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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsYasutaka Kogetsu, Kazuyoshi Honda, Toshitada Sato, Hiroshi Yoshizawa
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A negative electrode for a lithium ion secondary battery including a current collector and an active material layer carried on the current collector, wherein the active material layer includes a first layer and a second layer alternately laminated in a thickness direction of the active material layer, and wherein the first layer includes silicon or silicon and a small amount of oxygen and the second layer includes silicon and a larger amount of oxygen than the first layer. With the use of the negative electrode, it is possible to provide a high capacity lithium ion secondary battery having excellent high rate charge/discharge characteristics and superior cycle characteristics.
A negative electrode for a lithium ion secondary battery comprising a current collector and an active material layer carried on said current collector,
A method for producing a negative electrode for a lithium ion secondary battery comprising a step of supplying silicon atoms to a current collector by sputtering or vapor deposition using a silicon target through an area into which oxygen gas is intermittently introduced, to form an active material layer comprising a first layer comprising silicon or silicon and a small amount of oxygen and a second layer comprising silicon and a larger amount of oxygen than said first layer alternately laminated therein.
A method for producing a negative electrode for a lithium ion secondary battery comprising a step of continuously evaporating a silicon target and a silicon oxide target by sputtering or vapor deposition to supply silicon atoms to a current collector and supply silicon atoms and oxygen atoms to said current collector, respectively, while alternately blocking the supply of the silicon atoms and the supply of the silicon atoms and the oxygen atoms to said current collector at certain time intervals, so that the supply of the silicon atoms to said current collector and the supply of the silicon atoms and the oxygen atoms to said current collector are alternated to form a first layer containing only silicon or silicon and a small amount of oxygen and a second layer containing silicon and a larger amount of oxygen than the first layer, respectively, said first and second layers being alternately laminated on the current collector.
A method for producing a negative electrode for a lithium ion secondary battery comprising a step of alternately evaporating a silicon target and a silicon oxide target by sputtering or vapor deposition at certain time intervals to alternately supply silicon atoms to a current collector from said silicon target and silicon atoms and oxygen atoms to said current collector from said silicon oxide target, thereby forming a first layer containing only silicon or silicon and a small amount of oxygen and a second layer containing silicon and a larger amount of oxygen than said first layer alternately laminated on said current collector.
Dependencies are inferred from the claim text.