In this study we investigated how Ag ions implanted into LLZTO affect crack growth, specifically induced by growing dendrites. First Ag ions were implanted in LLZTO using conditions determined by kinetic Monte Carlo simulations to introduce ions into a depth of up to 1 µm, with a concentration peak at 750 nm. Determination of the actual concentration distribution and concentration maximum of the implanted ions was then attempted via APT and EELS. We found that the chosen dose of 1´10 Ag ions cm -2 resulted in an Ag concentration too low to quantify by these methods, so that a qualitative detection had to be achieved via TOF SIMS. Both spatially resolved cross-sectional nano XRD and SPED measurements revealed an amorphization of the region from the surface to a depth of 650 nm deep, partially also due to electron beam damage, which has been shown to be detrimental for the Li-ion conductivity. Moreover, from the corresponding X-ray diffractograms a compressive stress of up to 700 MPa with its peak at a depth of 850 nm has been determined. Thereafter, the impact of the introduced stressed zone on the crack propagation has been evaluated. Cracks were induced in the material, mechanically via nanoindentation, and they indeed formed preferentially at the zone of compressive stress at 850 nm and parallel to the surface. Finally, it has been shown that electrochemically induced cracks (dendrites) can also be deflected, with the crack beginning to kink at around 700 nm depth and fully deflecting slightly after the stress maximum at 1.5 µm.