Ion Exchange Induced Efficient N-Type Thermoelectrics in Solid-State

摘要

High-performance n-type solid-state ionic thermoelectrics (SS i-TEs) for lowgradeheat harvesting are highly desired and challenging. Here, the designand synthesis of an efficient n-type mixed conductor via ion pair modulationis demonstrated, which consists of biguanide hydrochloride (MfmCl)and a poly(3,4-ethylenedioxythiophene) (PEDOT): poly(styrenesulfonate)(PSS) polymeric complex in a solid film. Theoretical calculations and nano/microstructure characterization reveal that the binding preference of ion pairsoffers energetically favorable ion exchange in the matrix, which induces notonly tightly bound Mfm PSS species but also favorable anion diffusion channels.Consequently, an enhanced ionic conductivity of 1.40 S m?1 with a recordhighest negative thermopower of ?46.97 mV K?1 is achieved for the n-typemixed conductor thus far.