ELECTRICAL DEVICE

摘要

Provided is a means which is capable of achieving satisfactory rate characteristics, while sufficiently making use of a high capacity that is a characteristic of a solid solution positive electrode active material in an electrical device such as a lithium ion secondary battery having a positive electrode which uses a solid solution positive electrode active material.;An electrical device having a power generating element which includes a positive electrode where a positive electrode active material layer containing a positive electrode active material is formed on a surface of a positive electrode current collector, a negative electrode where a negative electrode active material layer containing a negative electrode active material is formed on a surface of a negative electrode current collector, and a separator, in which the coating amount of the negative electrode active material layer is set at 4 to 11 mg/cm2, the negative electrode active material layer contains a negative electrode active material represented by Formula (1), the positive electrode active material layer contains a positive electrode active material (a solid solution positive electrode active material) represented by Formula (2), and in that case, as a solid solution positive electrode active material to be contained in the positive electrode active material layer, a material represented by Formula (3) and having a particle surface that is provided with a certain amount of coating layer which is formed of an oxide or complex oxide of a metal that is selected from the group consisting of Al, Zr and Ti is used.

主权项

1. An electrical device comprising a power generating element containing
a positive electrode in which a positive electrode active material layer containing a positive electrode active material is formed on a surface of a positive electrode current collector, a negative electrode in which a negative electrode active material layer containing a negative electrode active material is formed on a surface of a negative electrode current collector, and a separator, wherein a coating amount of the negative electrode active material layer is 4 to 11 mg/cm2, the negative electrode active material layer contains a negative electrode active material represented by a following Formula (1):
[Mathematical Formula 1]α(Si-containing alloy)+β(carbon material)  (1) in the formula, α and β represent % by weight of each component in the negative electrode active material layer, and 80≦α+98, 3≦α≦40, and 40≦β≦95, the positive electrode active material layer contains a positive electrode active material represented by a following Formula (2):
[Mathematical Formula 2]e(solid solution positive electrode active material)  (2) in the formula, e represents % by weight of each component in the positive electrode active material layer, and 80≦e≦98, wherein the solid solution positive electrode active material has a composition represented by a following Formula (3):
[Mathematical Formula 3]Li1.5[NiaMnbCoc[Li]d]Oz  (3) in the formula, z represents an oxygen number for satisfying an atomic valence and a+b+c+d=1.5, 0.1≦d≦0.4, and 1.1≦[a+b+c]≦1.4, and a coating layer comprising oxide or composite oxide of a metal selected from the group consisting of Al, Zr, and Ti is formed on a surface of a particle of the solid solution positive electrode active material and a content of the oxide or composite oxide in the solid solution positive electrode active material is 0.1 to 3.0% by weight in terms of oxide.