Secondary battery and power-consuming device

Abstract

A secondary battery characterized in that it comprises a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte solution, wherein the positive electrode sheet comprises a positive electrode active material layer comprising a positive electrode active material and a positive lithium refill, wherein the positive lithium refill contains large particles, each containing several small particles, and wherein the ratio between the average particle size of the small particles and the average particle size of the large particles is a; wherein a scanning electron microscopy (SEM) cross-sectional image of the positive lithium refill is recorded, wherein cracks are visible in the SEM cross-sectional image at least between some of the small particles, and the average width of the cracks is b µm; wherein the secondary battery satisfies the following conditions: 0.1 ≤ a / b ≤ 1.7 and 0.05 ≤ a ≤ 0.4.