A secondary battery with excellent cycle performance is provided. The secondary battery is an all-solid-state battery including a positive electrode current collector layer, a base film, a positive electrode active material layer, a buffer layer, and a solid electrolyte layer. The base film contains titanium nitride. The positive electrode active material layer contains lithium cobalt oxide. The buffer layer contains titanium oxide. The solid electrolyte layer contains a titanium compound. By using titanium oxide for the buffer layer, a side reaction between the positive electrode active material layer and the solid electrolyte layer can be suppressed, and cycle performance can be improved.

Embodiments of the present invention relate to a cathode active material, a method for manufacturing the same, and a lithium secondary battery including the same.

According to an embodiment, a cathode active material can be provided, the cathode active material comprising: a lithium metal oxide including a core and a shell disposed on a surface of the core; and a coating layer disposed on a surface of the lithium metal oxide, wherein a c value that satisfies Equation 1 and is in a range of 0.3 to 0.7, and the core and the shell have a layered crystalline structure.

c=b/a  [Equation 1]

(in Equation 1, a is a peak at 530 to 533 eV and b is a peak at 528 to 531 eV in an XPS spectrum of the coating layer)

Embodiments of the present invention relate to a cathode active material, a method for manufacturing the same, and a lithium secondary battery including the same.

According to an embodiment, a cathode active material can be provided, the cathode active material comprising: a lithium metal oxide including a core and a shell disposed on a surface of the core; and a coating layer disposed on a surface of the lithium metal oxide, wherein a c value that satisfies Equation 1 and is in a range of 0.3 to 0.7, and the core and the shell have a layered crystalline structure.

c=b/a  [Equation 1]

(in Equation 1, a is a peak at 530 to 533 eV and b is a peak at 528 to 531 eV in an XPS spectrum of the coating layer)

Provided are a positive electrode active material for a lithium secondary battery, a method of preparing the same, and a lithium secondary battery including the same.

According to an exemplary embodiment, a positive electrode active material for a lithium secondary battery which includes lithium metal oxide particles and a coating layer placed on at least a part of a surface of the lithium metal oxide particles may be provided, wherein the coating layer includes B, LiOH, Li.sub.2CO.sub.3, and Li.sub.2SO.sub.4.

A lithium ion battery according to the present invention comprises a positive electrode, a negative electrode, a positive electrode lead that is connected to the positive electrode, an insulation tape that covers the positive electrode lead, and an electrolyte solution. The insulation tape comprises a base material layer that is mainly composed of an organic material, and a filler layer that is provided on the base material layer; the filler layer contains an oxide compound of an alkaline earth metal; and the electrolyte solution contains fluorine.

A lithium ion battery according to the present invention comprises a positive electrode, a negative electrode, a positive electrode lead that is connected to the positive electrode, an insulation tape that covers the positive electrode lead, and an electrolyte solution. The insulation tape comprises a base material layer that is mainly composed of an organic material, and a filler layer that is provided on the base material layer; the filler layer contains an oxide compound of an alkaline earth metal; and the electrolyte solution contains fluorine.

This non-aqueous electrolyte secondary battery comprises an electrode body in which a first separator, a positive electrode plate, a second separator, and a negative electrode plate are layered and coiled for 10 or more turns. The electrode body includes: a flat section in which the outer peripheral surface is flat; and two curved surface sections which are disposed at both ends in a first direction of the flat section and in which the outer peripheral surface is curved. The non-aqueous electrolyte secondary battery includes: a winding-end tape that is adhered to the outermost peripheral surface of the electrode body; and a positive electrode protective tape that is adhered to a winding-start-side end section on the inner peripheral side of the positive electrode plate. The winding-end tape is disposed on one of the two curved surface sections.

This non-aqueous electrolyte secondary battery comprises an electrode body in which a first separator, a positive electrode plate, a second separator, and a negative electrode plate are layered and coiled for 10 or more turns. The electrode body includes: a flat section in which the outer peripheral surface is flat; and two curved surface sections which are disposed at both ends in a first direction of the flat section and in which the outer peripheral surface is curved. The non-aqueous electrolyte secondary battery includes: a winding-end tape that is adhered to the outermost peripheral surface of the electrode body; and a positive electrode protective tape that is adhered to a winding-start-side end section on the inner peripheral side of the positive electrode plate. The winding-end tape is disposed on one of the two curved surface sections.

Provided is a surface-treated copper foil in which in order to avoid failures of electronic parts by corrosion, a high bond strength between an electrolytic copper foil and a resin base material can be maintained even when the surface-treated copper foil is exposed to corrosive gases and microparticles, and a method for manufacturing the same. The surface-treated copper foil of the present invention comprises an electrolytic copper foil, a roughened layer covering at least one surface side of the electrolytic copper foil, and a rust preventive layer further covering the roughened layer, wherein the rust preventive layer is at least one surface of the surface-treated copper foil; the rust preventive layer comprises at least a nickel layer; and the thickness of the nickel layer is 0.8 to 4.4 g/m.sup.2 in terms of mass per unit area of nickel; and the noncontact roughness Spd of the rust preventive layer is 1.4 to 2.6 peaks/μm.sup.2 and the surface roughness RzJIS of the rust preventive layer is 1.0 to 2.5 μm. The method for manufacturing the surface-treated copper foil forms the roughened layer having higher roughnesses than the noncontact roughness Spd and surface roughness RzJIS on one surface of the electrolytic copper foil, and thereafter forming the rust preventive layer meeting the predetermined condition.

The present exemplary embodiments relate to a positive electrode active material, a manufacturing method thereof, and a lithium secondary battery including the same. A positive active material for a lithium secondary battery according to an exemplary embodiment is a lithium metal oxide particle in the form of secondary particles including a plurality of primary particles: a first coating layer positioned on at least a part of the surface of the primary particle, and a second coating layer positioned over at least a portion of the secondary particle surface, the first coating layer comprising a first niobium compound, the second coating layer comprising the first niobium compound and a second niobium compound having a composition different from the first niobium compound.