锂离子电池电解质盐双草酸硼酸锂的研究进展

介绍了双草酸硼酸锂(LiBOB)的基本性质,综述了LiBOB合成方法和应用情况,并对LiBOB与石墨负极匹配、高温稳定性、在溶剂中的溶解性、电导率和安全性等问题进行了论述,对研究方向也进行了简单的阐述。     

Ionic conductivity of Ln4Zr3O12 solid electrolytes synthesized by mechanochemistry

To explore their possible application as solid electrolytes in Solid Oxide Fuel Cells (SOFC), this contribution presents the synthesis, characterization and electrical properties of Ln₄Zr₃O₁₂ (Ln = Y, Ho, Er and Yb) zirconates. All samples were obtained by mechanical milling and their electrical properties were analyzed as a function of frequency and temperature, by using impedance spectroscopy. Our results show that defective fluorite-type zirconates might be successfully obtained after milling stoichiometric mixtures of the corresponding oxides, for 30–40 h in a planetary mill. Such structural form persists even after firing the as-prepared Y, Ho and Er zirconates, at very high temperatures (1500 °C); whereas, Yb₄Zr₃O₁₂ shows a transition to a rhombohedral δ-phase on firing. Ionic conductivity (σ) values obtained for all compositions at 700 °C (including fluorites and δ-phase), are comparable to those reported for similar ionic conductors, and within the 10^−3.82 to 10^−6.13 S cm⁻¹ range. Higher σ values were obtained for those zirconates preserving the disordered fluorite-type structure after firing.     

1,2-Dimethylimidazole based bromine complexing agents for vanadium bromine redox flow batteries

To stabilize bromine produced during a vanadium-bromine redox flow batteries (VBr RFBs) charging, a bromine complexing agent (BCA) should be effectively used as a supporting material in VBr electrolyte. However, there remains a problem of improving the unstable reversibility between V²⁺ and V³⁺ in electrolyte including halogen elements (Br and Cl). This paper describes two imidazole-based BCAs, which are 1,2-dimethyl-3-ethylimidazolium bromide (DMEIm: C₇H₁₃BrN₂) and 1,2-dimethyl-3-propylimidazolium bromide (DMPIm: C₈H₁₅BrN₂), for not only confirming the capture of bromine but also improving the redox reaction of vanadium ions in VBr electrolyte. The effectiveness of the proposed two imidazole-based BCAs is demonstrated through the following experiments: cyclic voltammetry (CV), nuclear magnetic resonance analysis (NMR), scanning electron microscopy (SEM) analysis and cyclic cell operation test. Experimental results show that both the diffusion coefficient and the peak currents of each electrolyte using the proposed imidazole-based BCAs increases linearly with the rise of scan rate on the recorded CV curves, providing improved reversible reaction of V²⁺/V³⁺ in negative electrolyte. It also exhibits that the electrolytes using the DMEIm and DMPIm provide significantly improved charge (discharge) capacities which are 9.38 (31.01) % and 11.8 (35.66) % higher than the pristine one, respectively, resulting in 13.27% and 14.36% higher current efficiencies. In addition, corrosion cracks on the separator surface due to bromine attack are not observed after the cyclic cell operation. Consequently, these results indicate that the proposed two imidazole-based BCAs can not only sequester bromine during the VBr RFB charging, but also enhance electrochemical reversibility caused by improving diffusion coefficient of vanadium.     

Development of the all‐vanadium redox flow battery for energy storage: a review of technological,financial and policy aspects

The commercial development and current economic incentives associated with energy storage using redox flow batteries (RFBs) are summarised. The analysis is focused on the all‐vanadium system, which is the most studied and widely commercialised RFB. The recent expiry of key patents relating to the electrochemistry of this battery has contributed to significant levels of commercialisation in, for example, Austria, China and Thailand, as well as pilot‐scale developments in many countries. The potential benefits of increasing battery‐based energy storage for electricity grid load levelling and MW‐scale wind/solar photovoltaic‐based power generation are now being realised at an increasing level. Commercial systems are being applied to distributed systems utilising kW‐scale renewable energy flows. Factors limiting the uptake of all‐vanadium (and other) redox flow batteries include a comparatively high overall internal costs of $217 kW^?1 h^?1 and the high cost of stored electricity of ≈ The commercial development and current economic incentives associated with energy storage using redox flow batteries (RFBs) are summarised. The analysis is focused on the all‐vanadium system, which is the most studied and widely commercialised RFB. The recent expiry of key patents relating to the electrochemistry of this battery has contributed to significant levels of commercialisation in, for example, Austria, China and Thailand, as well as pilot‐scale developments in many countries. The potential benefits of increasing battery‐based energy storage for electricity grid load levelling and MW‐scale wind/solar photovoltaic‐based power generation are now being realised at an increasing level. Commercial systems are being applied to distributed systems utilising kW‐scale renewable energy flows. Factors limiting the uptake of all‐vanadium (and other) redox flow batteries include a comparatively high overall internal costs of $217 kW^?1 h^?1 and the high cost of stored electricity of ≈ $0.10 kW^?1 h^?1. There is also a low‐level utility scale acceptance of energy storage solutions and a general lack of battery‐specific policy‐led incentives, even though the environmental impact of RFBs coupled to renewable energy sources is favourable, especially in comparison to natural gas‐ and diesel‐fuelled spinning reserves. Together with the technological and policy aspects associated with flow batteries, recent attempts to model redox flow batteries are considered. The issues that have been addressed using modelling together with the current and future requirements of modelling are outlined. Copyright © 2011 John Wiley & Sons, Ltd.     

