A mixed powder for an all-solid-state lithium-ion battery, which is composed of a positive electrode active material for a lithium-ion battery and a solid electrolyte, wherein the positive electrode active material for a lithium-ion battery is composed of particles containing crystals of a lithium metal composite oxide, and the lithium metal composite oxide has a layered structure and contains at least Li and a transition metal, wherein the positive electrode active material for a lithium-ion battery has a particle diameter distribution that satisfies the following Formula (1), and wherein the solid electrolyte has a particle diameter distribution that satisfies the following Formula (2):

[00001]$\left(\text{D90-D10}\right)/\text{D50}\le \text{1}\text{.5}$

[00002]$\left(\text{D90-D10}\right)/\text{D50}\le 2.0$

The present invention relates to a battery cell with improved safety and a method of manufacturing the same, and more particularly a battery cell configured such that an electrode assembly including a positive electrode (200) and a negative electrode (300) located so as to be opposite each other in the state in which a separator (400) is interposed therebetween is received in a cell case (100), wherein the positive electrode (200) includes a positive electrode plate (210) and a positive electrode active material layer (220) provided on one surface and/or the other surface of the positive electrode plate (210), the negative electrode (300) includes a negative electrode plate (310) and a negative electrode active material layer (320) provided on one surface and/or the other surface of the negative electrode plate (310), the positive electrode active material layer (220) includes a first flat portion (221) and a first inclined portion (222) provided at each of opposite sides of the first flat portion (221), and the negative electrode active material layer (320) includes a second flat portion (321) and a second inclined portion (322) provided at each of opposite sides of the second flat portion (321) and a method of manufacturing the same.

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li.sub.1+aNi.sub.bMn.sub.cCo.sub.dTi.sub.eM.sub.fO.sub.2+α, and has an atomic ratio Ti.sup.3+/Ti.sup.4+ between Ti.sup.3+ and Ti.sup.4+, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and a are numbers satisfying −0.1≤a≤0.2, 0.7<b≤0.9, 0≤c<0.3, 0≤d<0.3, 0<e≤0.25, 0≤f<0.3, b+c+d+e+f=1, and −0.2≤α≤0.2.

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li.sub.1+aNi.sub.bMn.sub.cCo.sub.dTi.sub.eM.sub.fO.sub.2+α, and has an atomic ratio Ti.sup.3+/Ti.sup.4+ between Ti.sup.3+ and Ti.sup.4+, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and a are numbers satisfying −0.1≤a≤0.2, 0.7<b≤0.9, 0≤c<0.3, 0≤d<0.3, 0<e≤0.25, 0≤f<0.3, b+c+d+e+f=1, and −0.2≤α≤0.2.

A lithium secondary battery includes a cathode formed of a cathode active material including a lithium metal oxide particle having a concentration gradient, and a coating formed on the lithium metal oxide particle, the coating including aluminum, titanium and zirconium, an anode, and a separator interposed between the cathode and the anode. The cathode active material includes 2,000 ppm to 4,000 ppm of aluminum, 4,000 ppm to 9,000 ppm of titanium and 400 ppm to 700 ppm of zirconium, based on the total weight of the cathode active material. The performance of the secondary battery may be maintained under a high temperature condition.

A lithium secondary battery includes a cathode formed of a cathode active material including a lithium metal oxide particle having a concentration gradient, and a coating formed on the lithium metal oxide particle, the coating including aluminum, titanium and zirconium, an anode, and a separator interposed between the cathode and the anode. The cathode active material includes 2,000 ppm to 4,000 ppm of aluminum, 4,000 ppm to 9,000 ppm of titanium and 400 ppm to 700 ppm of zirconium, based on the total weight of the cathode active material. The performance of the secondary battery may be maintained under a high temperature condition.

The process of making a lithium ion battery cathode comprises the step of forming a slurry of an active material, a nano-size conductive agent, a binder polymer, a solvent and a dispersant. The solvent consists essentially of one or more of a compound of Formula 1, 2, or 3, and the dispersant comprises an ethyl cellulose.

The process of making a lithium ion battery cathode comprises the step of forming a slurry of an active material, a nano-size conductive agent, a binder polymer, a solvent and a dispersant. The solvent consists essentially of one or more of a compound of Formula 1, 2, or 3, and the dispersant comprises an ethyl cellulose.

A negative electrode slurry and a method of preparing the same. The negative electrode slurry includes lithium titanium oxide (LTO), a carboxylic acid-containing polymer dispersant, a binder, and an aqueous solvent. The carboxylic acid-containing polymer dispersant has a weight average molecular weight (Mw) of 2,500 g/mol to 500,000 g/mol and is present in an amount of 1.5 parts by weight to 20 parts by weight with respect to 100 parts by weight of the lithium titanium oxide.

A lithium cobalt-based oxide cathode active material powder having: —a primary phase comprising Li, Co, and O, and —a secondary phase comprising LiNaSO.sub.4, wherein the content of said LiNaSO.sub.4 secondary phase in said powder is of at least 0.4 wt. % and inferior or equal to 1.1 wt. % with respect to a total weight of the cathode active material powder, said cathode active material powder being characterized in that it has a S/Na atomic ratio superior or equal to 0.80 and inferior or equal to 1.20.