A positive active material for a rechargeable lithium battery includes a first compound represented by Chemical Formula 1, and a second compound having a smaller particle diameter than the first compound and represented by Chemical Formula 2, wherein the first compound and the second compound have a Ni content of about 50 at % to about 60 at % based on a total amount of metal elements excluding Li. A rechargeable lithium battery including the first compound and the second compound satisfies Relation 1:
V.sub.s<V.sub.1≤3.6.  [Relation 1]
In Relation 1, V.sub.1 is a voltage value at a point where a tangent line to a value corresponding to 50% of the first peak value intersects the line dQ/dV=0, and V.sub.s is a charge start voltage, as determined from a differential capacity (dQ/dV)-voltage charge/discharge plot.

What are provided are a positive electrode for a lithium-ion battery capable of suppressing the generation of carbon dioxide while increasing the battery capacity of the lithium-ion battery, a lithium-ion battery and a method for producing a positive electrode for a lithium-ion battery. A positive electrode for a lithium-ion battery having a positive electrode current collector and a positive electrode active material layer, in which the positive electrode active material layer has a positive electrode mixture containing the positive electrode active material, and the positive electrode mixture contains lithium carbonate in a range of 9% by mass or more and 20% by mass or less with respect of the total weight thereof.

The present disclosure relates to a stretchable electrode, a method for preparing the same and a stretchable battery including the stretchable electrode. The stretchable electrode of the present disclosure, which is prepared by crosslinking a hydroxyl-functionalized fluorine-based polymer binder physically using a ketone-based solvent or chemically with a crosslinking agent, has superior stretchability, has improved interfacial adhesivity to an active material through Fenton's oxidation, exhibits improved stability under various mechanical deformations of the electrode such as stretching, etc. and can uniformly maintain the electrical conductivity, battery capacity and charge-discharge performance of the electrode.

In addition, the stretchable battery of the present disclosure, which includes the stretchable electrode, a stretchable current collector, a stretchable separator and a stretchable encapsulant, has improved stretchability and superior battery stability under various deformations due to high degree of freedom of structures and materials. In addition, the stretchable battery of the present disclosure can be prepared as a fiber battery by printing an electrode and a current collector sequentially on both sides of a stretchable fabric, which can be worn, e.g., around sleeves due to superior stretchability and high structural degree of freedom and retains high battery performance and mechanical stability even under mechanical deformation. Therefore, it can be applied to a mobile display for a health monitoring system or a smartwatch.

The present application relates to an electrochemical device. Specifically, the present application provides a cell, wherein the cell is formed by winding or stacking a first electrode and a second electrode which are arranged at an interval, and a separator is disposed between the first electrode and the second electrode. Wherein the first electrode includes a first current collector, and the first current collector includes a coated region coated with a first active material and an uncoated region without the first active material; the uncoated region is at least partially provided with an insulating layer. The adhesion between the insulating layer and the first current collector is not less than about 0.5 N/m. The electrochemical device provided by the present application has improved safety performance.

The present application relates to an electrochemical device. Specifically, the present application provides a cell, wherein the cell is formed by winding or stacking a first electrode and a second electrode which are arranged at an interval, and a separator is disposed between the first electrode and the second electrode. Wherein the first electrode includes a first current collector, and the first current collector includes a coated region coated with a first active material and an uncoated region without the first active material; the uncoated region is at least partially provided with an insulating layer. The adhesion between the insulating layer and the first current collector is not less than about 0.5 N/m. The electrochemical device provided by the present application has improved safety performance.

The present disclosure relates to a positive electrode active material, a preparing method therefor, and a lithium secondary battery including same. A positive electrode active material according to an embodiment comprises: a core including a lithium nickel composite oxide represented by Chemical Formula 1; and a surface layer present on the core and including at least one of a water-soluble ammonium-based organic compound and a water-soluble amine-based organic compound. The details of Chemical Formula 1 are as defined in the specification.

The present disclosure relates to a positive electrode active material, a preparing method therefor, and a lithium secondary battery including same. A positive electrode active material according to an embodiment comprises: a core including a lithium nickel composite oxide represented by Chemical Formula 1; and a surface layer present on the core and including at least one of a water-soluble ammonium-based organic compound and a water-soluble amine-based organic compound. The details of Chemical Formula 1 are as defined in the specification.

A strip-shaped electrode sheet includes an electrode foil including a strip-shaped foil exposed portion in which the electrode foil is exposed, a strip-shaped active material layer extending in a longitudinal direction, and a strip-shaped insulator layer containing insulating resin and formed on an insulator-layer support portion along a one-side layer edge portion of the active material layer and between the foil exposed portion of the electrode foil and an active-material-layer support portion. The insulator layer is located lower than a top face of the active material layer toward the electrode foil and includes a slant coating portion covering at least a lower portion of a one-side slant portion of the active material layer and a foil coating portion extending from the slant coating portion in a width-direction one side and covering the insulator-layer support portion of the electrode foil.

A strip-shaped electrode sheet includes an electrode foil including a strip-shaped foil exposed portion in which the electrode foil is exposed, a strip-shaped active material layer extending in a longitudinal direction, and a strip-shaped insulator layer containing insulating resin and formed on an insulator-layer support portion along a one-side layer edge portion of the active material layer and between the foil exposed portion of the electrode foil and an active-material-layer support portion. The insulator layer is located lower than a top face of the active material layer toward the electrode foil and includes a slant coating portion covering at least a lower portion of a one-side slant portion of the active material layer and a foil coating portion extending from the slant coating portion in a width-direction one side and covering the insulator-layer support portion of the electrode foil.

Provided are a battery-level Ni—Co—Mn mixed solution and a preparation method for a battery-level Mn solution, the steps thereof comprising: acid dissolution (S1), alkalization to remove impurities (S2), synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), synergistic extraction (S5), and refining extraction (S6). The steps of deep ageing to remove impurities (S4) and synergistic extraction (S5) comprise: performing deep ageing on a filtrate obtained from the step of synchronous precipitation of calcium, magnesium, and lithium (S3), and after performing filtration to remove impurities, obtaining an aged filtrate; using P204 to extract the aged filtrate and obtain a loaded organic phase, and subjecting the loaded organic phase to staged back-extraction to obtain the battery-level Ni—Co—Mn mixed solution and a Mn-containing solution. By means of the cooperation between the multiple process steps of synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), and synergistic extraction (S5), the impurity content of the obtained battery-level Ni—Co—Mn mixed solution is significantly lowered, and the battery-level Ni—Co—Mn mixed solution can be directly used to prepare a lithium battery ternary precursor material. At the same time, the battery-level Mn solution can also be obtained, which is favorable for large-scale applications of the process and increasing economic benefits.