An electrochemical cell includes a negative electrode that contains lithium and an electrolyte system. In one variation, the electrolyte system includes a first liquid electrolyte, a solid-dendrite-blocking layer, and an interface layer. The solid dendrite-blocking layer is ionically conducting and electrically insulating. The dendrite-blocking layer includes a first component and a distinct second component. The dendrite-blocking layer has a shear modulus of greater than or equal to about 7.5 GPa at 23° C. The interface layer is configured to interface with a negative electrode including lithium metal on a first side and the dendrite blocking layer on a second opposite side. The interface layer includes a second liquid electrolyte, a gel polymer electrolyte, or a solid-state electrolyte. The dendrite-blocking layer is disposed between the first liquid electrolyte and the interface layer.