Electrode composition, secondary battery electrode, secondary battery, and production method for secondary battery

Abstract

According to the present invention, an electrode composition for a secondary battery electrode layer contains an electrolyte solution and satisfies all of (1)–(7). (1) The electrode composition contains an active material and an additive but does not include a binder resin. (2) The additive contains a compound (A), and the compound (A) content is 0.01–2.0 wt% relative to the solid weight of the electrode composition. (3) The HSP distance (Ra_Act) between the compound (A) and the active material is no more than 12.0 MPa0.5. (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte solution is no more than 14.0 MPa0.5. (5) The compound (A) has a polyoxyethylene group that has at least 3 repeats. (6) The additive contains a compound (B) that has one diethylene glycol group and / or a compound (C) that has one ethylene glycol group. (7) The compound (B) content (B_cont) (ppm) and the compound (C) content (C_cont) (ppm) relative to the solid weight of the electrode composition satisfy all of expressions (i)–(iv).　(i) 0≤B_cont≤50. (ii) 0≤C_cont≤10. (iii) 0<B_cont+C_cont≤50. (iv) 20≤B_cont when 0≤C_cont<0.5, 15≤B_cont when 0.5≤C_cont<1.5, 7≤B_cont when 1.5≤C_cont<2.5, 5≤B_cont when 2.5≤C_cont<4.5, and 0≤B_cont when 4.5≤C_cont.

Description

Electrode composition, electrode for secondary battery, secondary battery, and method for manufacturing secondary battery

[0001] The present invention relates to an electrode composition, an electrode for a secondary battery, a secondary battery, and a method for producing a secondary battery.

[0002] Secondary batteries such as lithium-ion batteries are being used in practical applications such as mobile phones, laptop computers, and other portable devices, as well as in hybrid and electric vehicles. To further popularize these devices, there is a demand for higher capacity and power output secondary batteries, and various technologies are being developed to address this demand.

[0003] One way to improve the capacity of secondary batteries is to increase electrode density. By densely packing the active material, more capacity can be obtained. However, increasing electrode density makes it difficult for the electrolyte to penetrate the electrode, resulting in problems such as less capacity than the theoretical value and a deterioration in output characteristics.

[0004] To solve these problems, Patent Document 1 discloses a technique for improving electrolyte permeability by providing grooves on the electrode surface. Patent Document 2 discloses a technique for improving electrolyte permeability by adjusting the particle size and shape of the active material. Furthermore, Patent Document 3 discloses a technique for improving electrolyte permeability by adjusting the electrode density.

[0005] JP 2008-27633 A JP 2012-151088 A JP 2020-053282 A

[0006] However, the method of Patent Document 1 involves a step of pressing the electrode surface with a roller having an uneven surface to form grooves, which necessitates the introduction of new equipment. Furthermore, the methods of Patent Documents 2 and 3 show some improvement in permeability, but the effect is not sufficient. Furthermore, there is a need for further improvement in the capacity retention rate, which is one of the performance features of secondary batteries.

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electrode composition that can be used to produce an electrode with excellent electrolyte permeability and a secondary battery with a high capacity retention rate.

[0008] The present inventors have arrived at the present invention as a result of extensive research. The present invention relates to any one of the following: An electrode composition for a secondary battery electrode layer containing an electrolytic solution, the electrode composition satisfying all of the following (1) to (7): (1) containing an active material and an additive, but not containing a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the weight of the solid content of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa or less; ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５ (5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0009] An electrode composition for a secondary battery electrode layer containing an electrolytic solution, the electrode composition satisfying all of the following (1) to (7): (1) containing an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0010] A secondary battery electrode formed by compression molding the electrode composition. A secondary battery comprising the secondary battery electrode.

[0011] A secondary battery including a current collector layer, a secondary battery electrode layer, and a separator layer, which satisfies all of the following (1) to (7): (1) the secondary battery electrode layer includes an electrode composition containing an active material and an additive and not containing a binder resin, and an electrolyte; (2) the additive includes a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0012] A secondary battery including a current collector layer, a secondary battery electrode layer, and a separator layer, which satisfies all of the following (1) to (7): (1) the secondary battery electrode layer includes an electrode composition containing an active material, a binder resin, and an additive, and an electrolyte; (2) the additive includes a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0013] A method for producing a secondary battery, comprising a step of permeating an electrolytic solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolytic solution is contained in the electrode composition layer, the method satisfying all of the following (1) to (7): (1) the electrode composition layer contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0014] A method for producing a secondary battery, comprising a step of permeating an electrolytic solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolytic solution is contained in the electrode composition layer, the method satisfying all of the following (1) to (7): (1) the electrode composition layer contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0015] According to the present invention, it is possible to provide an electrode composition that can be used to produce an electrode having excellent electrolyte permeability and a secondary battery having a high capacity retention rate.

[0016] [Electrode Composition] The electrode composition of the present invention includes a first type electrode composition and a second type electrode composition. The first type electrode composition is an electrode composition for a secondary battery electrode layer containing an electrolytic solution, and satisfies all of the following (1) to (7): (1) it contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５(5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0017] The electrode composition of the second embodiment is an electrode composition for a secondary battery electrode layer containing an electrolytic solution, and satisfies all of the following (1) to (7): (1) it contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５(5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0018] The electrode composition of the first embodiment and the electrode composition of the second embodiment differ in the following respects, but are common in other respects. The electrode composition of the first embodiment does not contain a binder resin in (1). The electrode composition of the second embodiment contains a binder resin in (1). Below, the common points between the electrode compositions of the first embodiment and the second embodiment will be explained.

[0019] The electrode composition of the present invention is an electrode composition for a secondary battery electrode layer containing an electrolyte solution. The electrode composition of the present invention does not itself contain an electrolyte solution, and by adding an electrolyte solution to the electrode composition, a secondary battery electrode layer can be formed. The electrode composition contains an active material and an additive. The electrode composition of the present invention may be an electrode composition for a lithium ion battery or an electrode composition for a sodium ion battery.

[0020] (Active Material) The active material may be a positive electrode active material or a negative electrode active material.

[0021] The positive electrode active material constituting the electrode composition for lithium ion batteries is a composite oxide of lithium and a transition metal {composite oxide containing one type of transition metal (LiCoO ２ , LiNiO ２ , LiAlMnO４ , LiMnO ２ and LiMn ２ O ４ etc.), composite oxides containing two transition metal elements (e.g., LiFeMnO ４ , LiNi １－ｘ Co ｘ O ２ , LiMn １－ｙ Co ｙ O ２ , LiNi １／３ Co １／３ Al １／３ O ２ and LiNi ０．８ Co ０．１５ Al ０．０５ O ２ ) and composite oxides containing three or more transition metal elements [e.g., LiM ａ M' ｂ M'' ｃ O ２ (M, M', and M'' are different transition metal elements, and a + b + c = 1 is satisfied. For example, LiNi ０．８ Co ０．１ Mn ０．１ O ２ , LiNi １／３ Mn １／３ Co １／３ O ２ ) etc.}, lithium-containing transition metal phosphates (e.g., LiFePO ４ , LiCoPO ４ , LiMnPO ４ and LiNiPO ４ ), transition metal oxides (e.g., MnO ２ and V ２ O ５ ), transition metal sulfides (e.g., MoS ２ and TiS ２ ) and conductive polymers (for example, polyaniline, polypyrrole, polythiophene, polyacetylene, poly-p-phenylene, and polyvinylcarbazole), and two or more of them may be used in combination. Note that the lithium-containing transition metal phosphate may be one in which part of the transition metal site is substituted with another transition metal.

[0022] The positive electrode active material constituting the electrode composition for a sodium ion battery is not particularly limited as long as it can be used in a sodium ion battery. Specific examples include layered active materials, spinel-type active materials, and oxoacid salt active materials. For example, NaFeO ２ , NaNiO ２ , NaCoO ２ , NaCrO ２ , NaMnO ２ , NaVO ２ , Na(Ni Ｘ Mn １－Ｘ ) O ２ (0<X<1), Na(Fe Ｘ Mn １－Ｘ ) O ２ (0<X<1), NaVPO ４ F, Na ２ FePO ４ F, Na ３ V ２ (P.O. ４ ) ３ etc. Preferably, NaCoO ２ and NaCrO ２ is.

[0023] Examples of the negative electrode active material constituting the electrode composition for lithium ion batteries include carbon-based materials [graphite (graphite, artificial graphite, natural graphite), non-graphitizable carbon (hard carbon), amorphous carbon, burned resins (e.g., phenolic resins, furan resins, etc., which are burned and carbonized), cokes (e.g., pitch coke, needle coke, petroleum coke, etc.), and carbon fibers], silicon-based materials [silicon, silicon oxide (SiO ｘ), silicon-carbon composites (carbon particles whose surfaces are coated with silicon and / or silicon carbide, silicon particles or silicon oxide particles whose surfaces are coated with carbon and / or silicon carbide, and silicon carbide, etc.) and silicon alloys (silicon-aluminum alloys, silicon-lithium alloys, silicon-nickel alloys, silicon-iron alloys, silicon-titanium alloys, silicon-manganese alloys, silicon-copper alloys, silicon-tin alloys, etc.), conductive polymers (e.g., polyacetylene and polypyrrole), metals (tin, aluminum, zirconium, titanium, etc.), metal oxides (titanium oxide and lithium-titanium oxide, etc.), metal alloys (e.g., lithium-tin alloys, lithium-aluminum alloys, lithium-aluminum-manganese alloys, etc.), and mixtures of these with carbon-based materials. When the electrode active material is a negative electrode active material, artificial graphite or natural graphite is preferably used as the negative electrode active material. When the negative electrode active material is graphite, the shape is not particularly limited, and examples include spherical graphite and scaly graphite.

