Abstract: An electrode of a secondary battery includes an electrode active material layer containing active material particles. A concave part is formed on the surface of the electrode active material layer. When the electrode active material layer is uniformly divided into three layers, an upper layer, an intermediate layer and a lower layer, in the thickness direction from the surface of the concave part to the electrode current collector, and the electrode densities (g/cm3) of the upper layer, the intermediate layer, and the lower layer are d1, d2, and d3, respectively, they have a relationship of 0.8<(d1/d3)<1.1. The porosity of the electrode active material layer is 10% or more and 50% or less. The area ratio of the concave part is 2% or more and 40% or less. The volume ratio of the concave part is 5% or more and 14% or less.

Abstract: Provided is a method for producing an electrode having an electrode active material layer in which the form of both edges is advantageously adjusted. A method for producing an electrode disclosed here is a method for producing an electrode which includes a long sheet-shaped electrode current collector of a positive electrode or a negative electrode; and a long sheet-shaped electrode active material layer formed on the electrode current collector. The method for producing an electrode includes the following steps: an electrode material preparation step for preparing an electrode material; a film formation step for forming a coating film in the sheet longitudinal direction on the electrode current collector using the electrode material; and a roller forming step for adjusting the form of both edge parts in the sheet longitudinal direction of the coating film using a forming roller.

Abstract: The method for producing a secondary battery electrode disclosed here includes steps of: preparing a moisture powder formed by aggregated particles that contain electrode active material particles, a binder resin, and solvent, wherein a solid phase, liquid phase, and gas phase in at least 50 number % or more of the aggregated particles in the moisture powder form a pendular or funicular state; forming a coating film composed of the moisture powder, on an electrode current collector, while the gas phase remains present; carrying out depression/elevation transfer into a surface part of the coating film; forming an electrode active material layer by drying the coating film; and pressing the electrode active material layer. The electrode active material particles are aspherical particles in which a ratio of a short side to a long side in a cross sectional view is less than 0.95.

Abstract: A method of producing an electrode disclosed here includes a step in which a moisture powder formed of agglomerated particles; a step in which a coating film composed of the moisture powder is formed on an electrode current collector by using the moisture powder, with a gas phase of the coating film being remained, so that the average film thickness of the coating film is 50 ?m or more; a step in which the coating film on the electrode current collector is transported, concavo-convex transfer is performed by using a roll mold, and thus a plurality of grooves extending in a direction orthogonal to a transport direction are formed on a surface part of the coating film so that a depth of the groove satisfies (9/10×t1)>t2, and a step in which the coating film formed on the electrode current collector is dried to form an electrode active material layer.

Abstract: An electrode disclosed here includes a surface part of an electrode active material layer has a plurality of first grooves extending in a width direction of the electrode current collector and at least one second groove extending in a longitudinal direction of an electrode current collector. The first groove is formed to be continuous from one end to another end. Here, a region in which the first groove and the second groove are formed is uniformly divided into three layers, which are an upper layer, an intermediate layer and a lower layer, in a thickness direction from the surface of the electrode active material layer to the electrode current collector, and when electrode densities (g/cm3) of the upper layer, the intermediate layer and the lower layer of the groove are d1, d2, and d3, respectively, a relationship of 0.8<(d1/d3)<1.1 is satisfied.

Abstract: A method of producing an electrode disclosed here includes a step in which a moisture powder formed of agglomerated particles; a step in which by using the moisture powder, a coating film composed of the moisture powder is formed on an electrode current collector, with a gas phase of the coating film being remained so that the average film thickness of the coating film is 50 ?m or more; a step in which the coating film on the current collector is transported, concavo-convex transfer is performed using a roll mold, and thus at least one groove extending in the transport direction is formed in a center of a surface part of the coating film, with the groove being formed to have a depth satisfying ( 9/10×t1)>t2; and a step in which the coating film formed on the current collector is dried to form an electrode active material layer.

Abstract: According to the present disclosure, an electrode having an electrode mixture layer with a desired film thickness can be stably produced. An electrode production apparatus disclosed herein includes: a first roll; a second roll; third roll; a rolling gap for rolling an electrode material to form a mixture coated film, formed between the first roll and the second roll; and a compression bonding gap for compressedly bonding the mixture coated film and an electrode current collector, formed between the second roll and the third roll. The electrode production apparatus further includes a spring-like mechanism configured to bias the third roll toward the second roll. The compression bonding gap fluctuates in response to the fluctuation of the reaction force from the mixture coated film. As a result, the film thickness variation of the electrode mixture layer after the production can be reduced.

Abstract: According to the present disclosure, an electrode having an electrode mixture layer with a desired film thickness can be stably produced. A producing method disclosed herein includes detecting the surface position of a mixture coated film by a first sensor; detecting the surface position of a second roll by a second sensor; detecting the film thickness of the mixture coated film based on detection results of the first sensor and the second sensor; and adjusting a relatively rotation speed of a third roll based on the film thickness. And, the detected positions of the first sensor and the second sensor in a circumferential direction of the second roll are substantially identical. Due to this method, the change in the film thickness of the electrode mixed layer of produced electrode can be suppressed.

Abstract: Provided by the present disclosure is an electrode material (mixture) which exhibits good spreadability and in which the surface area of an electrode active material layer at the stage of a coating film prior to drying can be easily increased by press molding. A moisture powder for forming an electrode active material layer on an electrode current collector of a positive electrode or negative electrode disclosed here is constituted from aggregated particles that contain a plurality of electrode active material particles, a binder resin and a solvent, wherein at least 50% by number or more of the aggregated particles that constitute the moisture powder have the following properties: (1) a solid phase, a liquid phase and a gas phase form a pendular state or a funicular state; and (2) a layer of the solvent is not observed at the outer surface of an aggregated particle in electron microscope observations.

