ELECTRICAL ENERGY STORAGE MODULE AND SPACER USED FOR THE SAME

An electrical energy storage module disclosed herein includes first and second electrical energy storage devices, and a spacer. The spacer includes a base part, a first uneven structure that is provided on a first surface of the base part and includes a plurality of first protrusion parts and a first depression part, and a second uneven structure that is provided on a second surface of the base part and includes a second protrusion part. The second protrusion part of the second uneven structure is provided at a position corresponding to the first depression part of the first uneven structure.