Samsung Sdi Co., Inc.

Changwook Kim

Sooyoun Park

Jihyun Kim

Youngjin Park

Hyunjoo Je

Yongchan You

Dohyung Park

Sangin Park

Young Jin Park

Daehoe Lee

Eunsung Lee

Kyouyoon Sheem

Sangwoo Cho

The invention relates to a lithium secondary battery including a positive electrode, a negative electrode including a negative active material, and an electrolyte, wherein the positive electrode includes a first positive active material of a lithium manganese cobalt oxide in Chemical Formula 1, and a second positive active material of a lithium transition metal oxide that occludes and releases lithium ions; an average particle diameter (D50) of the first positive active material is smaller than an average particle diameter (D50) of the second positive active material; and the first positive active material has lower first charge/discharge efficiency than that of the negative active material and has an irreversible capacity during the first charge/discharge that is larger than an irreversible capacity during the first charge/discharge of the negative active material.

Lithium secondary battery

A composite positive electrode active material for a lithium secondary battery including a compound represented by Formula 1 below and a compound represented by Formula 2 below, and a lithium secondary battery employing a positive electrode that includes the composite positive electrode active material:LiNiCoMnMO&#x2003;&#x2003;Formula 1wherein, in Formula 1, ranges of M, a, x, and y are as defined in the detailed description above, andM[M(CN)]HO&#x2003;&#x2003;Formula 2wherein, in Formula 2, M, M, z, x, and n are as defined in the detailed description above.

Composite positive electrode active material for lithium secondary battery and lithium secondary battery comprising electrode including the composite positive electrode active material

A positive active material for a rechargeable lithium battery and a rechargeable lithium battery including the same are provided. The positive active material includes a lithium intercalation compound and a Si-containing TiOpresent on the surface of the compound. When TiOis present on the surface of the lithium intercalation compound, the rate characteristics and low temperature characteristics of batteries including the lithium intercalation compound may be improved. Further, when Si-containing TiOis present on the surface of the lithium intercalation compound, the cycle-life characteristic and high temperature storage characteristics of batteries including the lithium intercalation compound may be further improved, compared to batteries having only TiO. As such, the positive active material including Si-containing TiOprovides a rechargeable lithium battery having excellent rate capability, low temperature characteristics, cycle-life characteristics and high temperature storage characteristics.

Positive active material for rechargeable lithium battery and rechargeable lithium battery including the same

Provided are a positive active material, a positive electrode including the same, and a lithium secondary battery including the positive electrode. The positive active material includes lithium cobalt oxide containing a metal element, and the lithium cobalt oxide containing a metal element has a ratio of a peak intensity of the O3 phase to a peak intensity of the H1-3 phase, I/I, that is greater than 1 in a X-ray diffraction (XRD) analysis spectrum using Cu-K&#x3b1; radiation. Accordingly, a lithium secondary battery including the positive active material may have improved lifespan characteristics even at a high voltage.

Positive active material, positive electrode including the same, and lithium secondary battery including the positive electrode

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Yongin-si, South Korea

Changwook Kim