CPC H01M 4/364 (2013.01) [H01M 4/133 (2013.01); H01M 4/134 (2013.01); H01M 4/366 (2013.01); H01M 4/661 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01)] | 9 Claims |
1. A negative electrode for a nonaqueous electrolyte secondary battery, the negative electrode comprising a negative electrode current collector and a negative electrode mixture layer formed on the negative electrode current collector,
the negative electrode mixture layer including
a first layer formed on the negative electrode current collector and including a negative electrode active material and a first binding agent, the negative electrode active material, which is in the first layer, including a carbon material A and a Si-containing compound, the first binding agent including polyacrylic acid or a salt thereof, and
a second layer formed on the first layer and including a negative electrode active material and a second binding agent, the negative electrode active material, which is in the second layer, including a carbon material B, the carbon material B having a tap density higher than a tap density of the carbon material A, wherein
a mass of the first layer relative to a mass of the negative electrode mixture layer is 50 mass % or greater and less than 90 mass %, and a mass of the second layer relative to the mass of the negative electrode mixture layer is greater than 10 mass % and 50 mass % or less,
a packing density of the second layer is lower than a packing density of the first layer,
a mass ratio between the carbon material A and the Si-containing compound in the first layer is within a range of 95:5 to 70:30, and
a concentration of the first binding agent in the first layer is higher than a concentration of the second binding agent in the second layer.
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