[0024] As the negative electrode active material constituting the electrode composition for a sodium-ion battery, the carbon-based material, silicon-based material, conductive polymer, metal, metal oxide, and metal alloy exemplified as the negative electrode active material constituting the electrode composition for a lithium-ion battery can be used. However, among the materials exemplified above, the lithium-containing material can be replaced with a material containing sodium. Specific examples include a silicon-sodium alloy, sodium-titanium oxide, a sodium-tin alloy, a sodium-aluminum alloy, and a sodium-aluminum-manganese alloy.

[0025] Among the particles of the negative electrode active material, those that do not contain lithium, lithium ions, sodium, or sodium ions inside may be subjected to a pre-doping treatment in which lithium, lithium ions, sodium, or sodium ions are contained in part or all of the particles of the negative electrode active material in advance.

[0026] The content of the active material in the electrode composition is not particularly limited, but from the viewpoint of increasing the electrode density and thereby increasing the battery capacity, a high content of the active material is preferred, and the content is preferably 90 to 95 wt % based on the weight of the solid content of the electrode composition.

[0027] In this specification, the solids weight of the electrode composition means the weight of the materials excluding volatile components such as organic solvents (the total weight of the active material, binder resin, additives, and, if contained, conductive additives, etc.) Specifically, the weight of the residue when the electrode composition is heated at 100°C for 8 hours is defined as the solids weight of the electrode composition.

[0028] (Additive) The additive satisfies the following conditions: (2) The additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) The HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0029] The additive contains compound (A) and further contains compound (B) and / or compound (C). Compound (A), compound (B) and compound (C) will be described below.

[0030] "Compound (A)" The content of compound (A) is 0.01 to 2.0 wt% based on the weight of the solid content of the electrode composition. When the content of compound (A) is within this range, the effects of including compound (A) can be suitably exhibited.

[0031] The compound (A) is a compound that satisfies the following condition: (3) The HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５ (5) Compound (A) has a polyoxyethylene group having a repeating number of 3 or more.

[0032] The HSP distance is determined from the Hansen solubility parameter (HSP value) for two substances for which the HSP distance is to be determined. The HSP value is an index that takes into account the polarity of physical properties by dividing the Hildebrand solubility parameter (SP value) into three components: the dispersion force term δD, the polar term δP, and the hydrogen bond term δH. ２ = δD ２ +δP ２ +δH ２ The HSP distance between two substances is expressed by the following formula, where δD, δP, and δH of the two substances are (δD1, δP1, δH1) and (δD2, δP2, δH2), respectively. HSP distance = SQRT(4 x (δD1 - δD2) ２ + (δP1-δP2) ２ + (δH1-δH2) ２ ) HSP distance refers to the distance between two points when the HSP value is considered as a coordinate in three-dimensional space, and the smaller the HSP distance (the closer the HSP values ​​are), the more easily the two substances will dissolve.

[0033] The HSP value of a substance can be calculated by inputting the structural formula into HSPiP (Hansen Solubility Parameters in Practice) software. Alternatively, values ​​in the HSPiP database or literature values ​​may be used.

[0034] In addition to these methods, HSP values ​​can also be determined experimentally. A target component is dispersed in a solvent with a known HSP value, and the dispersibility of the component in that specific solvent is evaluated. To evaluate dispersibility, the target component for which HSP is to be determined is dispersed in the solvent, the absorption spectrum is measured, and the absorbance values ​​are recorded at 10-second intervals for 20 minutes (measurement wavelength: 632 nm). The dispersion index (DISP) is calculated by dividing the absorbance at 20 minutes by the absorbance at the start of measurement. The obtained dispersion index is used to evaluate dispersibility in each solvent based on the following evaluation criteria: 1: DISP = 0.30 or more; 2: DISP = 0.20 or more but less than 0.30; 3: DISP = 0.15 or more but less than 0.20; 4: DISP = 0.10 or more but less than 0.15; 5: DISP = less than 0.10. The HSP value of the target component can be calculated by inputting the evaluation results of dispersibility in each solvent into HSPiP.

[0035] The solvent used in the method for determining the HSP value described above can be any solvent with a known HSP value, and can be any solvent selected from the group consisting of toluene, N-methylpyrrolidone (NMP), diethyl carbonate, dimethylformamide, 1,4-dioxane, hexane, cyclohexane, methanol, ethanol, acetone, acetonitrile, and methyl ethyl ketone (MEK).

[0036] The HSP values ​​of the active material and compound (A) constituting the electrode composition are determined, and the HSP distance between compound (A) and the active material is determined from the HSP values ​​(more precisely, δD, δP, and δH of the active material and compound (A) respectively). The electrode composition of the present invention has an HSP distance (Ra_Act) between compound (A) and the active material of 12.0 MPa. ０．５ The HSP distance between the compound (A) and the active material is 4.0 MPa. ０．５ It is preferable that the HSP distance between the compound (A) and the active material is 4.0 MPa or more. ０．５ If the HSP distance is less than 1 / 2 mm (if the HSP distance between compound (A) and the active material is small), the compatibility between compound (A) and the active material is high, and the surface of the active material may be corroded by compound (A), making the electrode layer brittle when used as an electrode layer.

[0037] Although the electrolyte is not a component of the electrode composition, the electrode composition contains the electrolyte and is used as a secondary battery electrode layer, and the HSP distance between the compound (A) and the electrolyte is determined in relation to the electrolyte contained in the electrode composition. The HSP values ​​of the compound (A) and the electrolyte are determined, and the HSP distance between the compound (A) and the electrolyte is determined from the HSP values ​​(more precisely, δD, δP, and δH of the compound (A) and the electrolyte, respectively). The electrode composition of the present invention has a (Ra_Elec) between the compound (A) and the electrolyte of 14.0 MPa. ０．５ The HSP distance between the compound (A) and the electrolyte is 12.0 MPa. ０．５ The lower limit of the HSP distance between the compound (A) and the electrolyte is not particularly limited, but is preferably 1.0 MPa or less. ０．５ It is preferable that this is equal to or greater than this.

[0038] Compound (A) satisfies requirements (3) and (4) regarding the HSP distance, and is also a compound that "has three or more repeating polyoxyethylene groups" as requirement (5). Compound (A) can be one selected from the group consisting of an ethylene oxide adduct of alkyl alcohol, an ethylene oxide adduct of (di)ethylene glycol, and a polyethylene glycol (di)alkyl ether.

[0039] The following compounds are designated as compounds (A1) to (A3): (A1) Ethylene oxide adduct of alkyl alcohol (A2) Ethylene oxide adduct of (di)ethylene glycol (A3) Polyethylene glycol (di)alkyl ether

[0040] (A1) Ethylene oxide adduct of alkyl alcohol Hereinafter, ethylene oxide may be abbreviated as EO.

[0041] The average number of moles of ethylene oxide added in the ethylene oxide adduct of alkyl alcohol is 3 or more. The average number of moles of ethylene oxide added may be 3 to 20, or may be 4 to 10.

[0042] The alkyl alcohol constituting the alkyl alcohol ethylene oxide adduct is preferably a saturated alkyl alcohol from the viewpoint of suppressing deterioration of battery performance due to side reactions that may occur during charging and discharging. The alkyl group of the alkyl alcohol may be linear or branched.

[0043] The number of carbon atoms in the alkyl group of the alkyl alcohol is not particularly limited, and is preferably 1 to 20. Examples of alkyl alcohols having 1 to 20 carbon atoms include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, 2-ethylhexanol, isodecanol, and isotridecanol.

[0044] Specific examples of ethylene oxide adducts of alkyl alcohols include heptaethylene glycol monoisodecyl ether, tetraethylene glycol monopentadecyl ether, nonaethylene glycol monododecyl ether, and nonaethylene glycol monomethyl ether.

[0045] (A2) Ethylene oxide adduct of (di)ethylene glycol (A2) is a polyethylene glycol having a polyoxyethylene group repeat number of 3 or more. The polyoxyethylene group repeat number may be 3 to 20, or may be 4 to 10. Specific examples of the ethylene oxide adduct of (di)ethylene glycol include tetraethylene glycol (polyoxyethylene group repeat number: 4) and octaethylene glycol (polyoxyethylene group repeat number: 8).

[0046] (A3) Polyethylene glycol (di)alkyl ether The number of repeating polyoxyethylene groups in the polyethylene glycol moiety is 3 or more. The number of repeating polyoxyethylene groups is preferably 3 to 20, and may be 4 to 15. A specific example of the polyethylene glycol (di)alkyl ether is triethylene glycol dimethyl ether.

[0047] "Compound (B) and Compound (C)" Compound (B) is a compound having one diethylene glycol group, and compound (C) is a compound having one ethylene glycol group. If compound (B) and compound (C) satisfy the requirements for the number of diethylene glycol groups or the number of ethylene glycol groups, they can be considered as compound (B) and compound (C) regardless of the structure of other parts.

[0048] Examples of compound (B) include diethylene glycol (di)alkyl ether and diethylene glycol. The number of carbon atoms in the alkyl group of diethylene glycol (di)alkyl ether is not particularly limited, and is preferably 1 to 20. Specific examples of compound (B) include diethylene glycol monoisodecyl ether, diethylene glycol monopentadecyl ether, diethylene glycol monododecyl ether, diethylene glycol monomethyl ether, diethylene glycol, and diethylene glycol dimethyl ether.

