An electrolyte of a lithium-ion secondary battery and an application thereof. The electrolyte of the lithium-ion secondary battery includes an organic solution, a lithium salt, and an additive, and the additive comprises a borate compound. The electrolyte can be better applied to low-cobalt or cobalt-free positive electrode materials, improve the high-temperature cycle and storage performance of the lithium-ion batteries, and inhibit gas generation during high-temperature storage, thereby improving the comprehensive performance of the battery.

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.

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.

The propose method of manufacturing a solid-state lithium battery consists of preparing an anode coated with a solid-state electrolyte precursor and a cathode unit coated with solid-state electrolyte, both precursors containing a predetermined amount of a redundant water. The thus prepared anode unit and cathode unit are pressed to each other through their respective electrolyte precursor layers in a closed chamber at a predetermined elevated temperature and under a predetermined mechanical pressure, whereby an integral pre-final solid-state battery unit is formed. The manufacture of the battery is completed by inserting the prefinal product into a casing that leaves parts of the metal current collectors of the prefinal product exposed for use as a battery anode and a battery cathode.

The present invention provides a nanostructured titanic acid salt and a preparation process and use thereof. The process comprises preparing a dispersion containing titanium peroxy complex; slowly adding a metal compound to the dispersion containing the titanium peroxy complex to form a solution; adding an alcohol to the solution under normal temperature and normal pressure to produce the nanostructured titanic acid salt precursor precipitate in the solution, and separating the precipitate to obtain the titanic acid salt precursor; drying the precursor, and then heat treating it to obtain the nanostructured titanic acid salt product. The present invention provides a process for preparing a titanic acid salt with simple preparation process, easy control for process parameters and easy large-scale industrial production.

The present invention provides a nanostructured titanic acid salt and a preparation process and use thereof. The process comprises preparing a dispersion containing titanium peroxy complex; slowly adding a metal compound to the dispersion containing the titanium peroxy complex to form a solution; adding an alcohol to the solution under normal temperature and normal pressure to produce the nanostructured titanic acid salt precursor precipitate in the solution, and separating the precipitate to obtain the titanic acid salt precursor; drying the precursor, and then heat treating it to obtain the nanostructured titanic acid salt product. The present invention provides a process for preparing a titanic acid salt with simple preparation process, easy control for process parameters and easy large-scale industrial production.

A positive-electrode active material contains a lithium composite oxide containing at least one selected from the group consisting of F, Cl, N, and S. The crystal structure of the lithium composite oxide belongs to a space group C2/m. An XRD pattern of the lithium composite oxide comprises a first peak within the first range of 44 degrees to 46 degrees of a diffraction angle 2θ and a second peak within the second range of 18 degrees to 20 degrees of the diffraction angle 2θ. The ratio of the second integrated intensity of the second peak to the first integrated intensity of the first peak is within a range of 0.05 to 0.90.

A positive-electrode active material contains a lithium composite oxide containing at least one selected from the group consisting of F, Cl, N, and S. The crystal structure of the lithium composite oxide belongs to a space group C2/m. An XRD pattern of the lithium composite oxide comprises a first peak within the first range of 44 degrees to 46 degrees of a diffraction angle 2θ and a second peak within the second range of 18 degrees to 20 degrees of the diffraction angle 2θ. The ratio of the second integrated intensity of the second peak to the first integrated intensity of the first peak is within a range of 0.05 to 0.90.

An embodiment provides a binder for a non-aqueous electrolyte rechargeable battery including a copolymer (A) and a copolymer (B), wherein the copolymer (A) includes a unit (a-1) derived from a (meth)acrylic acid-based monomer, and a unit (a-2) derived from a (meth)acrylonitrile monomer, and the copolymer (B) includes a unit (b-1) derived from an aromatic vinyl-based monomer; and a unit (b-2) derived from an ethylenic unsaturated monomer which is at least one of an unsaturated carboxylic acid alkylester monomer, a (meth)acrylic acid-based monomer, a unsaturated carboxylic acid amide monomer, or combinations thereof.

According to one embodiment, a separator is provided. The separator includes a composite membrane. The composite membrane includes a substrate layer, a first composite layer, and a second composite layer. The first composite layer is located on one surface of the substrate layer. The second composite layer is located on the other surface of the substrate layer. The composite membrane has a coefficient of air permeability of 1×10.sup.−14 m.sup.2 or less. The first composite layer has a first surface and a second surface. The first surface is in contact with the substrate layer. The second surface is located on an opposite side to the first surface. Denseness of a portion including the first surface is lower than denseness of a portion including the second surface in the first composite layer.