Nanocomposite Ionogel Electrolytes for Solid‐State Rechargeable Batteries

Ionogels composed of ionic liquids and gelling solid matrices offer several advantages as solid‐state electrolytes for rechargeable batteries, including safety under diverse operating conditions, favorable electrochemical and thermal properties, and wide processing compatibility. Among gelling solid matrices, nanoscale materials have shown particular promise due to their ability to concurrently enhance ionogel mechanical properties, thermal stability, ionic conductivity, and electrochemical stability. These beneficial attributes suggest that ionogel electrolytes are not only of interest for incumbent lithium‐ion batteries but also for next‐generation rechargeable battery technologies. Herein, recent advances in nanocomposite ionogel electrolytes are discussed to highlight their advantages as solid‐state electrolytes for rechargeable batteries. By exploring a range of different nanoscale gelling solid matrices, relationships between nanoscale material structure and ionogel properties are developed. Furthermore, key research challenges are delineated to help guide and accelerate the incorporation of nanocomposite ionogel electrolytes in high‐performance solid‐state rechargeable batteries.     

Ionogel Electrolytes for High‐Performance Lithium Batteries: A Review

Ionic liquids (ILs) are important electrolytes for applications in electrochemical devices. An emerging trend in ILs research is their hybridization with solid matrices, named ionogels. These ionogels can not only overcome the fluidity of ILs but also exhibit high mechanical strength of the solid matrix. Therefore, they show promise for applications in building lithium batteries. In this review, various types of solid matrices for confining ILs are summarized, including nonmetallic oxides, metal oxides, IL‐tethered nanoparticles, functionalized SiO₂, metal–organic frameworks, and other structural materials. The synthetic strategies for ionogels are first documented, focusing on physical confinement and covalent grafting. Then, the structure, ionic conductivity, thermal stability, and electrochemical stability of ionogels are addressed in detail. Furthermore, the authors highlight the potential applications of state‐of‐art ionogels in lithium batteries. The authors conclude this review by outlining the remaining challenges as well as personal perspectives on this hot area of research.     

Electrolytes and plasma expanders

Summary The effect of Gey's balanced salt solution deficient in NaCl on cells in tissue culture led to a study of various solutions employed as vehicles for plasma expanders.The behavior of epithelium from the adult human mucosa, tonsils from children, and mouse kidney papilla was recorded in a perfusion chamber with phase contrast, time-lapse cinematography. After perfusion for one to two hours with fluid nutrient medium, test solutions were brought in contact with the cells for one hour. The fluid system was then generally replaced with Gey's balanced salt solution and, or, the proteinaceous nutrient medium.So-called normal saline produced marked injury both when employed alone or in combination with 6% Dextran. Damage resulting from 5% dextrose either alone or in combination with 6% Dextran was characterized by vacuole formation. Dextran at 6% in Gey's balanced salt solution or in Ringer's solution appeared to produce little injury to cells under the conditions of these experiments.Work in progress is designed to examine the lifesaving value of the various solutions in the treatment of partially exsanguinated dogs.This investigation was supported by the Medical Research and Development Board, Office of the Surgeon General, Department of the Army, under Contract No. DA-49-007-MD-32.     

The Electrical Conductance of Semipermeable Membranes: III. Bipolar Flow-Symmetric Electrolytes

The first paper of this series presented a general formulation of the problem of stationary ion flow through membranes. The second treated in detail the special case of unipolar flow across membranes separating symmetric electrolytes. In this, the third paper of the series, we deal with another special case, that of bipolar flow between symmetric electrolytes. Here it is assumed that the total current is carried by both positive and negative permeant ions. The restriction to symmetric electrolytes implies that all ions present in the membrane and surrounding solutions have valences of identical absolute magnitude. After extracting from the general development a set of equations appropriate to the special case being considered, we outline a procedure for the numerical solution of the conductance problem for this case. Numerical results, presented as part of a discussion of approximate analytic methods of solution, establish the utility of these methods. A discussion of the significance of this work for membrane studies is presented in conclusion.     

CdS/Graphene Nanocomposite Photocatalysts

Heterogeneous photocatalysis using semiconductors and renewable solar energy has been regarded as one of the most promising processes to alleviate, and even solve, both the world crises of energy supply and environmental pollution. In the past few years, many encouraging achievements have been made in the research area of graphene‐based semiconductor photocatalysts. Among them, CdS/graphene nanocomposites have attracted extensive attention as an important kind of photocatalyst in chemical and material science, due to its superior photocatalytic activity and photostability under visible‐light irradiation. The aim here is to address the enhancement mechanism of the photocatalytic performance of CdS/graphene composite photocatalysts, and systematically summarize recent progress regarding the design and synthesis of CdS/graphene nanocomposites. These nanocomposites are promising for a great diversity of applications in visible‐light photocatalytic fields, including artificial photosynthetic systems (photocatalytic hydrogen production and CO₂ reduction), environmental remediation, and organic photosynthesis. Special attention is given to the photocatalytic hydrogen production and pollutant photodegradation over CdS/graphene nanocomposite photocatalysts. Furthermore, perspectives on CdS/graphene‐based materials are discussed, including the various remaining challenges for large‐scale applications, identifying prospective areas for related research in this field.     

Highly Tough,Li‐Metal Compatible Organic–Inorganic Double‐Network Solvate Ionogel

Ionogels are considered promising electrolytes for safe lithium‐ion batteries (LIBs) because of their low flammability, good thermal stability, and wide electrochemical stability window. Conventional ionic liquid‐based ionogels, however, face two main challenges; poor mechanical property and low Li‐ion transfer number. In this work, a novel solvate ionogel electrolyte (SIGE) based on an organic–inorganic double network (DN) is designed and fabricated through nonhydrolytic sol–gel reaction and in situ polymerization processes. The unprecedented SIGE possesses high toughness (bearing the deformation under the pressure of 80 MPa without damage), high Li‐ion transfer number of 0.43, and excellent Li‐metal compatibility. As expected, the LiFePO₄/Li cell using the newly developed SIGE delivers a high capacity retention of 95.2% over 500 cycles, and the average Coulombic efficiency is as high as 99.8%. Moreover, the Ni‐rich LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811)/Li cell based on the modified SIGE achieves a high Coulombic efficiency of 99.4%, which outperforms previous solid/quasi‐solid‐state NCM811‐based LIBs. Interestingly, the SIGE‐based pouch cells are workable under extreme conditions (e.g., severely deforming or clipping into segments). In terms of those unusual features, the as‐obtained SIGE holds great promise for next‐generation flexible and safe energy‐storage devices.