Fast lithium-ion transportation is found in the crystalline polymer electrolytes, a-CD-PEO n /Li + (n = 12, 40), prepared by selfassembly of a-cyclodextrin (CD), polyethylene oxide (PEO) and Li + salts. Ad etailed solid-state NMR study combinedw ith the X-ray diffraction technique reveals the uniques tructural features of the samples, that is, a) the tunnels tructure formedb y the assembled CDs, providing the ordered long-range pathway for Li + ion transportation;b )the all-trans conformational sequenceo ft he PEO chains in the tunnels, attenuating significantly the coordination between Li + and the EO segments. The origin of the fast lithium-ion transportation has been attributed to these unique structural features. This work demonstrates the first example in solid polymer electrolytes (SPEs) for "creating" fast iont ransportation through material design and will find potentiala pplicationsi nt he design of new ionconducting SPE materials.Fast lithium-ion transportation is widely presenti nt he ceramic lithium superionic conductors, [1] and its molecular origin is attributed to the unique structural features, which "create" the highly mobile lithium ions and providet he special ion pathway to facilitate the long distance transportation of lithium ions.[2]The reported lithium superionic conductors often exhibit a very high ionic conductivity at the ordinary temperature. [3] However,t he similar fast lithium-ion transportation has never been found in solid polymer electrolytes (SPEs). Ther eported best-in-class solid polymer electrolytes now can have the conductivity of 10 À4 Scm, [4a] which is still 2-3 order lower than the inorganic superionic conductors. The reasons are at least twofold:1 .T he strong coordinationb etween Li + ions and the polymer segments that often significantly lowerst he mobility of Li + ions;2.The lack of long-rangeordered pathway that suppresses the efficient long-range Li + ion transportation. Many efforts to enhancet he ionic conductivity of SPE have been made in am anner to solvet he above two issues.F or example,t he isovalent doping, which can lower the coordination between Li + ions and the polymer segments and thus increase the Li + mobility,h as been regarded as an effective strategy to facilitatet he Li + transportation.[4] Exploiting the high segmental mobility of oligomeric polyethylene oxide (PEO) to attenuate the coordination between Li + ions and the polymer segmentsa nd in turn increaset he conductivity also falls into this category.[5] Along the line of constructing the ordered structures for the long-range ion transportation, some pioneer works have studied the conductive polyethylene oxide (PEO):Li + complex crystals where PEO chainsa dopt the helical structures to form visual tunnels to facilitate the long-range transportation of the Li + ions.[6] Later,aseries of interesting works on theo riented PEO:Li + complex crystals concretely evidence the influences of long-range ordered structure on the ionic conductivity of material. [7] Recently,w er eported ac rystall...

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 13C 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 ∼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.