| 초록 |
Poly(ethylene oxide) (PEO)-lithium salt complex has been employed as the electrolytes of lithium batteries on account of its high electrochemical stability and ionic conductivity. However, anion diffusion causes concentration polarization during battery usage, limiting charge/discharge rates. This promoted the development of single-ion conductors with covalently attached anions in polymer chains. This enabled reaching cation transference number up to 0.95, but resulted in significant reduction in the ionic conductivity. Here, we report a new block copolymer composed of PEO and poly(dithiooxamide) (PDTOA). The high cation transport over 0.5 was achieved from PEO-b-PDTOA/lithium salt complex while maintaining high ionic conductivity ~ 1 mS/cm and normalized conductivity ~ 0.8. Mechanisms underlying the improvement were attributed to specific hydrogen bonding interactions between PDTOA and anion of lithium salt, as examined by combining thermal analysis, FT-IR, and ab initio calculation. |
