Method for testing maximum compaction density of pole piece of material

The invention relates to a method for testing the maximum compaction density of a pole piece of a material, in particular to an accurate method for testing the maximum compaction density of the pole piece of a lithium ion battery material. The method comprises the following steps of: taking a plurality of points on a rolled pole piece along the direction parallel to the short side of the pole piece, and if the thickness difference is less than or equal to 1 mu m, performing a folding test on the pole piece along a line passing the points; and analyzing a plurality of compaction density data until results of at least ten-time tests pass the folding test under certain compaction density P1, and determining that P1 is the maximum compaction density of the pole piece of the material when results of at most ten-time tests do not pass the folding test. The method is easy to implement, test results are accurate, stable and reliable, and the misjudgment of the material performance brought by measurement errors of the