Abstract: This application relates to a bottom support for battery cell, a battery cell, a battery, and an electric device. The bottom support is configured for supporting a jelly roll, and the bottom support includes a bottom plate, where the bottom plate includes a central region and a peripheral region surrounding the central region. The bottom plate is constructed to form at least one recessed group, and a recessed area increases gradually among the recessed group(s) in a direction from the peripheral region to the central region of the bottom plate. The bottom support for battery cell, the battery cell, the battery, and the electric device provided in this application reduce the probability of thermal runaway in the battery cell.

Abstract: A method for detecting defects on a wafer including the steps of obtaining a reference image of a chip pattern formed on a reference wafer, using a computer algorithm to analyze the reference image to produce a division map for the chip pattern; setting respective thresholds for divisions of the division map, obtaining a comparison data between a test image of the chip pattern formed on a test wafer and the reference image, using the division map and the thresholds to examine the comparison data to identify a defect in the test image.