| Currently, the ionic conduction mechanism of polymer electrolytes exist two kinds of conduction mechanism, including the conduction in amorphous region and in crystalline and orderly region, respectively. The two mechanisms consider that the ionic conduction is closely related to the coordination and dissociation of coordination between polymer matrix and alkali metal salts. Heretofore, there are few specific reports about Ionic transport, coordination and the change of the number of ligands in the process of ionic transfer. Lacking of understanding of the real microscopic scale transport process of ions under dynamic conditions (i.e. external electric field). Actually, the microscopic kinetics of the transport of ions in the polymer electrolytes under an external electric field can not be truly demonstrated by X-ray diffraction, infrared spectrum, AC impedance spectroscopy, mass spectrometry and other traditional research methods, because of that traditional research methods are usually carried out without external electric field. Consequently, trying to elucidate the microscopic kinetic information of the real dynamic transport process of ions under an external electric field is a big challenging and very necessary research. It may play a guide role in understanding the micro conduction mechanism of polymer electrolytes and developing novel polymer electrolytes.In this study, the LiClO4 has been doped into PVA matrix. In addition, PVA-based SPE and GPE with different doping salt concentrations has been prepared. The ionic conductivity and electrochemical stability of corresponding SPE and GPE have been studied by AC impedance spectroscopy and linear sweep voltammetry, respectively. Simultaneously, We successfully evaluate the microscopic kinetic information of dynamic transport of ions under external electric fields by combing advanced time resolved infrared spectroscopy technology with two-dimensional infrared spectroscopy technology. The microscopic scale transport behaviors of ions in the SPEs have also been discussed in detail. The main conclusions are as follows:(1)The ionic conductivity of SPE and GPE with different doped concentrations will increase with the increment of temperature. In addition, the increase of the doped salt concentration will lead to the increment of the conductivity of corresponding SPEs or GPEs to some extent; The ionic conductivity of GPE is significantly higher than that of SPE under the same experimental conditions, which showing that the addition of plasticizer (PC) can effectively improve the ionic conductivity.(2) The interaction between lithium ion and polymer matrix has been confirmed by the generalized 2D correlation infrared spectra data. The transport behaviors of lithium ion in SPE and GPE under an external electric field occur in the time scale of microsecond, that is to say, the transport time scale is the order of magnitude of μs; In the order of magnitude of μs, the lithium ion is apt to move along the direction of the external electric field (i.e. potential gradient). However, this process is very complicated and shows periodic transport behavior, in which the coordinated ions will be abruptly dissociated and again coordinated so long as the external electric field is loaded.(3) PC-MW2D data show that the transport of lithium ion in both SPE and GPE under the external electric field appear periodical trends. In addition, both of them are accompanied by the interaction of dissociation and coordination. Among them, the time for the SPE dissociation of coordinated ion-pairs is about 1-8μs,and the time for the GPE dissociation of coordinated ion-pairs is around 1.5-8.5μs. Moreover, we obtain the coordination number in such SPEs (i.e. The molar ratio of hydroxyl to lithium cations OH/Li), and the ratio is about 2-5.(4) PC-MW2D data confirm that the coordination state of lithium ion and polymer chain in SPE and GPE will be accordingly changed with the concentration of lithium ion and the strength of the external electric field; Moreover, we also find that the more the number of the hydroxyl coordinated with lithium ions is, the shorter the time for the removal of one hydroxyl coordinated lithium ion will be.
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