Patent ID: 8293405

Claim:
A rechargeable lithium ion battery, comprising: a positive electrode having a positive electrode mixture layer comprising a positive electrode active material and a binder resin; a negative electrode having a negative electrode mixture layer comprising a negative electrode active material and a binder resin; and a separator disposed between the positive electrode and the negative electrode, wherein the positive electrode mixture layer further comprises 1 part by weight or more and 20 parts by weight or less of collapsed hollow resin particles with respect to 100 parts by weight of the positive electrode active material, and/or the negative electrode mixture layer comprises 1 part by weight or more and 50 parts by weight or less of collapsed hollow resin particles with respect to 100 parts by weight of the negative electrode active material, the collapsed hollow resin particles being collapsed product of hollow resin particles each having an empty space therein, and when a scanning electron microscope image of the surface of the positive electrode mixture layer or the negative electrode mixture layer containing the collapsed hollow resin particles is reduced to a 256 gray-scale image and then is binarized into black pixels and white pixels at a threshold of 70, a ratio of the total area of the black pixels to the total area of entire pixels is 10% or more and 20% or less.