ELECTRODE FOR SECONDARY BATTERY AND SECONDARY BATTERY

An object of the present invention is to obtain an electrode for secondary battery capable of realizing a secondary battery having a high output and a long lifespan using a small amount of conductive auxiliary. The present invention is an electrode for secondary battery which has a mixture layer containing graphene and active material particles for secondary battery containing at least lithium and nickel and in which an average aspect ratio of conductive material portions in a cross section of the electrode for secondary battery identified by the following method is 2.0 or more: the method for identifying a conductive material portion: (1) a spreading resistance value at a mixture layer portion is acquired by scanning spreading resistance microscopy, and (2) a total data number of the spreading resistance values is taken as N, the spreading resistance values are sorted in ascending order, and a 0.1Nth spreading resistance value (rounded down to a nearest decimal point of 0.1N) is taken as R, and binarization processing is performed on two-dimensional data of a spreading resistance value using 0.7R as a threshold value and a portion having a resistance value of 0.7R or less in a binarized image attained is taken as a conductive material portion.