 using the conventional electrolyte.

[0524] It is considered that, compared to Comparative Example 2 using an electrolyte, in Example 2 using a polymer having the ability to preferentially conduct metal ions, anions are fixed during charge and discharge, and only cations (Li ions) move. Therefore, it is considered that the movement of Li ions is not easily hindered, and the reaction with the negative electrode occurs smoothly, and as a result, the physical property difference from Comparative Example 2 is generated as described above.

[0525] It is considered that the above results are due to the use of the phosphorus-carbon composite material as the negative electrode active material, but if the above polymer is used, the same tendency of results can be obtained even when a known negative electrode active material is used as the negative electrode active material.

[0526] From the above, it can be confirmed that the present invention is useful.

[0527] Explanation of symbols

[0528] 50... particles, 51... core particles, 52... carbon film, 100... laminate, 120... negative electrode, 121... negative electrode active material layer, 130... solid electrolyte layer

Claims

1. A battery, comprising: a negative electrode having a negative electrode active material layer, and a solid electrolyte layer in contact with the negative electrode active material layer, the negative electrode active material layer containing a negative electrode active material that intercalates or deintercalates ions of an alkali metal when an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied, either or both of the negative electrode active material layer and the solid electrolyte layer containing a polymer having the ability to preferentially conduct metal ions.

2. The battery according to claim 1, wherein both the negative electrode active material layer and the solid electrolyte layer contain the polymer.

3. The battery according to claim 1 or 2, wherein the negative electrode active material is a phosphorus-carbon composite material containing a phosphorus atom and a carbon atom.

4. The battery according to claim 3, wherein the content rate of phosphorus atoms in the phosphorus-carbon composite material is 10% by mass or more and 95% by mass or less, the content rate of carbon atoms in the phosphorus-carbon composite material is 5% by mass or more and 90% by mass or less, The weight loss rate WL at a measurement temperature of 620°C determined by thermogravimetric measurement under the following conditions 620 and the weight loss rate WL at a measurement temperature of 780°C 780 The ratio WL 620 / WL 780 is 0.1 or more and 0.9 or less, (Thermogravimetric measurement) Precisely weigh 10 mg of the phosphorus-carbon composite material as a sample, and using a thermogravimetric measurement device, measure the weight change when heating from 50 °C to 780 °C at a heating rate of 10 °C / minute in a nitrogen gas stream. (Weight reduction rate) Take the ratio of the weight of the sample at the measurement temperature to the weight of the precisely weighed sample as the weight reduction rate (%) at the measurement temperature.

5. The battery according to claim 4, wherein The weight loss rate WL at a measurement temperature of 300°C obtained by the thermogravimetric measurement 300 and the weight loss rate WL at a measurement temperature of 600°C 600 The ratio WL 300 / WL 600 is -0.1 or more and 0.1 or less.

6. The battery according to claim 4, wherein in the XPS spectrum, there is a peak indicating a bond between a phosphorus atom and a carbon atom.

7. The battery according to claim 4, wherein In the XRD distribution measured using CuKα rays, the intensity I at 2θ = 20° 20 , the intensity I at 2θ = 26.3° 26.3 and the intensity I at 2θ = 40° 40 satisfy the following formulas (1) to (3), |P| / |B| < 2 (1) P = I 26.3 -I 40 (2) B=(I 20 -I 40 )×(26.3 - 40) / (20 - 40) (3).

8. The battery according to claim 4, wherein it has: nuclear particles containing phosphorus atoms, and a carbon film covering the surface of the nuclear particles.

9. The battery according to claim 1, wherein the polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capturing ability.

10. The battery according to claim 9, wherein the anionic functional group has at least one of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, and a conjugated anion of a phenolic hydroxyl group.

11. The battery according to claim 9 or 10, wherein the functional group having an anion capturing ability has Lewis acidity.

12. A negative electrode material, wherein it contains: a negative electrode active material, and a polymer having the ability to preferentially conduct metal ions, the negative electrode active material intercalating or deintercalating ions of an alkali metal when an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied.

13. A laminate, comprising: a negative electrode having a negative electrode active material layer, and a solid electrolyte layer in contact with the negative electrode active material layer, the solid electrolyte layer containing a polymer having the ability to preferentially conduct metal ions, the negative electrode active material contained in the negative electrode active material layer intercalating or deintercalating ions of an alkali metal when an alkali metal is used as a counter electrode and a voltage of 0.1 V or more is applied.

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