Polyolefin powder, extrusion molding material, separator, battery, electronic device, and mobile device

The polyolefin powder provided by the invention is easy to process, resistant to yellowing and excellent in film forming quality, and has the characteristics of relatively low hole closing temperature and relatively high film rupture temperature. The viscosity average molecular weight Mv of the polyolefin powder is more than 15 * 10 < 4 > and less than 300 * 10 < 4 >, the initial crystallization temperature is more than 108 DEG C and less than 120 DEG C, the yellowing resistance Mv1/Mv is more than or equal to 0.75, the polyolefin powder contains 10-30wt% of polyolefin powder with the particle size of more than 110 microns, the melt index is 10-30g/10min, the content of polyolefin powder with the particle size of less than 70 microns is 70-90wt%, and the melt index is less than or equal to 0.5 g/10min. By adjusting the yellowing resistance and particle size distribution of the polyolefin powder, the bright spot defect of the formed film material is improved, and the safety of the battery cell can be improved.