The Growth Mechanism of Lithium Dendrites and its Coupling to Mechanical Stress

This Supporting Information contains four additional figures (S1-S4). In Section A1, EDX data with maps for oxygen and carbon is displayed (Figure S1). Results from the growth of needles and loops are shown in Section A2 with the length vs. time development (Figure S2) and light microscopy images of a loop (Figure S3). The Section A3 is a discussion of the dependencies of length vs. time compared with the ionic depletion as described by calculated concentrations vs. time. In Section A4 a schematic of the atom insertion at the edge dislocation at an extra half-plane is shown (Figure S4).

SV1 video of needle growth at −0.05 mA cm−2

SV2 video of loop growth at −0.05 mA cm−2

In video SV3, an SEM image of a loop is depicted together with the Kikuchi patterns recorded at different positions. The green square in the SEM image indicates the electron beam position of the corresponding Kikuchi pattern displayed on the right. Lithium has little interaction with electrons, and therefore, the backscattered intensity is very low and the diffraction patterns exhibit noise. Nevertheless, lines are discernable, which indicate crystallinity. The orientation of the lines correlates with the orientation of the reciprocal lattice and hence can be used to indicate the orientation of different regions of the loop. The fact that the diffraction patterns change before and after kinks show that the crystal orientations change, which clearly indicates that there must be grain boundaries between the diffraction spots. Points with the same lattice orientation are designates with the same letter (a, b, c, d).