[0049] Examples of compound (C) include ethylene glycol (di)alkyl ether and ethylene glycol. The number of carbon atoms in the alkyl group of the ethylene glycol (di)alkyl ether is not particularly limited, and is preferably 1 to 20. Specific examples of compound (C) include ethylene glycol monoisodecyl ether, ethylene glycol monopentadecyl ether, ethylene glycol monododecyl ether, ethylene glycol monomethyl ether, ethylene glycol, and ethylene glycol dimethyl ether.

[0050] Compound (B) and compound (C) may have the same structure as compound (A) contained in the additive, except for the number of repeats of the polyoxyethylene group. That is, compound (B) and / or compound (C) contained in the additive together with compound (A) may have two or one polyoxyethylene group in the polyoxyethylene group portion having three or more repeats of compound (A). Furthermore, compound (B) and compound (C) may have a different structure from compound (A) contained in the additive, except for the number of repeats of the polyoxyethylene group.

[0051] Examples of combinations of compound (A), compound (B), and compound (C) are as follows: (Example 1) When compound (A) is heptaethylene glycol monoisodecyl ether, compound (B) is diethylene glycol monoisodecyl ether, and compound (C) is ethylene glycol monoisodecyl ether. (Example 2) When compound (A) is tetraethylene glycol monopentadecyl ether, compound (B) is diethylene glycol monopentadecyl ether, and compound (C) is ethylene glycol monopentadecyl ether. (Example 3) When compound (A) is nonaethylene glycol monododecyl ether, compound (B) is diethylene glycol monododecyl ether, and compound (C) is ethylene glycol monododecyl ether. (Example 4) When compound (A) is nonaethylene glycol monomethyl ether, compound (B) is diethylene glycol monomethyl ether, and compound (C) is ethylene glycol monomethyl ether.

[0052] (Example 5) When compound (A) is polyethylene glycol, compound (B) is diethylene glycol and compound (C) is ethylene glycol. (Example 6) When compound (A) is triethylene glycol dimethyl ether, compound (B) is diethylene glycol dimethyl ether and compound (C) is ethylene glycol dimethyl ether. (Example 7) When compound (A) is heptaethylene glycol monoisodecyl ether, compound (B) is diethylene glycol monomethyl ether and compound (C) is ethylene glycol monomethyl ether.

[0053] The content of compound (B) (B_cont, unit: ppm) based on the solid content weight of the electrode composition and the content of compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont (i) specifies the range of B_cont (lower and upper limits), and (ii) specifies the range of C_cont (lower and upper limits). (iii) specifies the range of the total amount of B_cont and C_cont (lower and upper limits). (iv) defines the range of B_cont that can be taken by corresponding to the range of C_cont, which is divided into five stages.

[0054] By including compound (A) in the additive contained in the electrode composition, an electrode with excellent electrolyte permeability can be obtained. Furthermore, when the additive contained in the electrode composition contains compound (B) and / or compound (C) and the content is such that the values ​​of B_cont and C_cont satisfy all of the relationship formulas (i) to (iv) shown in requirement (7), the effect of improving the capacity retention rate can be exhibited compared to when the additive contains only compound (A). As a result, the electrode composition of the present invention can be used to produce an electrode with excellent electrolyte permeability and a secondary battery with a high capacity retention rate.

[0055] (Electrolyte) As the electrolyte, an electrolyte for a secondary battery can be used, and an electrolyte containing a non-aqueous solvent that can be used for a lithium ion battery or a sodium ion battery can be preferably used. The electrolyte has an HSP distance (Ra_Elec) between the compound (A) contained in the electrode composition and the non-aqueous solvent of 14.0 MPa. ０．５ Use the following:

[0056] The solvent contained in the electrolytic solution can be a non-aqueous solvent used in known electrolytic solutions, such as a lactone compound, a cyclic or chain carbonate ester, a chain carboxylic acid ester, a cyclic or chain ether, a phosphate ester, a nitrile compound, an amide compound, a sulfone, a sulfolane, or a mixture thereof.

[0057] Examples of lactone compounds include lactone compounds having a five-membered ring (such as γ-butyrolactone and γ-valerolactone) and a six-membered ring (such as δ-valerolactone).

[0058] Examples of cyclic carbonates include propylene carbonate (PC), ethylene carbonate (EC), and butylene carbonate (BC). Examples of chain carbonates include dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl-n-propyl carbonate, ethyl-n-propyl carbonate, and di-n-propyl carbonate.

[0059] Examples of the chain carboxylic acid ester include methyl acetate, ethyl acetate, propyl acetate, and methyl propionate.

[0060] Examples of cyclic ethers include tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, and 1,4-dioxane. Examples of chain ethers include dimethoxymethane and 1,2-dimethoxyethane.

[0061] Examples of phosphate esters include trimethyl phosphate, triethyl phosphate, ethyl dimethyl phosphate, diethylmethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(trifluoromethyl phosphate), tri(trichloromethyl phosphate), tri(trifluoroethyl phosphate), 2-ethoxy-1,3,2-dioxaphospholan-2-one, 2-trifluoroethoxy-1,3,2-dioxaphospholan-2-one, and 2-methoxyethoxy-1,3,2-dioxaphospholan-2-one.

[0062] Examples of nitrile compounds include acetonitrile, etc. Examples of amide compounds include DMF, etc. Examples of sulfones include dimethyl sulfone and diethyl sulfone, etc.

[0063] These solvents may be used alone or in combination of two or more. The mixed solvent is preferably a mixed solvent of ethylene carbonate and diethyl carbonate, a mixed solvent of ethylene carbonate, ethyl methyl carbonate and diethyl carbonate, or a mixed solvent of ethylene carbonate and propylene carbonate.

[0064] The electrolyte contained in the electrolytic solution can be any electrolyte used in known electrolytic solutions. For example, a lithium salt can be used in the case of a lithium ion battery, and a sodium salt can be used in the case of a sodium ion battery. Examples of the lithium salt include LiPF ６ , LiBF ４ , LiSbF ６ , LiAsF ６ , LiClO ４ and LiN(FSO ２ ) ２ Lithium salts of inorganic anions such as LiN(CF ３ SO ２ ) ２ , LiN(C ２ F ５ SO ２ ) ２ and LiC(CF ３ SO ２ ) ３ Among these, LiPF ６ (lithium hexafluorophosphate), LiFSI (lithium bis(fluorosulfonyl)imide), etc. can be preferably used. Examples of sodium salts include NaPF ６ , NaBF ４ , NaClO ４ and NaAsF ６ inorganic sodium salts such as; and NaCF ３ SO ３ , NaN(CF ３ SO ２ ) ２ , NaN(C２ F ５ SO ２ ) ２ , NaN(FSO ２ ) ２ , NaC(CF ３ SO ２ ) ３ Among these, preferred from the viewpoint of battery output and charge / discharge cycle characteristics is NaPF ６ is.

[0065] The concentration of the electrolyte in the electrolytic solution is not particularly limited, but is preferably 0.3 to 5.0 mol / L, more preferably 0.5 to 2.0 mol / L, and even more preferably 0.8 to 1.5 mol / L.

[0066] Since the HSP value of an electrolyte solution largely depends on the type of solvent, the HSP value can be calculated based on the type of solvent without considering the influence of the electrolyte. When a mixed solvent is used as the solvent, the average of the HSP values ​​of each solvent (δD, δP, and δH) based on the volume ratio of each solvent is used as each term of the HSP value of the mixed solvent.

[0067] (Binder Resin) The electrode composition of the first embodiment does not contain a binder resin, while the electrode composition of the second embodiment contains a binder resin. The binder resin will be explained below. The compound (A) having a polyoxyethylene group with a repeating number of 3 or more, the compound (B) having one diethylene glycol group, and the compound (C) having one ethylene glycol group are not considered to be binder resins.

[0068] The binder resin is a resin used in lithium ion batteries or sodium ion batteries, and examples thereof include starch, polyvinylidene fluoride, polyvinyl alcohol, polyvinylpyrrolidone, polytetrafluoroethylene, styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyethylene, polypropylene, etc. When the electrode composition contains these substances, it is considered to contain a binder resin.

[0069] The binder resin may have a weight average molecular weight (Mw) of more than 50,000. The weight average molecular weight of the binder resin can be measured by gel permeation chromatography, for example, under the following conditions. Apparatus: "Waters Alliance 2695" [manufactured by Waters] Column: "Guard column Super H-L" (1 column), "TSKgel Super H2000, TSKgel Super H3000, TSKgel Super H4000 (all manufactured by Tosoh Corporation) connected together (one column each)" Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection amount: 10 μl Flow rate: 0.6 ml / min Measurement temperature: 40°C Detector: refractive index detector Reference material: standard polyethylene glycol

[0070] On the other hand, the electrode composition of the second embodiment contains a binder resin. When the electrode composition contains a binder resin, the content of the binder resin is preferably more than 0 wt % and not more than 6.0 wt % based on the solid content weight of the electrode composition.

[0071] The electrode composition of the present invention may contain a conductive additive. Examples of the conductive additive include metals (aluminum, stainless steel (SUS), silver, gold, copper, titanium, etc.), carbon (graphite (flaky graphite (UP)), carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), and carbon nanofibers (CNF), etc.), and mixtures thereof. Acetylene black is preferred as the conductive additive. Note that carbon-based materials are used as both negative electrode active materials and conductive additives. In this application, materials with a volume average particle diameter of 10.0 μm or more are considered negative electrode active materials, and materials with a volume average particle diameter of less than 10.0 μm are considered conductive additives.

