Provided are various embodiments of a positive electrode for a secondary battery, which in one embodiment includes a first positive electrode material mixture layer formed on a positive electrode collector, and a second positive electrode material mixture layer formed on the first positive electrode material mixture layer, wherein the first positive electrode material mixture layer has an operating voltage of 4.25 V to 6.0 V and includes an active material for overcharge which generates lithium and gas during charge; a method of preparing such a positive electrode for a secondary battery; and a lithium secondary battery including such a positive electrode.

Provided are various embodiments of a positive electrode for a secondary battery, which in one embodiment includes a first positive electrode material mixture layer formed on a positive electrode collector, and a second positive electrode material mixture layer formed on the first positive electrode material mixture layer, wherein the first positive electrode material mixture layer has an operating voltage of 4.25 V to 6.0 V and includes an active material for overcharge which generates lithium and gas during charge; a method of preparing such a positive electrode for a secondary battery; and a lithium secondary battery including such a positive electrode.

The present disclosure relates to a negative electrode material that may be used as a negative electrode active material. The negative electrode material includes a silicon oxide material containing a metal (M)-silicate and a carbonaceous material. According to an embodiment of the present disclosure, the negative electrode material may include the silicon oxide material containing a metal (M)-silicate and the carbonaceous material mixed with each other at a predetermined ratio. The negative electrode active material according to the present disclosure comprises a composite of a carbonaceous material having a broad particle size distribution with a metal-silicate, and thus provides improved electrical conductivity and life characteristics.

The present disclosure relates to a negative electrode material that may be used as a negative electrode active material. The negative electrode material includes a silicon oxide material containing a metal (M)-silicate and a carbonaceous material. According to an embodiment of the present disclosure, the negative electrode material may include the silicon oxide material containing a metal (M)-silicate and the carbonaceous material mixed with each other at a predetermined ratio. The negative electrode active material according to the present disclosure comprises a composite of a carbonaceous material having a broad particle size distribution with a metal-silicate, and thus provides improved electrical conductivity and life characteristics.

A positive-electrode material for a lithium secondary battery is provided. The material includes a lithium oxide compound or a complex oxide as reactive substance. The material also includes at least one type of carbon material, and optionally a binder. A first type of carbon material is provided as a coating on the reactive substance particles surface. A second type of carbon material is carbon black. And a third type of carbon material is a fibrous carbon material provided as a mixture of at least two types of fibrous carbon material different in fiber diameter and/or fiber length. Also, a method for preparing the material as well as lithium secondary batteries including the material is provided.

A positive-electrode material for a lithium secondary battery is provided. The material includes a lithium oxide compound or a complex oxide as reactive substance. The material also includes at least one type of carbon material, and optionally a binder. A first type of carbon material is provided as a coating on the reactive substance particles surface. A second type of carbon material is carbon black. And a third type of carbon material is a fibrous carbon material provided as a mixture of at least two types of fibrous carbon material different in fiber diameter and/or fiber length. Also, a method for preparing the material as well as lithium secondary batteries including the material is provided.

The present disclosure provides a non-aqueous electrolyte including an additive including a repeating unit represented by Formula 1 and a repeating unit represented by Formula 2 below:

##STR00001##

##STR00002##

wherein X, R, R.sub.1 and R.sub.2 are described herein.

The present disclosure provides a non-aqueous electrolyte including an additive including a repeating unit represented by Formula 1 and a repeating unit represented by Formula 2 below:

##STR00001##

##STR00002##

wherein X, R, R.sub.1 and R.sub.2 are described herein.

A battery includes a positive electrode including a positive electrode active material, a negative electrode, and an electrolytic solution including a nonaqueous solvent. The positive electrode active material includes a compound having a crystal structure belonging to a space group FM3-M and represented by Compositional Formula (1): Li.sub.xMe.sub.yO.sub.αF.sub.β, where, Me is one or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and Cr; and subscripts x, y, α, and β satisfy the following requirements: 1.7≤x≤2.2, 0.8≤y≤1.3, 1≤α≤2.5, and 0.5≤β≤2. The nonaqueous solvent includes a solvent having at least one fluoro group.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a lithium-nickel composite oxide. The negative electrode includes a lithium-titanium composite oxide. The electrolytic solution includes a dinitrile compound and a carboxylic acid ester. A ratio of a capacity per unit area of the positive electrode to a capacity per unit area of the negative electrode is greater than or equal to 100% and less than or equal to 120%. A ratio of a number of moles of the dinitrile compound to a number of moles of the carboxylic acid ester is greater than or equal to 1% and less than or equal to 4%.