In this work, we demonstrate that a deliberately designed annealing process can induce formation of defects in polyether/Li+ complex crystals. The Li+ concentration diffusion in the complex crystals and the amorphous structures is considered to play a critical role in the formation of crystal defects. The C-13 2D exchange NMR shows that the annealing-induced crystal defects can greatly enhance the segmental mobility in the polyether/Li+ complex crystals. The rate of helical jump motions in the deliberately annealed polyether/Li+ complex crystals is similar to 100 times higher than those reported in the literature. This work deepens our understanding of the defect formation in polyether/Li+ complex crystals and has important implications on the ionic conduction enhancement of polyether-based crystalline polymer electrolytes.