A composite electrolyte based on a garnet electrolyte (LLZO) and polyester-based co-polymer (80:20 ε-caprolactone (CL)-trimethylene carbonate, PCL-PTMC with LiTFSI salt) is prepared. Integrating the merits of both ceramic and co-polymer electrolytes is expected to address the poor ionic conductivity and high interfacial resistance in solid-state lithium-ion batteries. The composite electrolyte with 80 wt % LLZO and 20 wt % polymer (PCL-PTMC and lithium bis­(trifluoromethanesulfonyl)­imide (LiTFSI) at 72:28 wt %) exhibited a Li-ion conductivity of 1.31 × 10–4 S/cm and a transference number (t Li+ ) of 0.84 at 60 °C, notably higher than those of the pristine PCL-PTMC electrolyte. The prepared composite electrolyte also exhibited an electrochemical stability of up to 5.4 V vs Li+/Li. The interface between the composite electrolyte and a LiFePO4 (LFP) cathode was also improved by direct incorporation of the polymer electrolyte as a binder in the cathode coating. A Li/composite electrolyte/LFP solid-state cell provided a discharge capacity of ca. 140 mAh/g and suitable cycling stability at 55 °C after 40 cycles. This study clearly suggests that this type of amorphous polyester-based polymers can be applied in polymer-in-ceramic composite electrolytes for the realization of advanced all-solid-state lithium-ion batteries.

No abstract

Herein we propose a simple, volatile organic solvent (VOC)-free tricomponent reaction platform for the stoichiometric step-growth polymerization between diepoxy resins and dicarboxylic acid in an imidazolium IL medium. The established...

A new method for poly (3, 4-ethylenedioxythiophene) (PEDOT) synthesis based on acid-assisted polymerization is proposed, and the optical and structural properties of the obtained material are explored. Special attention is given to the effect of the polar Bronsted acid on the formation of oligomer/polymer chains and their ability to assemble into nanoobjects. By using 1H and 13C NMR spectroscopy (in the liquid and solid state), the formation of PEDOT in a neutral state was proven. Matrix-assisted laser desorption/ionization–time-of-flight, static light scattering, and dynamic light scattering spectroscopies were used to determine the M w and size of PEDOT nanoobjects. Moreover, we used density functional theory calculations to seek a correlation between the length of the PEDOT oligomer chain and the position of its lowest-energy absorption peak S1. All calculations were performed in concentrated formic acid and compared with calculations in the gas phase. In addition, we demonstrate a correlation between the photoluminescence (PL) from individual PEDOT chains and that from PEDOT chains assembled into nanoobjects. While individual PEDOT chains show four PL peaks, the assembled PEDOT nanoobjects show only one PL peak. Tuning the process of self-assembly for individual PEDOT chains is a promising way to control the properties of a polymer material.