Synergistic Gelation of Silica Nanoparticles and a Sorbitol-Based Molecular Gelator to Yield Highly-Conductive Free-Standing Gel Electrolytes

Abstract

Lithium-ion batteries have emerged as the preferred type of rechargeable batteries, but there is a need to improve the performance of the electrolytes therein. Specifically, the challenge is to obtain electrolytes with the mechanical rigidity of solids but with liquid-like conductivities. In this study, we report a class of nanostructured gels that are able to offer this unique combination of properties. The gels are prepared by utilizing the synergistic interactions between a molecular gelator, 1,3:2,4-di-O-methyl-benzylidene-d-sorbitol (MDBS), and a nanoscale particulate material, fumed silica (FS). When MDBS and FS are combined in a liquid consisting of propylene carbonate with dissolved lithium perchlorate salt, the liquid electrolyte is converted into a free-standing gel due to the formation of a strong MDBS-FS network. The gels exhibit elastic shear moduli around 1000 kPa and yield stresses around 11 kPa-both values considerably exceed those obtainable by MDBS or FS alone in the same liquid. At the same time, the gel also exhibits electrochemical properties comparable to the parent liquid, including a high ionic conductivity (~5 × 10(-3) S/cm at room temperature) and a wide electrochemical stability window (up to 4.5 V).

1,3:2,4-Dibenzylidene-d-sorbitol (DBS) and its derivatives – efficient, versatile and industrially-relevant low-molecular-weight gelators with over 100 years of history and a bright future

“…107 It is worth noting that FS did not itself form a gel in the mentioned solvent, but helped rigidify the resulting organogel via non-covalent cross-linking between the silanol (Si-OH) groups of FS and the free hydroxyl groups of MDBS. 107 It is worth noting that FS did not itself form a gel in the mentioned solvent, but helped rigidify the resulting organogel via non-covalent cross-linking between the silanol (Si-OH) groups of FS and the free hydroxyl groups of MDBS.…”

Self-assembly of organogels via new luminol imide derivatives: diverse nanostructures and substituent chain effect

“…The self-assembly of small functional molecules into supramolecular structures is a powerful approach toward the development of new nanoscale materials and devices [1-7]. As a novel class of self-assembled materials, low weight molecular organic gelator (LMOG) gels organized in regular nanoarchitectures through specific noncovalent interactions including hydrogen bonds, hydrophobic interaction, π-π interactions, and van der Waals forces have recently received considerable attention [8-13].…”

A flexible solid-state supercapacitor based on a poly(aryl ether ketone)–poly(ethylene glycol) copolymer solid polymer electrolyte for high temperature applications

“…3. Obviously, the ionic conductivities of all the polymer electrolytes rise quickly with increasing temperature, 43,44 and the plots of the ionic conductivity are non-linear, it was confirmed that their conductivities follow the Vogel-Tamman-Fulcher (VTF) equation. [45][46][47] This non-linear VTF behavior is mainly attributed to the complexing segments of the amorphous PEG chain with Li ions, which assisted ions transport through the polymer electrolyte membrane rather than the pores of polymer electrolyte membrane, also, this phenomenon can also be seen in Fig.2 (d)-(e).…”