Abstract: An object of the present invention is to provide a method for manufacturing a secondary battery with enhanced insulating reliability without degrading the performance of an active material mixture layer formed on an electrode. The present invention provides a method for manufacturing a prismatic secondary battery (100) including a negative electrode (41) having a negative electrode current-collecting foil (411), a negative electrode mixture layer (412) formed thereon, and an insulating layer (413) formed on the negative electrode mixture layer (412). The method of the present invention includes a step of forming the negative electrode mixture layer (412) and the insulating layer (413) by concurrently applying an active material mixture slurry and an insulating layer dispersion liquid to the negative electrode current-collecting foil (411). Each ceramic particle (413a) has a plate shape with an aspect ratio greater than or equal to 2.0 and less than or equal to 5.0.

Abstract: A lithium ion secondary battery with increased durability and capacity includes a positive electrode, a negative electrode, and a separator. The positive electrode includes a current collector foil and an electrode mixture layer disposed on a surface of the current collector foil. The positive electrode mixture layer includes a superficial layer portion and a deep layer portion. The superficial layer portion opposes the negative electrode via the separator. The deep layer portion is disposed between the superficial layer portion and the current collector foil. The superficial layer portion contains positive electrode active material particles having an average particle diameter larger than an average particle diameter of positive electrode active material particles contained in the deep layer portion.

Abstract: An object of the present invention is to provide a method for manufacturing a secondary battery with enhanced insulating reliability without degrading the performance of an active material mixture layer formed on an electrode. The present invention provides a method for manufacturing a prismatic secondary battery (100) including a negative electrode (41) having a negative electrode current-collecting foil (411), a negative electrode mixture layer (412) formed thereon, and an insulating layer (413) formed on the negative electrode mixture layer (412). The method of the present invention includes a step of forming the negative electrode mixture layer (412) and the insulating layer (413) by concurrently applying an active material mixture slurry and an insulating layer dispersion liquid to the negative electrode current-collecting foil (411). Each ceramic particle (413a) has a plate shape with an aspect ratio greater than or equal to 2.0 and less than or equal to 5.0.

Abstract: Provided is a square secondary battery that is capable of reducing the amount of electrolyte compared to the related art. The square secondary battery includes a flat electrode group that is manufactured by winding positive and negative electrodes, a flat square battery can which stores the electrode group, a battery lid that seals an opening of the battery can, and an insulating member which is fixed to the battery lid and stored in the battery can. The square secondary battery includes a storage member made of a bag-like insulating sheet that has a volume smaller than the battery can, is stored in the battery can and stores the electrode group together with the electrolyte. The insulating member adheres to the battery lid to seal a space formed with respect to the battery lid, and is bonded to an opening of the storage member to seal the opening.

Abstract: The lithium secondary battery uses lithium or a compound containing lithium as an anode active material, and lithium nickel oxide as a cathode active material. This battery is produced to enhance the charge and discharge capacity. The lithium nickel oxide is prepared as follows. Nickel oxide which contains nickel of more than trivalence or a nickel salt which produces nickel of more than trivalence when heated, and lithium salt are mixed at an Li/Ni (molar salt ratio) of 1.0 to 1.5. After preheating the mixture, it is baked at a temperature of 680.degree. C. to 780.degree. C. in an oxygen atmosphere, thus producing a lithium nickel oxide. The primary differential absorption spectrum of the electron spin resonance of the lithium nickel oxide is a singlet (single line) when measured by use of an X band at a temperature of 77 K., and the line distance (.DELTA.Hpp) between the peaks is 140 mT or more.