Polyether-Based Supramolecular Electrolytes With Two-Dimensional Boroxine Skeleton

Abstract

Solid polymer electrolytes mainly based on polyethers have been actively investigated for over 40 years to develop safe, light, and flexible rechargeable batteries. Here, we report novel supramolecular electrolytes (SMEs) composed of polyether derivatives and a two-dimensional boroxine skeleton synthesized by the dehydration condensation of 1,4-benzenediboronic acid in the presence of a polyether with amines on both chain ends. The formation of SMEs based on polyether derivatives and boroxine skeleton was confirmed by Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were performed to evaluate the electrochemical stability and lithium conductive properties of SMEs with given amounts of lithium bis(trifluoromethylsulfonyl)amide (LiTFSA). The ionic conductivity of SME/LiTFSA composites increased with increasing lithium-salt concentration and reached a maximum value at a higher concentration than those of simple polyether systems. The lithium-ion transference number (tLi+) of SME/LiTFSA was higher than those of polyether electrolytes. This tendency is unusual for a polyether matrix. SME/LiTFSA composite electrolytes exhibited a stable lithium plating/striping process even after 100 cycles. The current density increased with an increasing number of cycles. The combination of ion conductive polymers and a two-dimensional boroxine skeleton will be an interesting concept for developing solid electrolytes with good electrochemical properties.

Robust Dynamic Epoxy Adhesives with High Environmental Tolerance Enabled by the Coordination of Small-Molecule Coupling Agents with Boroxine

“…The out-of-plane bending vibration peak at 705 cm –1 corresponds to displacements of boron atoms syn to the displacements of aryl hydrogen atoms. The out-of-plane bending vibration peak at 748 cm –1 corresponds to boron displacements that are anti to the displacements of aryl hydrogen atoms. , Some scholars have also demonstrated through density functional theory that nitrogen coordination may cause changes in the configuration of boroxines. , With the increased addition of APTES, the peak at 748 cm –1 gradually increases, the peak at 705 cm –1 gradually decreases, and a new peak gradually appears at 696 cm –1 . It proved that with the increase of APTES, the introduction of nitrogen coordination can change the configuration of boroxines, thus stabilizing boroxines and improving their hydrolysis stability.…”

“…The out-of-plane bending vibration peak at 748 cm −1 corresponds to boron displacements that are anti to the displacements of aryl hydrogen atoms. 24,25 Some scholars have also demonstrated through density functional theory that nitrogen coordination may cause changes in the configuration of boroxines. 26,27 With the increased addition of APTES, the peak at 748 cm −1 gradually increases, the peak at 705 cm −1 gradually decreases, and a new peak gradually appears at 696 cm −1 .…”