Photoinitiated polymerization in ionic liquids and its application

Ionic liquids (ILs) are low‐melting organic salts often liquid at room temperature, whose unique properties are the reason of increasing interest for their applications as solvents, reaction media and functional additives. The exceptional properties of ILs have proved to be particularly useful in polymer science giving the potential to produce polymeric materials with improved properties or to immobilize ILs in polymer matrices while keeping their special characteristics. One of the possibilities is polymerization in ILs which can also affect positively polymerization reactions. An especially attractive technique is photopolymerization due to the ease of process control, short reaction time and ambient working temperature. This review gives a literature survey of developments in photopolymerization processes carried out in ILs as well as applications of these processes. It covers both the photopolymerization in ILs as well as photopolymerization of IL monomers. The first part presents a short overview of physicochemical and photochemical properties of ILs; it includes also photochemical reactions and photoinitiation of polymerization in ILs. The second part covers both the basic research (kinetics of photopolymerization including polymerization rate coefficients and polymerization of IL monomers) as well as applications of UV‐induced polymerization in ILs. © 2016 Society of Chemical Industry     

Single-ion-conducting nanocomposite polymer electrolytes based on PEG400 and anionic nanoparticles: Part 2. Electrical characterization

Molecular relaxation and polarization phenomena of twelve single-ion-conducting nanocomposite polymer electrolytes (nCPEs) are studied using Broadband Electrical Spectroscopy (BES). The electrolytes are obtained by combining PEG400 oligomers with increasing amounts of anionic nanofiller comprised of fluorinated-TiO₂ associated with Li⁺ cations (LiFT^®), resulting in [PEG400/(LiFT)_y] systems with 0 ≤ y ≤ 26.4. This new class of [PEG400/(LiFT)_y] electrolytes allows us to achieve a significant single-ion conductivity (1.1·10⁻⁵ S cm⁻¹ at 30 °C for n_Li/n_O = 0.113) without the addition of lithium salts. To the best of our knowledge, this is the highest conductivity value reported for this class of electrolytes. This study, in conjunction with the results reported in Part 1, leads us to hypothesize a conduction mechanism in terms of two types of long-range charge-transfer processes. The first charge-transfer occurs at the interface between the filler nanoparticles and filler-PEG domains, while the second occurs through the PEG400 matrix with the assistance of polymer segmental motion. The measured Li⁺ transference numbers confirm that the studied materials are single-ion conductors.     

COSMO-RS-PDHS: A new predictive model for aqueous electrolytes solutions

This work introduces a new tool able to predict water activities and activity coefficients of electrolytes in binary {water–electrolyte} systems. In mixtures containing electrolytes, the system is characterized by the presence of both molecular and ionic species, resulting in three different types of interactions: ion–ion, molecule–molecule and ion–molecule.Ion–ion interactions are governed by electrostatic forces between ions that have a much longer range than other intermolecular forces. The long range interactions between ions are taken in account by the Pitzer term based on the Debye–Hückel theory.Molecule–molecule and ion–molecule interaction forces are known to be short-range in nature. To determine short range mean activity coefficients of salts in {water–electrolyte} binary mixtures, a chemical treatment of ions solvation is combined with the predictive power of the COSMO-RS model. The main originality of this work resides in this chemical treatment model that provides the thermodynamic relations which enable to determine the equilibrium properties of the real solution {water–salt}, knowing those of a hypothetical mixture containing water and hydrated clusters.The resulting model called “COSMO-RS-PDHS” predicts results that are in good agreement with experimental data.     

2D Enzyme Cascade Network with Efficient Substrate Channeling by Swinging Arms

In living cells, compartmentalized or membrane‐associated enzymes are often assembled into large networks to cooperatively catalyze cascade reaction pathways essential for cellular metabolism. Here, we report the assembly of an artificial 2D enzyme network of two cascade enzymes—glucose‐6‐phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH)—on a wireframe DNA origami template. Swinging arms were used to facilitate the transport of the redox intermediate of NAD⁺/NADH between enzyme pairs on the array. The assemblies of 2D enzyme networks were characterized by gel electrophoresis and visualized by atomic force microscopy (AFM). The spatial arrangements of multiple enzyme pairs were optimized to facilitate efficient substrate channeling by exploiting the programmability of DNA origami to manipulate the key parameters of swinging arm length and stoichiometry. Compared with a single enzyme pair, the 2D organized enzyme systems exhibited higher reaction efficiency due to the promoted transfer of intermediates within the network.