| CPC H01M 4/0404 (2013.01) [H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] | 12 Claims |
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1. A cathode for a secondary battery which includes a cathode collector and a cathode mixture layer on the cathode collector, the cathode comprising:
a coating section at which the cathode mixture layer is formed with a uniform thickness, the coating section extending in both a longitudinal direction along a length of the cathode collector and in a lateral direction across a width of the cathode collector that is shorter than the length;
a non-coating section that is disposed on a side of the cathode collector that extends in the longitudinal direction and on which the cathode mixture layer is not formed; and
a cushioning section at which the cathode mixture layer is formed with a thickness of the cushioning section smaller than a thickness of the coating section at a first location between the coating section and the non-coating section;
wherein the cushioning section consists of only a first sloped region and a second sloped region,
wherein the thickness of the cathode mixture layer in the first sloped region of the cushioning section increases gradually at a constant first slope from a first point to a third point and at a constant second slope in the second sloped region from the third point to a second point,
wherein the first point is at a boundary between the non-coating section and the cushioning section,
wherein the second point is at a boundary between the cushioning section and the coating section,
wherein the third point is disposed between the first and second points, and
wherein a ratio of the thicknesses of the cushioning section at the third point and the second point is between 0.5 to 0.8
wherein the third point is spaced apart from the first point by 20% to 60% of a length from the first point to the second point on the collector.
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