High-Power Bipolar Solid-State Batteries Enabled by In-Situ-Formed Ionogels for Vehicle Applications

Employing solid electrolytes (SEs) for lithium-ion batteries can boost the battery tolerance under abusive conditions and enable the implementation of bipolar cell stacking, leading to higher cell energy and power density as well as simplified thermal management. In this context, a bipolar solid-state battery (SSB) has received ever-increasing attention in recent years. However, poor solid-solid interfacial contact within the bipolar SSB deteriorates the battery power capability, representing a technical challenge for vehicle applications. In this work, a bipolar SSB pouch cell with two cell units connected in series is demonstrated without any short circuit or current leakage. With the assistance of an in-situ-formed nonflammable ionogel at particle-to-particle interfaces, the constructed bipolar cell manifests superior power capability and can meet the engineering cold crank requirements in 0, -10, and -18 °C environments. Furthermore, the excellent tolerance of the ionogel-introduced bipolar SSB under abusive conditions was proved by folding, cutting, and burning the cells. The above salient features suggested that the developed strategy herein holds promise to advance the next-generation high-performance SSBs.

Thermally reversible solidification of novel ionic liquid [im]HSO4 by self-nucleated rapid crystallization: investigations of ionic conductivity, thermal properties, and catalytic activity

A new, multifunctional [im]HSO₄ ionic liquid: a thermally reversible solid-state electrolyte and an efficient catalyst for acid-catalyzed chemical processes.

Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl)-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl)-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl) imide) (LiNTf₂), the resulting 1-(2-hydroxyethyl)-3-methylimidazolium NTf₂ was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN) to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by ¹H-, ¹³C-, ¹¹B- and ¹⁹F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10⁻⁴–1.6 × 10⁻⁵ S cm⁻¹ at 51 °C. This was higher than other organoboron molten salts ever reported.

Lithium ion conductive behavior of TiO2 nanotube/ionic liquid matrices

A series of TiO2 nanotube (TNT)/ionic liquid matrices were prepared, and their lithium ion conductive properties were studied. SEM images implied that ionic liquid was dispersed on the whole surface of TNT. Addition of TNT to ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (BMImTFSA)) resulted in significant increase of ionic conductivity. Furthermore, lithium transference number was also largely enhanced due to the interaction of anion with TNT. Vogel-Fulcher-Tammann parameter showed higher carrier ion number for TNT/BMImTFSA in comparison with BMImTFSA.

Ionic liquids and cellulose: dissolution, chemical modification and preparation of new cellulosic materials

Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.