Abstract:
The present invention provides a non-aqueous electrolyte secondary battery that can suppress a drop in a flash point of an electrolyte solution even if the non-aqueous electrolyte secondary battery is used for a long time. The non-aqueous electrolyte secondary battery includes: an electrode body having a structure in which a positive electrode including a positive-electrode active material and a negative electrode including a negative-electrode active material are stacked with a separator interposed therebetween; a non-aqueous electrolyte solution containing a flame retardant; and an outer casing accommodating the electrode body and the non-aqueous electrolyte solution. The non-aqueous electrolyte solution in the electrode body has a flame retardant concentration lower than a flame retardant concentration in the non-aqueous electrolyte solution between the electrode body and the outer casing.
Abstract:
The present invention provides a positive electrode for non-aqueous electrolyte secondary battery, having a novel overcharge protective function. The positive electrode for non-aqueous electrolyte secondary battery according to the present invention includes a positive electrode active material layer including a plurality of positive electrode active material particles, wherein the positive electrode active material layer comprises: a carbonaceous coating film formed on a surface of each of the positive electrode active material particles; and 0% by weight or more and 20% by weight or less of a conductive auxiliary agent disposed between the plurality of positive electrode active material particles, and at least one of the carbonaceous coating film and the conductive auxiliary agent is graphitizable carbon.
Abstract:
A positive electrode active material for a non-aqueous electrolyte secondary battery according to the present invention is characterized by including positive electrode active material particles, and a carbonaceous coating film formed on the surface of the positive electrode active material particle and including a plurality of carbon hexagonal network planes, wherein the carbonaceous coating film is formed so that a Raman spectrum, in which a ratio ID/IG between a peak intensity ID of the D band and a peak intensity IG of the G band is 0.9 or lower and the full width at half maximum of the peak of the G band is 80 cm−1 or smaller, is measured.
Abstract:
A method of the present invention for manufacturing a lithium-ion cell comprises the step of impregnating a porous positive-electrode active material layer or a porous negative-electrode active material layer with an ionic liquid electrolyte. The ionic liquid electrolyte includes: an ionic liquid comprising an anion and a cation; and a lithium salt dissolved in the ionic liquid. The anion is bis(fluorosulfonyl)imide ion. The lithium salt is lithium bis(fluorosulfonyl)imide or lithium bis(trifluoromethansulfonyl)imide. The ionic liquid electrolyte contains the lithium salt at a concentration of 1.6 mol/L to 3.2 mol/L inclusive. The step of impregnation with the ionic liquid electrolyte is the step of impregnating the positive-electrode active material layer or the negative-electrode active material layer with the ionic liquid electrolyte at a temperature of 50° C. to 100° C. inclusive.
Abstract:
The present invention provides a positive electrode for non-aqueous electrolyte secondary battery, having novel overcharge protection functions. The present invention provides a positive electrode for non-aqueous electrolyte secondary battery, comprising a carbon layer and a positive-electrode active material layer provided on the carbon layer, wherein the carbon layer includes graphitizable carbon.
Abstract:
A positive electrode for a nonaqueous electrolyte secondary battery according to the present invention is provided with a porous positive electrode active material layer that contains a positive electrode active material. The positive electrode active material layer is formed so that a logarithmic differential pore volume distribution curve thereof, which shows the relation between pore diameter and pore volume of pores in the positive electrode active material layer, is a single-peak type curve. The distribution curve has a main peak having a full width at half maximum of from 0.001 μm to 0.05 μm inclusive, and the sum of the pore volumes of the pores within a pore diameter range corresponding to the full width at half maximum is 70% or more of the total pore volume.
Abstract:
A method for producing a non-aqueous electrolyte secondary battery according to the present invention is characterized in that the method comprises the steps of: placing an electrode body into an outer casing, the electrode body having a folded-separator structure or a wound structure in which a positive electrode including a positive-electrode active material and a negative electrode including a negative-electrode active material are stacked with a separator interposed therebetween; placing a non-aqueous electrolyte free of a flame retardant into the outer casing; charging the electrode body by applying a voltage between the positive electrode and the negative electrode placed in the outer casing; placing a flame retardant into the outer casing; and sealing the outer casing, wherein the step of charging is a step of charging the electrode body with the state in which the surface of the positive-electrode active material and the surface of the negative-electrode active material are in contact with the non-aqueous electrolyte substantially free of the flame retardant.