Abstract: A method for producing a coated active material includes dropletizing a slurry to obtain slurry droplets wherein the slurry contains an active material and a coating liquid, gas-flow drying the slurry droplets in a heating gas to obtain a precursor, and firing the precursor.

Abstract: A method for producing a positive electrode sheet is provided with a positive current collecting foil made of aluminum and a battery positive active material layer containing positive active material particles made of LiNiMn based spinel and applied and dried on the current collecting foil. The positive active material layer includes a first binder made of polyacrylic acid with a molecular weight of 50,000 or less and a second binder made of polyacrylic acid with a molecular weight of 300,000 or more. The first positive electrode paste forming the positive active material layer satisfies expressions (1) to (3): ??1.7??(1) ??0.9??(2) ?+??3.0??(3) where ? is an additive amount of the first binder in pts. wt. and ? is an additive amount of the second binder in pts. wt. when other solid content is 100 pts. wt.

Abstract: Provided is a method of manufacturing a lithium ion secondary battery. The method includes a step of initially charging the battery. The step includes: a first step of charging the battery such that a voltage Vt of the battery is increased to a first voltage Vh which is in a lower decomposition range Ad; a second step of holding the voltage Vt of the battery at the first voltage Vh; and a third step of charging the battery to a second voltage Ve, which is higher than the first voltage Vh, after the second step.

Abstract: In a positive-electrode active material layer of a positive-electrode plate for a non-aqueous electrolyte secondary battery, a dispersion index value C determined from a small-size-particle ratio A and a coefficient B of variation and expressed by an expression, C=B/A3, is 0.8 or less. The small-size-particle ratio A is a ratio of the number of small-size-particle-containing spots where a detected intensity of phosphorus is equal to or lower than a detected density of trilithium phosphate having a particle size of 1 ?m or less, to the number of phosphorus-containing spots among the analyzed spots. The coefficient B of variation is a ratio of a standard deviation of segmented-region accumulated values to an arithmetic mean of the segmented-region accumulated values each of which is the sum of detected intensities in the phosphorus-containing spots in a corresponding one of the segmented regions obtained through segmentation of the analyzed region.

Abstract: A lithium ion secondary battery includes: a positive electrode sheet that includes a positive electrode active material layer containing a positive electrode active material particle; a negative electrode sheet; and a nonaqueous electrolytic solution that contains a compound containing fluorine, wherein a surface of the positive electrode active material particle includes a film containing fluorine and phosphorus, and a ratio Cf/Cp satisfies 1.89?Cf/Cp?2.61 where Cf represents the number of fluorine atoms in the film, and Cp represents the number of phosphorus atoms in the film.

Abstract: In a positive electrode mixture paste manufacturing step, a positive electrode mixture paste is manufactured by further mixing an acid compound, in addition to a positive-electrode active material, a conductive material, a binder, lithium phosphate, and a solvent.

Abstract: A method of manufacturing a nonaqueous electrolyte secondary battery includes: manufacturing a positive electrode sheet by forming a positive electrode active material layer, which includes trilithium phosphate, on a positive electrode current collector foil; accommodating the positive electrode sheet, a negative electrode sheet, and an electrolytic solution in a battery case; and charging a battery after the accommodation. During the manufacturing of the positive electrode sheet, a positive electrode active material is a composite oxide including at least lithium and manganese. During the manufacturing of the positive electrode sheet, a conductive additive is obtained by attaching at least one of manganese or manganese oxide to a surface of a carbon material.

Abstract: A method of manufacturing a nonaqueous electrolyte secondary battery includes: a first step of preparing a positive electrode mixture paste; and a second step of preparing a positive electrode. In the first step, at least one binder including an acidic binder in an amount set such that a pH value of an aqueous solution obtained by dissolving the set amount of acidic binder in the same amount of water as that of the solvent is within a range of 1.7 to 5.5 is used.

Abstract: A method of manufacturing a nonaqueous electrolyte secondary battery includes a positive electrode paste preparation step, a positive electrode sheet preparation step, a construction step, and an initial charging step. In the positive electrode paste preparation step, a positive electrode paste is prepared by dispersing a positive electrode active material, a binder, and a metal phosphate in a solvent. The metal phosphate includes a first metal phosphate and a second metal phosphate having an average particle size which is more than that of the particles of the first metal phosphate by 1.3 ?m or more.

Abstract: A manufacturing method of a nonaqueous electrolyte secondary battery includes: a lithium phosphate dispersion manufacturing step of manufacturing a lithium phosphate dispersion by dispersing lithium phosphate in a solvent without adding a positive-electrode active material; a positive electrode mixture paste manufacturing step of manufacturing a positive electrode mixture paste by mixing the lithium phosphate dispersion with a positive electrode material including the positive-electrode active material; and a step of manufacturing a positive electrode including a positive electrode mixture layer on a surface of a current collector member by applying the positive electrode mixture paste on the surface of the current collector member and drying the positive electrode mixture paste.

Abstract: In a method of manufacturing a lithium ion secondary battery, first, lithium nickel manganese oxide which is a positive electrode active material is exposed to fluorine-based gas to form a coating film containing amorphous lithium fluoride on a surface of the positive electrode active material. Next, a phosphate compound is added to the positive electrode active material on which the coating film containing the lithium fluoride is formed. After a lithium ion secondary battery which includes a positive electrode including the positive electrode active material is formed, the lithium ion secondary battery is charged to form a coating film containing amorphous lithium phosphate on the surface of the positive electrode active material.