Organic ionic plastic crystals: flexible solid electrolytes for lithium secondary batteries

Abstract

The growing global demand for energy has led to the active development of efficient energy generation and storage technologies, driving the development of electrochemical devices such as high-energy density rechargeable...

Ionic plastic crystals and ionic liquids containing quaternary cations with alkenyl substituents: chemical phase transformations by bromine vapor

“…The melting entropies of plastic crystals are typically less than 21 J mol −1 K −1 . 4 Extensive studies on IPCs have been conducted on their solid-state properties such as ionic conductivity, 5–8 ferroelectricity, 9–16 magnetism, 17–19 and thermal energy storage. 20,21 In addition to quaternary salts, salts containing inorganic ions 22 and organometallic cations 23–27 also exhibit the IPC phase.…”

“…20,21 In addition to quaternary salts, salts containing inorganic ions 22 and organometallic cations 23–27 also exhibit the IPC phase. Physical doping of various ions 5–8,28–32 has typically been used to control physical properties and phase behaviors of IPCs, but approaches via chemical reactions remain unexplored.…”

Boosting the Ionic Conductivity of Pyrrolidinium-Based Ionic Plastic Crystals by LLZO Fillers

“…In addition to plasticity, the OIPCs of interest for battery application have many other favorable properties for safety and efficiency: low flammability, negligible volatility, and relatively high ionic conductivity for a solid. Some OIPCs are being studied as materials for solid electrolytes. − The thermal and electrochemical properties of OIPCs are very different depending on the type of cation and anion of which they are comprised . Some of the previous works − have shown that N , N -diethylpyrrolidinium bis­(fluorosulfonyl)­amide, or [C 2 epyr]­[FSA] (see Figure ), has suitable properties for a solid electrolyte: high thermal stability (a decomposition temperature of 300 °C) and the highest ionic conductivity (9.6 × 10 –6 S cm –1 at 25 °C) ever observed for OIPCs.…”

Tailoring Silicon Composite Anodes with Li+-Containing Organic Ionic Plastic Crystals for Solid-State Batteries

“…32,33 However, such approaches have not been actively studied, which is, in part, due to the lower ionic conductivity of soft solid electrolytes, e.g., lithium bis(fluorosulfonyl)imide (LiFSI)-containing polyethylene oxide (PEO) (5.9 × 10 -7 S cm -1 at 30 °C, molar ratio of ethylene oxide, EO to Li + = 20) 34 compared to sulfide-based solid electrolytes, e.g., 70Li 2 S•30P 2 S 5 (LPS) (2.7 × 10 -3 S cm -1 at 25 °C). 35 Organic ionic plastic crystals (OIPCs), which can be categorized as soft solid electrolytes, have gained researchers' attention in recent years 36,37 because of their advantageous features such as high electrochemical and thermal stability, the unique ion-conduction behavior dependent on the complex interplay in the medium (e.g., the grain size of OIPC electrolytes, which is related to the volume of a grain-boundary phase; 38,39 concentration of metal salts; [40][41][42][43] and physicochemical property of insoluble dopants), 44,45 and negligible volatility. Since the discovery of the conductivity improvements by the addition of lithium salts to OIPCs, 46 they have been mainly studied as solid electrolyte membranes between two electrodes.…”

“…This is because such OIPC-containing electrodes can create new ion-conduction pathways inside the electrodes, thereby facilitating electrode reactions involving target ions even though non-electron-and non-ion-conductive voids still remain. 49 The preparation of OIPC-containing electrodes is a new process that has started to be developed in recent years 37,[49][50][51][52][53][54] and, therefore, the systematic understanding of the effect of preparation methods on the resulting electrode structures and battery performance of the OIPC-containing electrodes will provide insights into the realization of SSBs with high energy density and cost-effective production.…”