[0072] The electrode composition of the present invention has an HSP distance between the active material and the compound (A) of 12.0 MPa. ０．５ Since the HSP distance between the compound (A) and the electrolyte is 14.0 MPa or less, the active material and the compound (A) are intimately compatible with each other, and the surface of the active material is in a state where it is surface-treated with an additive containing the compound (A).０．５ The following formula specifies that compound (A) and the electrolyte have a good compatibility relationship. Therefore, the electrolyte can easily penetrate into the electrode composition. Therefore, the electrode composition of the present invention is an electrode composition that can be used to produce an electrode with excellent electrolyte permeability. Furthermore, the electrode composition of the present invention is excellent in electrolyte permeability even when the electrode density is increased, and therefore is an electrode composition that can be used to produce high-energy density electrodes without reducing production capacity.

[0073] Furthermore, the HSP distance between the active material and the compound (A) is 4.0 MPa. ０．５ If the above is the case, an electrode composition can be obtained that can produce an electrode having good properties in terms of electrode brittleness.

[0074] [Secondary Battery Electrode and Secondary Battery] The secondary battery electrode of the present invention is an electrode for a secondary battery obtained by compression molding the electrode composition of the present invention. As the electrode composition of the present invention, either the electrode composition of the first form or the electrode composition of the second form may be used. The method for compression molding the electrode composition is not particularly limited, but methods such as roll pressing and pressing with a press machine can be used. The electrode density of the secondary battery electrode obtained by compression molding the electrode composition is 1.0 to 2.0 g / cm ３ It is preferable that the electrode density defined here means the density in a state where the electrolyte solution has not been impregnated into the electrode composition. Furthermore, a secondary battery comprising the above-described secondary battery electrode of the present invention is also the secondary battery of the present invention. In this secondary battery of the present invention, the configuration other than that of the secondary battery electrode of the present invention is not particularly limited.

[0075] [Secondary Battery] The secondary battery of the present invention includes the secondary battery including the secondary battery electrode of the present invention described above, as well as the following first and second types of secondary batteries. The first type of secondary battery corresponds to the electrode composition of the first type, and the second type of secondary battery corresponds to the electrode composition of the second type.

[0076] The secondary battery of the first embodiment is a secondary battery including a current collector layer, a secondary battery electrode layer, and a separator layer, and satisfies all of the following (1) to (7): (1) the secondary battery electrode layer includes an electrode composition containing an active material and an additive, and not containing a binder resin, and an electrolyte; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0077] The secondary battery of the second embodiment is a secondary battery including a current collector layer, a secondary battery electrode layer, and a separator layer, and satisfies all of the following (1) to (7): (1) the secondary battery electrode layer includes an electrode composition containing an active material, a binder resin, and an additive, and an electrolyte; (2) the additive includes a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５(4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0078] The above-mentioned provisions (2) to (7) in the secondary batteries of the first and second embodiments are the same as the provisions (2) to (7) in the electrode composition of the present invention. The secondary batteries of the first and second embodiments include a secondary battery electrode layer. In (1), it is specified that the secondary battery electrode layer contains an electrolytic solution.

[0079] The secondary battery electrode layer is a layer containing an electrolyte solution in the electrode composition of the first and second embodiments. The secondary battery electrode layer can contain a sufficient amount of electrolyte solution in a short time due to the good electrolyte solution permeability of the electrode composition of the first and second embodiments. Because the secondary battery electrode layer can contain a sufficient amount of electrolyte solution in a short time, the secondary batteries of the first and second embodiments can be produced in a short time and can extract a capacity close to the theoretical value.

[0080] Other components of the secondary battery than the secondary battery electrode layer include a current collector layer and a separator layer. As the current collector layer and separator layer, a current collector and separator that can be used in a typical lithium-ion secondary battery or a sodium-ion battery can be used.

[0081] The secondary battery of the present invention can be used as a secondary battery for use in mobile phones, personal computers, hybrid vehicles, electric vehicles, stationary power sources, and the like.

[0082] [Electrolyte Solution Penetration Method] This specification discloses the following electrolyte solution penetration methods, which include the following first and second electrolyte solution penetration methods. The first electrolyte solution penetration method corresponds to the method of permeating the electrode composition of the first type with an electrolyte, and the second electrolyte solution penetration method corresponds to the method of permeating the electrode composition of the second type with an electrolyte.

[0083] The first embodiment of the electrolyte solution penetration method is a method of permeating an electrode composition with an electrolyte solution, and is an electrolyte solution penetration method that satisfies all of the following (1) to (7): (1) the electrode composition contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５(5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0084] The first embodiment of the electrolyte solution penetration method is a method of permeating an electrode composition with an electrolyte solution, and is an electrolyte solution penetration method that satisfies all of the following (1) to (7): (1) the electrode composition contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５(5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0085] In any of the electrolyte solution penetration methods, the means for penetrating the electrode composition with the electrolyte solution is not particularly limited, and any one of a spray coater, a dispenser, a die coater, and a roll coater may be used. Alternatively, after assembling the components constituting the battery, such as the electrode composition, the current collector, and the separator, and sealing them with a sealing member, the electrolyte solution may be injected into the electrode composition through an injection port provided in the sealing member, thereby penetrating the electrode composition with the electrolyte solution.

[0086] In the electrolyte solution penetration method of the present invention, since the electrolyte solution permeability into the electrode composition is good, the work of impregnating the electrode composition with the electrolyte can be completed in a short time, and the workability when obtaining a secondary battery electrode layer is good. The work time (penetration time) for impregnating the electrode composition with the electrolyte solution varies depending on the type of electrolyte solution, the size of the secondary battery, etc., but can be, for example, 300 minutes or less.

[0087] [Method for manufacturing secondary battery] The method for manufacturing a secondary battery of the present invention includes a first embodiment of a method for manufacturing a secondary battery and a second embodiment of a method for manufacturing a secondary battery. The first embodiment of a method for manufacturing a secondary battery corresponds to the method for manufacturing a secondary battery by permeating an electrolyte solution into the electrode composition of the first embodiment, and the second embodiment of an electrolyte solution permeation method corresponds to the method for manufacturing a secondary battery by permeating an electrolyte solution into the electrode composition of the second embodiment.

[0088] A first embodiment of the method for producing a secondary battery includes a step of permeating an electrolytic solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolytic solution is contained in the electrode composition layer, and the method for producing a secondary battery satisfies all of the following (1) to (7): (1) the electrode composition layer contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa or less; ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0089] A second embodiment of the method for producing a secondary battery includes a step of permeating an electrolytic solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolytic solution is contained in the electrode composition layer, and the method for producing a secondary battery satisfies all of the following (1) to (7): (1) the electrode composition layer contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa or less; ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0090] In any of the methods for producing secondary batteries, when obtaining a battery unit, it is preferable to carry out a step of applying an electrode composition to a current collector layer to form an electrode composition layer on the current collector layer, and then drying the electrode composition to obtain an electrode sheet in which the current collector layer and the electrode composition layer are combined. Compounds (B) and (C) contained in the electrode composition volatilize upon drying. Because compounds (B) and (C) have fewer oxyethylene groups added than compound (A), compounds (B) and (C) are more likely to volatilize upon drying than compound (A). If the drying temperature is high, compounds (B) and (C) volatilize in large amounts from the electrode composition, thereby reducing the effect of including compound (B) and / or compound (C) in the electrode composition on improving the capacity retention rate. From this perspective, the drying temperature is preferably 150°C or lower, more preferably 130°C or lower, and even more preferably 110°C or lower. Furthermore, the drying temperature is preferably 70°C or higher.

[0091] In any of the methods for manufacturing a secondary battery, the means for permeating the battery unit including the electrode composition layer with the electrolyte solution is not particularly limited, and any one of a spray coater, a dispenser, a die coater, and a roll coater may be used. When permeating the battery unit with the electrolyte solution, the electrode composition may be permeated with the electrolyte solution to form a secondary battery electrode layer, and then the current collector layer and the separator layer may be combined to form a battery unit including the secondary battery electrode layer. Alternatively, the current collector layer, the electrode composition layer, and the separator layer may be combined, and then the electrode composition layer may be permeated with the electrolyte solution to form a secondary battery electrode layer, to form a battery unit including the secondary battery electrode layer.

[0092] In the method for producing a secondary battery of the present invention, since the electrolyte permeability into the electrode composition is good, the work of permeating the electrolyte into the electrode composition can be completed in a short time, and the workability when obtaining a secondary battery electrode layer is good. The work time (permeation time) for permeating the electrolyte into the electrode composition varies depending on the type of electrolyte, the size of the secondary battery, etc., but can be, for example, 300 minutes or less.

[0093] The present specification discloses the following:

[0094] The present disclosure (1) provides an electrode composition for a secondary battery electrode layer containing an electrolytic solution, which satisfies all of the following (1) to (7): (1) the electrode composition contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; and (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５ (5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0095] The present disclosure (2) provides an electrode composition for a secondary battery electrode layer containing an electrolytic solution, which satisfies all of the following (1) to (7): (1) the electrode composition contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the weight of the solid content of the electrode composition; and (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0096] The present disclosure (3) is the electrode composition according to the present disclosure (1) or (2), wherein the compound (A) is one selected from the group consisting of an ethylene oxide adduct of an alkyl alcohol, an ethylene oxide adduct of (di)ethylene glycol, and a polyethylene glycol (di)alkyl ether.

[0097] The present disclosure (4) is the electrode composition according to any one of the present disclosures (1) to (3), in which the compound (B) is a diethylene glycol (di)alkyl ether.

[0098] The present disclosure (5) is the electrode composition according to any one of the present disclosures (1) to (4), wherein the compound (C) is an ethylene glycol (di)alkyl ether.

