Heterostructural Nanolattice Capacitors In article number 2208409, Julia R. Greer, Bong-Joong Kim, and co-workers demonstrate density-variant nanolattices that exhibit bi-phase deformation by which the lower-density region protects the higher-density region. This deformation improves the electrical breakdown strength by ≈3.3 fold of the uniform-density nanolattice, while maintaining the ultralow-k of ≈1.2 with complete electric and dielectric stability and recoverability during 100 cyclic compressions to 62.5% strain.