From fracture mechanics, we develop a model to describe the dendrite trajectory under mechanical loading. We will use this model to interpret our experimental results, and later to provide criteria for deflecting dendrites (thus averting electrical shorting). Dendrites are modeled as slit-like metal-filled flaws initially oriented at angle 𝛽𝛽 from the horizontal (Fig. ) in a homogeneous and isotropic solid electrolyte. The planar electrolyte/electrode interface is held with fixed x-displacement. Metal plating into the flaw leads to a uniform pressure of 𝑃𝑃 normal to the flaw face. In the absence of any other stresses in the electrolyte, this plating-induced pressure 𝑃𝑃 causes the dendrite to propagate forward without kinking. When an additional load is applied to the solid electrolyte in the vertical direction (𝜎𝜎 𝑦𝑦𝑦𝑦 ), the energetically preferred path for dendrite propagation is at a kinked angle from its initial orientation, as seen in Fig. . The stress state in front of the crack tip crack is then a result of the superposition of the platinginduced pressure and the applied load. The most favorable propagation angle (𝜃𝜃 in Fig. ) maximizes the local stress intensity factor for an infinitesimal extension of the crack tip. The derivation underlying this model is detailed in Methods.