[0099] The present disclosure (6) is a method for manufacturing a semiconductor device in which the HSP distance (Ra_Act) between the compound (A) and the active material is 4.0 MPa. ０．５ The electrode composition according to any one of the present disclosures (1) to (5) is as described above.

[0100] The present disclosure (7) is a method for manufacturing a polymer electrolyte membrane having an HSP distance (Ra_Elec) between the compound (A) and the electrolyte solution of 12.0 MPa. ０．５ The electrode composition is described in any one of the following (1) to (6) of the present disclosure.

[0101] The present disclosure (8) is the electrode composition according to any one of the present disclosures (1) to (7), wherein the active material is artificial graphite or natural graphite.

[0102] The present disclosure (9) is the electrode composition according to any one of the present disclosures (1) to (8), wherein the solvent of the electrolytic solution is a mixed solvent of ethylene carbonate and diethyl carbonate, a mixed solvent of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate, or a mixed solvent of ethylene carbonate and propylene carbonate.

[0103] The present disclosure (10) is an electrode for a secondary battery obtained by compression molding the electrode composition according to any one of the present disclosures (1) to (9).

[0104] The present disclosure (11) is a secondary battery including the electrode for a secondary battery according to the present disclosure (10).

[0105] The present disclosure (12) is a secondary battery including a current collector layer, a secondary battery electrode layer, and a separator layer, and the secondary battery satisfies all of the following (1) to (7): (1) the secondary battery electrode layer includes an electrode composition containing an active material and an additive and not containing a binder resin, and an electrolyte solution; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0106] The present disclosure (13) is a secondary battery including a current collector layer, a secondary battery electrode layer, and a separator layer, and the secondary battery satisfies all of the following (1) to (7): (1) the secondary battery electrode layer includes an electrode composition containing an active material, a binder resin, and an additive, and an electrolyte solution; (2) the additive includes a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0107] The present disclosure (14) is a method for producing a secondary battery, which includes a step of permeating an electrolytic solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolytic solution is contained in the electrode composition layer, and which satisfies all of the following (1) to (7): (1) the electrode composition layer contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa or less; ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0108] The present disclosure (15) is a method for producing a secondary battery, which includes a step of permeating an electrolytic solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolytic solution is contained in the electrode composition layer, and which satisfies all of the following (1) to (7): (1) the electrode composition layer contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa or less; ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less. ０．５(5) the compound (A) has a polyoxyethylene group having a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont

[0109] The present disclosure (16) is a method for producing a secondary battery according to the present disclosure (14) or (15), comprising a step of applying an electrode composition to the current collector layer to form an electrode composition layer on the current collector layer, and drying the electrode composition layer at a drying temperature of 150°C or less to obtain an electrode sheet in which the current collector layer and the electrode composition layer are combined.

[0110] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples as long as they do not deviate from the gist of the present invention. Unless otherwise specified, parts mean parts by weight and % means % by weight.

[0111] (Preparation of Compounds (A1) to (A7)) The following compounds (A1) to (A7) were prepared. Compound (A1) An alkylene oxide adduct of an alkyl alcohol produced by adding ethylene oxide (EO) to isodecanol was obtained as compound (a1). The average number of moles of EO added was 7.0. The amount of 2-mol EO adduct contained as a by-product was 515 ppm based on the total weight of compound (a1), and the amount of 1-mol EO adduct contained as a by-product was 160 ppm based on the total weight of compound (a1). The amount of by-products contained in compound (a1) can be measured by HPLC-MS, and any molecular weight region can be selected and extracted. The region of compound (a1) that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS and obtained as compound (A1). 2-mol EO adducts and 1-mol EO adducts were not detected in compound (A1) by HPLC-MS. The compound (A1) is named heptaethylene glycol monoisodecyl ether.

[0112] Compound (A2) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to pentadecyl alcohol was obtained as compound (a2). The average number of moles of EO added was 4.0. The amount of 2-mol EO adduct contained as a by-product was 505 ppm based on the total weight of compound (a2), and the amount of 1-mol EO adduct contained as a by-product was 145 ppm based on the total weight of compound (a2). The region of compound (a2) that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS and obtained as compound (A2). The 2-mol EO adduct and 1-mol EO adduct could not be detected in compound (A2) by HPLC-MS. The chemical name of compound (A2) is tetraethylene glycol monopentadecyl ether.

[0113] Compound (A3) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to dodecanol was obtained as compound (a3). The average number of moles of EO added was 9.0. The amount of 2-mol EO adduct contained as a by-product was 525 ppm based on the total weight of compound (a3), and the amount of 1-mol EO adduct contained as a by-product was 170 ppm based on the total weight of compound (a3). The region of compound (a3) ​​that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS and obtained as compound (A3). The 2-mol EO adduct and 1-mol EO adduct could not be detected in compound (A3) by HPLC-MS. The chemical name of compound (A3) is nonaethylene glycol monododecyl ether.

[0114] Compound (A4) Tetraethylene glycol (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (a4). The region of compound (a4) that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS and obtained as compound (A4). 2-mol EO adducts and 1-mol EO adducts could not be detected in compound (A4) by HPLC-MS.

[0115] Compound (A5) Octaethylene glycol (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (a5). The region of compound (a5) that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS and obtained as compound (A5). 2-mol EO adducts and 1-mol EO adducts could not be detected in compound (A5) by HPLC-MS.

[0116] Compound (A6) Triethylene glycol dimethyl ether (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (a6). The region of compound (a6) that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS and obtained as compound (A6). Neither 2-mol EO adducts nor 1-mol EO adducts were detected in compound (A6) by HPLC-MS.

[0117] Compound (A7) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to methanol was obtained as compound (a7). The average number of moles of EO added was 9.0. The amount of 2-mol EO adduct contained as a by-product was 510 ppm based on the total weight of compound (a7), and the amount of 1-mol EO adduct contained as a by-product was 155 ppm based on the total weight of compound (a7). The region of compound (a7) that did not contain 2-mol EO adducts or 1-mol EO adducts was extracted by HPLC-MS, and compound (A7) was obtained. The 2-mol EO adduct and 1-mol EO adduct could not be detected in compound (A7) by HPLC-MS. The compound is called nonaethylene glycol monomethyl ether.

[0118] (Preparation of Compounds (A8) to (A19)) The following compounds (A8) to (A19) were prepared. Compound (A8): Triethylene glycol (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (A8). Compound (A9): Ethylene glycol monomethyl ether (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (A9). Compound (A10): Trimethylolpropane (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (A10). Compound (A11): N-(hydroxymethyl)methacrylamide (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (A11). Compound (A12): Methyl n-octanoate (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (A12). Compound (A13): Methyl tetradecanoate (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (A13). Compound (A14) Glycerin and stearic acid (molar ratio: 1 / 1) were added to xylene to initiate the esterification reaction (xylene content: 50 wt% of the total). Polymerization was carried out under reflux, and water produced in the esterification reaction was removed together with xylene. The polymerization was continued while adding the removed amount of xylene until no more water was produced. After the reaction, the xylene was removed using a vacuum dryer, and a solid monoglycerin stearate was obtained, which was designated as compound (A14). Compound (A15) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to tribenzylphenol was obtained as compound (A15). The average number of moles of EO added was 6.0, and the compound was designated hexaethylene glycol tribenzyl phenyl ether. Compound (A16) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to tribenzylphenol was obtained as compound (A16). The average number of moles of EO added was 14.0, and the compound was named tetradecaethylene glycol tribenzyl phenyl ether. Compound (A17) Cyclohexylamine (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was named compound (A17). Compound (A18) Tris(2-chloro-1-methylethyl) phosphate (reagent: manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) was named compound (A18). Compound (A19) Hexadecanol (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was named compound (A19).

[0119] (Preparation of Compounds (B1), (B4), (B6), (B7), (C1), (C4), (C6), and (C7)) The following compounds (B1), (B4), (B6), (B7), (C1), (C4), (C6), and (C7) were prepared. Compound (B1) An alkylene oxide adduct of an alkyl alcohol produced by adding ethylene oxide (EO) to isodecanol was obtained as compound (b1). The average number of moles of EO added was 2.0. Compound (B1) was obtained by extracting a region of compound (b1) that did not contain one mole of EO adduct or three or more moles of EO adducts using HPLC-MS. Neither one mole of EO adduct nor three or more moles of EO adducts were detected in compound (B1) by HPLC-MS. The chemical name of compound (B1) is diethylene glycol monoisodecyl ether.

[0120] Compound (B4) Diethylene glycol (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (B4).

[0121] Compound (B6) Diethylene glycol dimethyl ether (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (B6).

[0122] Compound (B7) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to methanol was obtained as compound (b7). The average number of moles of EO added was 2.0. The region that did not contain a 1-mol adduct of compound (b7) or an adduct of 3 or more moles of EO was extracted by HPLC-MS and obtained as compound (B7). No 1-mol EO adduct was detected in compound (B7) by HPLC-MS. The compound name of compound (B7) is diethylene glycol monomethyl ether.

[0123] Compound (C1) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to isodecanol was obtained as compound (c1). The average number of moles of EO added was 1.0. The region containing only the 1 mole EO adduct of compound (c1) was extracted by HPLC-MS and obtained as compound (C1). No adducts containing 2 moles or more of EO were detected in compound (C1) by HPLC-MS. The chemical name of compound (C1) is ethylene glycol monoisodecyl ether.

[0124] Compound (C4) Ethylene glycol (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (C4).

[0125] Compound (C6) Ethylene glycol dimethyl ether (reagent: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound (C6).

