Disclosed is a lithium secondary battery, which is low in capacity loss after overdischarge, having excellent capacity restorability after overdischarge and shows an effect of preventing a battery from swelling at a high temperature.

Cathode active material for lithium secondary battery

Lithium rich and manganese rich lithium metal oxides are described that provide for excellent performance in lithium-based batteries. The specific compositions can be engineered within a specified range of compositions to provide desired performance characteristics. Selected compositions can provide high values of specific capacity with a reasonably high average voltage. Compositions of particular interest can be represented by the formula, x Li2MnO3 • (1-x) Li Niu+ΔMnu-ΔCowAyO2. The compositions undergo significant first cycle irreversible changes, but the compositions cycle stably after the first cycle.

Layer-layer lithium rich complex metal oxides with high specific capacity and excellent cycling

Positive electrode active materials are described that have a high tap density and high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li1+xNiαMnβCoγO2, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the battery.

Positive electrode materials for high discharge capacity lithium ion batteries

Disclosed is a method for preparing a lithium-metal composite oxide, the method comprising the steps of: (a) mixing an aqueous solution of one or more transition metal-containing precursor compounds with an alkalifying agent and a lithium precursor compound to precipitate hydroxides of the transition metals; (b) mixing the mixture of step (a) with water under supercritical or subcritical conditions to synthesize a lithium-metal composite oxide, and drying the lithium-metal composite oxide; and (c) subjecting the dried lithium-metal composite oxide either to calcination or to granulation and then calcination. Also disclosed are an electrode comprising the lithium-metal composite oxide, and an electrochemical device comprising the electrode. In the disclosed invention, a lithium-metal composite oxide synthesized based on the prior supercritical hydrothermal synthesis method is subjected either to calcination or to granulation and then calcination. Thus, unlike the prior dry calcination method or wet precipitation method, a uniform solid solution can be formed and the ordering of metals in the composite oxide can be improved. Accordingly, the lithium-metal composite oxide can show crystal stability and excellent electrochemical properties.

Preparation method of lithium-metal composite oxides

The present invention provides a positive electrode active material for lithium ion battery having good rate characteristics. The positive electrode active material for lithium ion battery has a layer structure expressed by a composition formula: Li x (Ni y M 1-y )O z , wherein M represents Mn and Co, x represents 0.9 to 1.2, y represents 0.6 to 0.9, and z represents 1.8 to 2.4. The positive electrode active material has a particle size ratio D50P/D50 of 0.60 or more, wherein D50 is the average secondary particle size of the positive electrode active material powder, and D50P is the average secondary particle size of the positive electrode active material powder after pressing at 100 MPa. The positive electrode active material contains 3% or less particles having a particle size of 0.4 μm or less in terms of the volume ratio after pressing at 100 MPa.

Positive electrode active material for lithium ion battery, positive electrode for lithium ion battery and lithium ion battery

Disclosed is a lithium-containing metal composite oxide comprising paramagnetic and diamagnetic metals, which satisfies any one of the following conditions: (a) the ratio of intensity between a main peak of 0 ± 10 ppm (IoPPm) and a main peak of 240 ± 140 ppm (I240pPm), Uoppm / l24oPPm), is less than 0.117 • Z wherein Z is the ratio of moles of the diamagnetic metal to moles of lithium; (b) the ratio of line width between the main peak of 0 ± 10 ppm (IoPPm) and the main peak of 240 + 140 ppm (I24oPPm), (W24oPPm / WOppm), is less than 21.45; and (c) both the conditions (a) and (b), the peaks being obtained according to the 7Li-NMR measurement conditions and means disclosed herein. Also, an electrode comprising the lithium-containing metal composite oxide, and an electrochemical device comprising the electrode are disclosed. The lithium-containing multicomponent metal composite oxide shows crystal stability and excellent physical properties as a result of an improved ordering structure of metals, in which the components of the composite oxide are uniformly distributed. Thus, it can provide a battery having high capacity characteristics, long cycle life characteristics and improved rate characteristics.

Lithium-metal composite oxides and electrochemical device using the same

Disclosed are a method of coating the surface of metal oxide with ultrafine metal oxide particles and a coating produced thereby. Specifically, the method of coating the surface of metal oxide with ultrafine metal oxide particles, according to this invention, includes i) bringing metal (Ml) oxide into contact with an aqueous solution of a metal (M2) salt to be applied thereon, and ii) continuously mixing and reacting the contacted metal oxide with water at a reaction temperature of 200~700°C under pressure of 180~550 bar.

Coating method of metal oxide superfine particles on the surface of metal oxide and coating produced therefrom

The present invention relates to manufacturing methods of fine cerium oxide particles and its slurry for shallow trench isolation process of semiconductor. To increase of the removal selectivity, an aqueous solution of additives consists of polyacrylic acid and amine compounds is added the cerium oxide slurry. The polishing slurry have a high particle stability and removal selectivity, and also less scratches after chemical mechanical polishing of semiconductor.

Manufacturing methods of fine cerium oxide particles and its slurry for shallow trench isolation process of semiconductor

Disclosed are a concentrate of fine ceria particles for chemical mechanical polishing, and a method of preparing the same. The method includes reacting a reactant mixture comprising i) water, ii) an aqueous solution of water-soluble cerium salt compound, and iii) ammonia or ammonium salt at a reaction temperature of 250-700 ? under a reaction pressure of 180-550 bar for 0.01 sec to 10 min in a continuous reactor to obtain a solution containing the fine ceria particles, the cerium salt compound being contained at an amount of 0.01 to 20 wt% in the reactant mixture; and concentrating the solution containing the fine ceria particles in a concentrator having a filter with a pore size of 0.01 to 10 ? . The concentrate is advantageous in that a CMP slurry and a dispersing solution are easily produced by diluting the concentrate and adding an additive to the concentrate.

Wan-Jae Myeong

Papers

Lithium-metal composite oxides and electrochemical device using the same

Coating method of metal oxide superfine particles on the surface of metal oxide and coating produced therefrom

Manufacturing methods of fine cerium oxide particles and its slurry for shallow trench isolation process of semiconductor

Concentrate of fine ceria particles for chemical mechanical polishing and preparing method thereof