No abstract

Graphene oxide film is made of stacked graphene layers with chemical functionalities, and we report that plasticity in the film can be engineered by strain rate tuning. The deformation behavior and plasticity of such functionalized layered systems is dominated by shear slip between individual layers and interaction between functional groups. Stress-strain behavior and theoretical models suggest that the deformation is strongly strain rate dependent and undergoes brittle to ductile transition with decreasing strain rate.

Solid‐electrolytes (SEs) can provide a pathway to increase energy‐density in lithium metal batteries. However, lithium metal penetration through garnet based LLZO solid electrolytes has been identified as a critical failure process. This phenomenon is related to chemo‐mechanical processes which are difficult to probe. In particular, characterizing the dynamic mechanical deformations that occur in electrode‐SE structures is very challenging. This study reports in situ curvature measurements that are thus designed to probe chemo‐mechanical phenomena that occur during lithium plating. The novel experimental cell configuration created for this work shows that pressure builds up in the Li metal during plating, up until the point where short circuits occur. The resulting data are analyzed with a detailed finite element model (FEM) to quantitatively evaluate stress evolution. The results show that Li metal plating within a surface flaw can produce stress build‐up prior to short‐circuiting. The combined results from both the experiments and the FEM suggest that it is critical to minimize surface defects and flaws during the manufacturing processes.