[0126] Compound (C7) An alkylene oxide adduct of alkyl alcohol produced by adding ethylene oxide (EO) to methanol was obtained as compound (c7). The average number of moles of EO added was 1.0. The region containing only the 1 mole EO adduct of compound (c7) was extracted by HPLC-MS and obtained as compound (C7). Adducts containing 2 moles or more of EO were not detected in compound (C7) by HPLC-MS. The chemical name of compound (C7) is ethylene glycol monomethyl ether.

[0127] (Preparation of Electrolytes 1 to 5) The following substances were all prepared as reagents (manufactured by Tokyo Chemical Industry Co., Ltd.). (Electrolyte 1) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC = 1:1 to obtain lithium hexafluorophosphate (LiPF ６) was dissolved to a concentration of 1M, and the resulting solution was designated as electrolyte solution 1. (Electrolyte solution 1BC-1i) 2.0% by weight of compound (B1) and 1.0% by weight of compound (C1) were added to electrolyte solution 1 to designate electrolyte solution 1BC-1i. (Electrolyte solution 1BC-1ii) 4.0% by weight of compound (B1) and 2.0% by weight of compound (C1) were added to electrolyte solution 1 to designate electrolyte solution 1BC-1ii. (Electrolyte solution 1BC-7i) 2.0% by weight of compound (B7) and 1.0% by weight of compound (C7) were added to electrolyte solution 1 to designate electrolyte solution 1BC-7i. (Electrolyte solution 1BC-7ii) 4.0% by weight of compound (B7) and 2.0% by weight of compound (C7) were added to electrolyte solution 1 to designate electrolyte solution 1BC-7ii. (Electrolyte 2) Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of EC:EMC:DEC=2:4:4 to obtain lithium hexafluorophosphate (LiPF ６ ) was dissolved to a concentration of 1 M to prepare electrolyte solution 2. (Electrolyte solution 3) Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of EC:EMC:DEC = 3:5:2 to prepare lithium hexafluorophosphate (LiPF ６ ) was dissolved to a concentration of 1 M to prepare electrolyte solution 3. (Electrolyte solution 4) Ethylene carbonate (EC) and propylene carbonate (PC) were mixed in a volume ratio of EC:PC = 1:1 to prepare a solution containing lithium hexafluorophosphate (LiPF ６ ) was dissolved to a concentration of 1 M to prepare electrolyte solution 4. (Electrolyte solution 5) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC = 1:1, and sodium hexafluorophosphate (NaPF ６ ) was dissolved to a concentration of 1M to prepare electrolyte solution 5.

[0128] (Preparation of negative electrode active material) The following negative electrode active materials were prepared. Graphite 1: artificial graphite (FSN-1, manufactured by Shanshan China Co., Ltd., volume average particle diameter (D50): 15.3 μm) Graphite 2: spherical graphite (CGR 12R, manufactured by Nippon Graphite Industries Co., Ltd., volume average particle diameter: 10.6 μm) HC: hard carbon (non-graphitizable carbon) powder (manufactured by Kureha Battery Materials Japan Co., Ltd., Carbotron (registered trademark) PS (F), volume average particle diameter (D50): 20.0 μm)

[0129] (Calculation of HSP Value of Negative Electrode Active Material: Graphite 1) The dispersibility of graphite 1 in various solvents was evaluated by the following method. 20 mL of a solvent with a known solubility parameter and 0.04 g of graphite 1 were placed in a Maruemu Co., Ltd. No. 7 screw tube, and a stirrer was added. The mixture was stirred at 400 rpm for 30 minutes to prepare a suspension. The suspension was then left to stand in a constant temperature bath at 25°C for 12 hours to prepare a dispersion for measurement. The solvents with known solubility parameters were toluene, N-methylpyrrolidone (NMP), diethyl carbonate, dimethylformamide, 1,4-dioxane, hexane, cyclohexane, methanol, ethanol, acetone, acetonitrile, and methyl ethyl ketone (MEK). The solubility parameters of these solvents were determined by reference to the HSPiP database. Also, 20 mL of each solvent was placed in a Maruemu Co., Ltd. No. 7 screw tube, and similarly left to stand in a constant temperature bath at 25°C for 12 hours to prepare a reference solvent.

[0130] Baseline measurements were performed using an ultraviolet-visible-near-infrared spectrophotometer (UV-3600i Plus, Shimadzu Corporation) in a reference solvent. The measurement dispersion corresponding to the reference solvent was then stirred in a screw tube for more than 1 minute, and while stirring in a fully dispersed state, 1000 μL each was transferred to a quartz cell containing a stir bar four times with a micropipette, and used as a measurement cell. The measurement cell was set in a holder with a stirrer, stirred for 30 seconds, and the measurement of the absorption spectrum was started at the same time as stopping the stirring, and the absorbance value was recorded at 10-second intervals for 20 minutes (measurement wavelength: 632 nm). The dispersion index (DISP) was calculated as "absorbance after 20 minutes (A20) / absorbance at the start of measurement (A0)". The obtained dispersion index was used to evaluate the dispersibility in each solvent based on the following evaluation criteria.

[0131] (Evaluation criteria) 1: DISP = 0.30 or more 2: DISP = 0.20 or more and less than 0.30 3: DISP = 0.15 or more and less than 0.20 4: DISP = 0.10 or more and less than 0.15 5: DISP = less than 0.10 The HSP value of graphite 1 was calculated from the evaluation results of the dispersibility of graphite 1 in a solvent by inputting the results into HSPiP. The evaluation results of dispersibility used to calculate the HSP value of graphite 1 are shown in Table 1.

[0132]

[0133] (Calculation of HSP value of negative electrode active material: graphite 2) The HSP value of graphite 2 was also calculated in the same manner as for graphite 1. Of the solvents with known solubility parameters used to calculate the HSP value of graphite 1, hexane was not used, and other solvents were used instead. The other procedures were the same as for graphite 1. The evaluation results of dispersibility used to calculate the HSP value of graphite 2 are shown in Table 2.

[0134]

[0135] (Calculation of HSP Value of Negative Electrode Active Material: HC) The HSP value of HC was calculated in the same manner as for graphite 1. Table 3 shows the evaluation results of dispersibility used to calculate the HSP value of HC.

[0136]

[0137] The solubility parameters of graphite 1, graphite 2 and HC calculated based on the results shown in Tables 1, 2 and 3 are shown in Table 4.

[0138]

[0139] (Reference Examples 1 to 19, HSP distance between compound (A) and active material or electrolyte) The HSP distances between compounds (A1) to (A19) and graphite 1, graphite 2, and HC as active materials, and the HSP distances between compounds (A1) to (A19) and electrolytes 1 to 5 are summarized in Table 5. The unit of HSP distance in each table shown below is [MPa ０．５ ].

[0140] The results of the electrolyte penetration test when the compounds (A1) to (A19) were combined with graphite 1 as the active material and electrolyte solution 1 as the electrolyte, as well as the results of the cohesive failure test when the compounds (A1) to (A19) were combined with graphite 1 as the active material, are shown in Table 5. The electrolyte penetration test and the cohesive failure test were carried out in the same manner as in the procedures of Example 1 below, and measurements were taken on a composition in which the content of compound (A) in the electrode composition was 1.0% and to which compound (B) and compound (C) were not added.

[0141]

[0142] Among the compounds (A1) to (A19), the compounds (A1) to (A8) satisfy the requirement (5) described in this specification. Compound (A8) has an HSP distance (Ra_Act) of 12.0 MPa for all of graphite 1, graphite 2, and HC. ０．５ and does not satisfy requirement (3) in the present specification in relation to graphite 1, graphite 2, and HC. Therefore, in relation to graphite 1, graphite 2, and HC, compounds (A1) to (A7) are compounds that may be used as compound (A) in the electrode composition of the present invention.

[0143] In relation to graphite 1, the compounds (A1) to (A7) all have an HSP distance (Ra_Act) of 12.0 MPa. ０．５ Among the compounds (A1) to (A7), the compounds (A1) to (A3) and the compounds (A5) to (A7) have an HSP distance (Ra_Act) of 12.0 MPa in relation to graphite 2. ０．５ Among the compounds (A1) to (A7), the compounds (A1) to (A3) and the compounds (A6) to (A7) all have an HSP distance (Ra_Act) of 12.0 MPa in relation to HC. ０．５ The details are as follows.

[0144] In the case of the compounds (A1) to (A7), the HSP distance (Ra_Elec) was 14.0 MPa in relation to the electrolytes 1 to 3 and 5. ０．５ Among the compounds (A1) to (A7), the compounds (A4) and (A5) have a (Ra_Elec) of 14.0 MPa in relation to the electrolyte 4. ０．５ The details are as follows.

[0145] The results of the electrolyte penetration test showed that the compounds (A1) to (A7) and (A12) to (A19) had short electrolyte penetration times and good electrolyte permeability. These compounds (A1) to (A7) and (A12) to (A19) had an HSP distance (Ra_Act) of 12.0 MPa relative to the active material in relation to graphite 1. ０．５ The HSP distance (Ra_Elec) between the electrolyte and the electrolyte 1 is 14.0 MPa. ０．５ The compound is as follows:

[0146] The results of the cohesive fracture test showed that compounds (A1) to (A7) had high cohesive fracture strength. These compounds (A1) to (A7) had an HSP distance (Ra_Act) of 12.0 MPa relative to the active material in relation to graphite 1. ０．５ and is a compound having a polyoxyethylene group with a repeating number of 3 or more.

