Enhancing the Performance of Ceramic-Rich Polymer Composite Electrolytes Using Polymer Grafted LLZO

Abstract

Solid-state batteries are the holy grail for the next generation of automotive batteries. The development of solid-state batteries requires efficient electrolytes to improve the performance of the cells in terms of ionic conductivity, electrochemical stability, interfacial compatibility, and so on. These requirements call for the combined properties of ceramic and polymer electrolytes, making ceramic-rich polymer electrolytes a promising solution to be developed. Aligned with this aim, we have shown a surface modification of Ga substituted Li7La3Zr2O12 (LLZO), to be an essential strategy for the preparation of ceramic-rich electrolytes. Ceramic-rich polymer membranes with surface-modified LLZO show marked improvements in the performance, in terms of electrolyte physical and electrochemical properties, as well as coulombic efficiency, interfacial compatibility, and cyclability of solid-state cells.

Transport Properties and Local Ions Dynamics in LATP‐Based Hybrid Solid Electrolytes

“…Figure 6. Self-diffusion coefficients and transference numbers by PFG-NMR: diffusion coefficients of a) 7 Li and b) 19 F from 20 to 80 °C; c) comparison of the diffusion coefficients at 60 °C; d) ionic conductivity calculated from the diffusion coefficients with the Nernst-Einstein equation; e) Haven ratios between 30 and 70 °C; f) lithium transference numbers, calculated from the diffusion coefficients of 7 Li and 19 F, between 20 and 70 °C. The red asterisk indicates the transference number calculated by potentiostatic polarization method.…”

“…Information on the individual mobility of anions and cations was obtained by PFG-NMR. The self-diffusion coefficients of 7 Li (D Li ) and 19 F (D F ) between 20 and 80 °C are depicted in Figure 6a,b, respectively. Both diffusion coefficients increase with temperature between 10 −12 to 10 −11 m 2 s −1 , but the values of D F are generally higher than those of D Li , as could be expected for polymer electrolytes, since ethylene oxide units strongly coordinate with Li + cations.…”

“…For instance, possible chemical interactions of the anions with the particles surface may give rise to a decrease of the anion's mobility, prompting an increase of the cation transference number and of the oxidative stability in HSEs. [29] To study the possible TFSI − aggregation at the LATP surface, 19 F NMR experiments were conducted and T 1 relaxation times were investigated. The longitudinal relaxation times of the nuclear magnetizations in NMR depend strongly on the local mobilities and time fluctuations of the chemical environments.…”

“…Solid-state nuclear magnetic resonance (NMR) is a powerful tool for the investigation of ions' diffusivity and chemical interactions, and has been recently used in the study of the conduction mechanism of HSEs. [14,19,20,[44][45][46][47] All these aspects, long-range charge and mass transport properties, and local chemical interactions, need to be understood to fully reveal the conduction mechanism in HSEs, and to assess the real contribution of Li + -conducting fillers in HSEs.…”

Hybrid Particle Brush Coatings with Tailored Design for Enhanced Dendrite Prevention and Cycle Life in Lithium Metal Batteries

“…This comprises polymer chains covalently attached, or grafted, onto/from nanoparticles. These “particle brushes” have been studied previously in the battery literature with a variety of polymer chemistries. − In one approach, 5 kg mol –1 poly­(ethylene oxide) (PEO) was functionalized with a silane group and condensed onto silica nanoparticles. , Plasticized with lithium bis­(trifluoromethylsulfonyl)­imide (LiTFSI) salt, it improved capacity retention of lithium metal cells cycled at 0.2 mA cm –2 . As for mechanics, it was found that interparticle interactions resulted in caging, where friction between particles has a yielding effect per applied stress. , Interparticle interactions were found to be tunable by adjustment of the architecture of the particle brushes.…”