A power storage device with reduced initial irreversible capacity is provided. The power storage device includes a positive electrode including a positive electrode current collector and a positive electrode active material layer, a negative electrode including a negative electrode current collector and a negative electrode active material layer, and an electrolyte solution. In the negative electrode active material layer, the content percentage of a carbon material with an R value of 1.1 or more is less than 2 wt %. The R value refers to a ratio of a peak intensity I1360 to a peak intensity I1580 (I1360/I1580). The peak intensity I1360 and the peak intensity I1580 are observed by Raman spectrometry at a Raman shift of 1360 cm−1 and a Raman shift of 1580 cm−1, respectively. The electrolyte solution contains a lithium ion and an ionic liquid composed of an organic cation and an anion.