[0147] (Examples 1 to 18, Comparative Examples 1 to 14) (Preparation of Additives) Additives were prepared so that the respective contents of compound (A1), compound (B1), and compound (C1) in the electrode composition, based on the solid content weight of the electrode composition, were the proportions shown in Table 6 or Table 7. For example, when the respective contents of compound (A1), compound (B1), and compound (C1) in the electrode composition were to be 1.0%, 20 ppm, and 6 ppm, compound (A1) was mixed with compound (B1) and compound (C1) so that the weight ratios were 2000 ppm and 600 ppm, respectively. In this case, the content of compound (A1) in the electrode composition was less than 1.0%, strictly speaking, but is listed as 1.0% in the tables of Examples 1 to 42.

[0148] (Preparation of Negative Electrode with Additive Added) 2.0 parts by weight of AB (acetylene black: “Denka Black Li100”, manufactured by Denka Co., Ltd., average particle size of primary particles: 35 nm) as a conductive additive, 3.0 parts by weight of CMC (carboxymethyl cellulose) as a binder resin, and 40.0 parts by weight of ion-exchanged water were stirred at 2000 rpm for 5 minutes using a planetary stirring type mixer / kneader (Awatori Rentaro, manufactured by Thinky Corporation).

[0149] Next, 3.0 parts by weight of SBR (styrene butadiene rubber) as a binder resin was added, and the mixture was stirred for 5 minutes at 2000 rpm using a mixer. To the resulting dispersion, 91.0 parts by weight of graphite 1 as a negative electrode active material and additives prepared in advance so that the contents of compound (A1), compound (B1), and compound (C1) were as shown in Table 5 or Table 6 were added, and 60.0 parts by weight of ion-exchanged water was further added, and the mixture was stirred for 5 minutes at 2000 rpm using a mixer to prepare an electrode composition.

[0150] The obtained electrode composition was applied to one side of a current collector (copper foil) using an applicator with a clearance set to 150 μm in the atmosphere, pre-dried overnight in a draft, and then further dried at 110 ° C for 2 hours to obtain an electrode sheet. Sixteen pieces of 16 mm diameter were punched out near the center of the electrode sheet. This operation was repeated multiple times, and the obtained electrode was pressed twice with a press at 1.5 MPa for 3 seconds to prepare an evaluation electrode (negative electrode). The electrode sheet was cut with a cutter to a length of 8.0 cm and a width of 2.5 cm, and pressed twice with a press at 1.5 MPa for 3 seconds to prepare an electrode (negative electrode) for cohesive failure testing.

[0151] <Calculation of electrode density> The weight and thickness of the current collector and the evaluation electrode were measured after being pressed twice for 3 seconds at 1.5 MPa using a press machine, and the electrode density (g / cm) was calculated using the following formula. ３ ) = (evaluation electrode weight (g) - current collector weight (μg) × 10 －３ ) / (0.8 ２ × 3.14 × ((evaluation electrode thickness (μm) − current collector thickness (μm)) × 10 －４ ))

[0152] <Electrolyte penetration test> The electrode density (g / cm ３ ) maximum and minimum difference is 0.03 (g / cm ３ Three electrodes were selected so that the electrode density (g / cm) of the evaluation electrode was within the range of 0.01 to 0.01. ３A stainless steel M3 flat washer (manufactured by ESCO) was placed at the center of each electrode, and 20 μL of electrolyte (electrolyte 1) was dropped into the hole in the washer. The time until the droplet in the washer completely disappeared from the electrode surface was recorded in 1-second units, and the arithmetic mean value was taken as the electrolyte penetration time (penetration rate: min).

[0153] <Cohesive Failure Test> Double-sided tape (Nichiban Nicetack: Model No. NW-K15) was applied to the electrode composition surface of the electrode (negative electrode) for cohesive failure testing, and the electrode composition surface was bonded to a SUS plate so that it faced the SUS plate to form a test specimen. The metal foil at one end of the test specimen was peeled off from the SUS plate, and the electrode composition was peeled off from the current collector by gripping the SUS plate side with the chuck of the lower test jig of a benchtop precision universal testing machine (Autograph AGS-X, Shimadzu Corporation) and the metal foil with the chuck of the upper jig. A 20 N test jig was used, and the tensile speed was 100 mm / min. After the test, the SUS plate was removed, and double-sided tape (Nichiban Nice Tack: model number NW-K15) was attached to the surface of the electrode composition attached to the double-sided tape so that the foot extended 3 cm from the SUS plate. The SUS plate was held in the chuck of the lower test jig and the foot of the double-sided tape in the chuck of the upper test jig, and a cohesive failure test was performed. A 20 N test jig was used, and the tensile speed was 100 mm / min. The obtained measurement results were read in accordance with JIS K 6854-2:1999 to determine the average peel force (N). The average peel force was divided by the width (0.025 m) of the test piece and recorded as the cohesive failure force (N / m). If the cohesive failure force value is small, the electrode composition becomes brittle and easily peels off from the electrode surface.

[0154] <Capacity retention rate after severe test> Preparation of negative electrode half-cell for capacity retention rate severe test ３ ) maximum and minimum difference is 0.03 (g / cm ３ Three electrodes were selected so that the electrode density (g / cm) of the evaluation electrode was within the range of 0.01 to 0.01. ３The negative electrode, a separator [product name "#3501" manufactured by Celgard Inc.], and a lithium foil were stacked in this order from the negative electrode side, an electrolyte solution (electrolyte solution 1) was injected, and then the resultant was vacuum laminated to prevent oxygen from entering, thereby preparing a negative electrode half cell for a capacity retention rate severe test.

[0155] Negative Electrode Half-Cell Charge / Discharge Test At 25°C, a charge / discharge measuring device "HJ-SD8" [manufactured by Hokuto Denko Corporation] was used to evaluate the capacity retention rate of the negative electrode half-cell for the severe test by the following method. The cell was charged to 0 V at a current of 0.05 C using a constant current charging method (also referred to as CC mode), and after a 10-minute pause, it was discharged to 1.5 V at a current of 0.05 C. The discharged capacity at this time was defined as [1-cycle discharge capacity (mAh)]. Charge / discharge was performed again under the same conditions, and the discharged capacity at this time was defined as [2-cycle discharge capacity (mAh)]. Next, the cell was charged to 0 V at a current of 0.1 C, and after a 10-minute pause, it was discharged to 1.5 V at a current of 0.1 C. The discharged capacity at this time was defined as [3-cycle discharge capacity (mAh)]. Furthermore, the cells were charged to 0 V at a current of 0.5 C, and after a 10-minute pause, discharged to 1.5 V at a current of 0.1 C. The discharged capacity at this time was recorded as [4-cycle discharge capacity (mAh)]. Finally, the cells were charged to 0 V at a current of 1.0 C, and after a 10-minute pause, discharged to 1.5 V at a current of 0.1 C. The discharged capacity at this time was recorded as [5-cycle discharge capacity (mAh)]. The capacity retention rate after the severe test for each of the three electrodes was calculated using the following formula, and the arithmetic average was recorded as the capacity retention rate (%) of the evaluation electrode after the severe test. Capacity retention rate after severe test (%) = [5-cycle discharge capacity (mAh)] / [2-cycle discharge capacity (mAh)]. In addition, cells that showed swelling after the charge-discharge test were recorded as having generated gas. In the table, cells that showed swelling were marked with an X, and cells that showed no swelling were marked with an O.

[0156] The above evaluation results are summarized in Tables 6 and 7.

[0157]

[0158]

[0159] The evaluation results shown in Tables 6 and 7 indicate that when the additive contained in the electrode composition contained compound (A) and further contained compound (B) and / or compound (C) in an amount that satisfied all of the relational expressions (i) to (iv) shown in requirement (7) of the present specification, the penetration rate of the electrolyte solution was fast and the cohesive fracture strength was high. Furthermore, the results of the severe test indicated that, compared to when the additive contained only compound (A), when compound (B) and / or compound (C) were contained in an amount that satisfied all of the relational expressions (i) to (iv) shown in the present specification, an improved capacity retention rate was obtained.

[0160] The greater the content of compound (B) and compound (C) in the electrode composition, the greater the effect of improving the capacity retention rate. However, it was found that when the total content of compound (B) and compound (C) in the electrode composition exceeds 50 ppm, the cohesive fracture strength of the electrode decreases (the peel strength of the electrode decreases) (see Comparative Examples 5, 9, and 10). Furthermore, when the content of compound (C) exceeds 11 ppm, swelling occurred in the cell after the severe test, and the capacity retention rate also decreased (see Comparative Examples 11 and 12). Furthermore, when compound (B) and compound (C) were added to the electrolyte, the effect of improving the capacity retention rate was not obtained, and it was found that adding compound (B) and compound (C) to the electrode composition was effective (see Comparative Examples 13 and 14).

[0161] (Examples 19 to 36, Comparative Examples 15 to 28) Compound (A7), compound (B7), and compound (C7) were used as the compounds used in (Preparation of additives) described in the section of Example 1, etc., to prepare additives so that the content based on the solid content weight of the electrode composition was the ratio shown in Table 8 or Table 9.

[0162] A negative electrode containing the additive was prepared and evaluated for each evaluation item in the same manner as in Example 1. The evaluation results are summarized in Tables 8 and 9.

[0163]

[0164]

[0165] From the evaluation results shown in Tables 8 and 9, it was found that even when the combination of compound (A), compound (B), and compound (C) was compound (A7), compound (B7), and compound (C7), effects similar to the results shown in Tables 6 and 7 could be obtained.

[0166] (Examples 37 to 41, Comparative Examples 29 to 38) Compounds (A2) to (A6), compound (B1), and compound (C1) were used as the compounds used in (Preparation of additives) described in the section of Example 1, etc., to prepare additives so that the content based on the solid content weight of the electrode composition was the ratio shown in Table 10 or Table 11.

[0167] A negative electrode containing the additive was prepared and evaluated for each evaluation item in the same manner as in Example 1. The above evaluation results are summarized in Tables 10 and 11.

[0168]

[0169]

[0170] From the evaluation results shown in Tables 10 and 11, it was found that even when compound (A) was any of compounds (A2) to (A6), effects similar to those shown in Tables 6 and 7 could be obtained.

[0171] (Examples 42 to 55) In Example 1 (production of negative electrode containing additive), the electrode composition was applied to one side of a current collector, and the drying temperature after pre-drying in a draft was changed from 110°C to 130°C or 150°C to produce electrodes (evaluation electrode (negative electrode) and cohesive failure test electrode (negative electrode)). These electrodes were used to evaluate each evaluation item. The above evaluation results are summarized in Table 12.

[0172]

[0173] Table 12 shows the evaluation results when the electrode drying temperature was changed. It can be seen that when the drying temperature was high, compound (B) and compound (C) volatilized, and the effect of containing compound (B) and / or compound (C) in improving the capacity retention rate decreased.

[0174] (Examples 56 to 70, Comparative Examples 39 to 61) (Preparation of Additives) As the compounds used in (Preparation of Additives) explained in the section of Example 1, etc., Compound (A), Compound (B), and Compound (C) of the types shown in Table 13 or 14 were used to prepare additives so that the respective contents based on the solid content weight of the electrode composition were the proportions shown in Table 13 or Tables 14-1 and 14-2.

[0175] Negative electrodes containing additives were prepared and evaluated for each evaluation item in the same manner as in Example 1. Electrolyte solution 2 was used as the electrolyte in preparing negative electrode half-cells for the electrolyte penetration test and the capacity retention rate severe test. The above evaluation results are summarized in Table 13, Tables 14-1 and 14-2.

[0176]

[0177]

[0178]

[0179] From the evaluation results shown in Table 13 and Tables 14-1 and 14-2, it can be seen that even when electrolyte solution 2 is used, the permeability is improved when the additive contained in the electrode composition contains compound (A) and further contains compound (B) and / or compound (C) in amounts that satisfy all of the relational expressions (i) to (iv) shown in requirement (7) of this specification. It can also be seen that the permeability effect increases with an increase in the amount of compound (A), but there is no significant change even when compound (A) is added at 1.0% or more (see Examples 62 to 67). When the electrode composition does not contain compound (A) but contains compounds (B) and (C), the cohesive fracture strength tends to decrease, but when compound (A) is further contained, the cohesive fracture strength tends to improve (e.g., Comparative Examples 39, 40, 41 and Example 56). It was found that similar effects to those shown in Table 6-11 can be obtained even when the combination of graphite and electrolyte solution is changed. Comparative Examples 40 and 41 are examples in which the electrode composition has the same composition but different electrode densities. When the electrode densities differ to a certain extent between these two examples (the difference is less than 0.05 g / cm ３ ) It can be seen that the evaluation results of the permeability are the same. Comparative Examples 63, 64, 87, and 88 described below are also shown as examples in which the electrode composition has the same composition but different electrode densities.

[0180] (Examples 71 to 84, Comparative Examples 62 to 85) (Preparation of Additives) As the compounds used in (Preparation of Additives) explained in the section of Example 1, etc., Compound (A), Compound (B), and Compound (C) of the types shown in Table 15 or 16 were used to prepare additives so that the respective contents based on the solid content weight of the electrode composition were the proportions shown in Table 15 or Tables 16-1 and 16-2.

[0181] The negative electrode active material used in the example (preparation of a negative electrode with an additive added) described in Example 1 was changed to graphite 2, and a negative electrode with an additive added was prepared and evaluated for each evaluation item. Electrolyte 1 was used as the electrolyte in preparing a negative electrode half-cell for the electrolyte penetration test and the capacity retention rate severe test. The above evaluation results are summarized in Table 15, Tables 16-1 and 16-2.

[0182]

[0183]

[0184]

[0185] From the evaluation results shown in Tables 15, 16-1 and 16-2, it was found that effects similar to those shown in Tables 5 and 6 could be obtained even when the negative electrode active material was changed.

[0186] (Examples 85 to 97, Comparative Examples 86 to 110) (Preparation of Additives) Additives were prepared using the types of compound (A1), compound (B1), and compound (C1) shown in Table 17 or 18, so that the content based on the weight of the solid content of the electrode composition was the ratio shown in Table 17, or Tables 18-1 and 18-2.

[0187] The negative electrode active material used in the preparation of a negative electrode with an additive added, as described in Example 1, etc., was changed to HC, and a negative electrode with an additive added was prepared and evaluated for each evaluation item. Electrolyte 5 was used as the electrolyte in the preparation of a negative electrode half-cell for the electrolyte penetration test and the capacity retention rate severe test. The lithium foil in the preparation of a negative electrode half-cell for the capacity retention rate severe test was changed to a sodium foil. These evaluations were performed on a sodium-ion battery. The above evaluation results are summarized in Table 17, Tables 18-1, and 18-2.

[0188]

[0189]

[0190]

[0191] From the evaluation results shown in Table 17 and Tables 18-1 and 18-2, it was found that the same effects as the results for the lithium ion batteries shown in Tables 6-11 could be obtained with sodium ion batteries.

Claims

1. An electrode composition for a secondary battery electrode layer containing an electrolytic solution, which satisfies all of the following (1) to (7): (1) Contains an active material and an additive, but does not contain a binder resin; (2) The additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) The HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont 2. An electrode composition for a secondary battery electrode layer containing an electrolytic solution, the electrode composition satisfying all of the following (1) to (7): (1) containing an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont 3. The electrode composition according to claim 1 or 2, wherein the compound (A) is one selected from the group consisting of an ethylene oxide adduct of an alkyl alcohol, an ethylene oxide adduct of (di)ethylene glycol, and a polyethylene glycol (di)alkyl ether.

4. The electrode composition according to claim 1 or 2, wherein the compound (B) is a diethylene glycol (di)alkyl ether.

5. The electrode composition according to claim 1 or 2, wherein the compound (C) is an ethylene glycol (di)alkyl ether.

6. The HSP distance (Ra_Act) between the compound (A) and the active material is 4.0 MPa. ０．５ 3. The electrode composition according to claim 1 or 2, wherein the above-mentioned 7. The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 12.0 MPa. ０．５ 3. The electrode composition according to claim 1, wherein:

8. The electrode composition according to claim 1 or 2, wherein the active material is artificial graphite or natural graphite.

9. The electrode composition according to claim 1 or 2, wherein the solvent of the electrolyte is a mixed solvent of ethylene carbonate and diethyl carbonate, a mixed solvent of ethylene carbonate, ethyl methyl carbonate and diethyl carbonate, or a mixed solvent of ethylene carbonate and propylene carbonate.

10. A secondary battery electrode obtained by compression molding the electrode composition according to claim 1 or 2.

11. A secondary battery comprising the electrode for a secondary battery according to claim 10.

12. A secondary battery comprising a current collector layer, a secondary battery electrode layer, and a separator layer, which satisfies all of the following (1) to (7): (1) the secondary battery electrode layer comprises an electrode composition containing an active material and an additive, and not containing a binder resin, and an electrolyte; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont 13. A secondary battery comprising a current collector layer, a secondary battery electrode layer, and a separator layer, which satisfies all of the following (1) to (7): (1) the secondary battery electrode layer comprises an electrode composition containing an active material, a binder resin, and an additive, and an electrolyte; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont 14. A method for manufacturing a secondary battery, comprising the steps of: permeating an electrolyte solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer; and obtaining a secondary battery electrode layer in which the electrolyte solution is contained in the electrode composition layer, wherein the method satisfies all of the following (1) to (7): (1) the electrode composition layer contains an active material and an additive, but does not contain a binder resin; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont 15. A method for manufacturing a secondary battery, comprising a step of permeating an electrolyte solution into a battery unit including a current collector layer, an electrode composition layer, and a separator layer to obtain a secondary battery electrode layer in which the electrolyte solution is contained in the electrode composition layer, wherein the method satisfies all of the following (1) to (7): (1) the electrode composition layer contains an active material, a binder resin, and an additive; (2) the additive contains a compound (A), and the content of the compound (A) is 0.01 to 2.0 wt % based on the solid content weight of the electrode composition; (3) the HSP distance (Ra_Act) between the compound (A) and the active material is 12.0 MPa. ０．５ (4) The HSP distance (Ra_Elec) between the compound (A) and the electrolyte is 14.0 MPa or less; ０．５ (5) the compound (A) has a polyoxyethylene group with a repeating number of 3 or more; (6) the additive contains a compound (B) having one diethylene glycol group and / or a compound (C) having one ethylene glycol group; (7) the content of the compound (B) (B_cont, unit: ppm) and the content of the compound (C) (C_cont, unit: ppm) based on the solid content weight of the electrode composition satisfy all of the following relational expressions (i) to (iv): (i) 0≦B_cont≦50 (ii) 0≦C_cont≦10 (iii) 0<B_cont+C_cont≦50 (iv) When 0≦C_cont<0.5, 20≦B_cont When 0.5≦C_cont<1.5, 15≦B_cont When 1.5≦C_cont<2.5, 7≦B_cont When 2.5≦C_cont<4.5, 5≦B_cont When 4.5≦C_cont, 0≦B_cont 16. A method for producing a secondary battery according to claim 14 or 15, comprising the steps of applying an electrode composition to the current collector layer to form an electrode composition layer on the current collector layer, and drying the electrode composition layer at a drying temperature of 150°C or less to obtain an electrode sheet in which the current collector layer and the electrode composition layer are combined.

Images