This manuscript reports the development of a safe and green lithium-ion battery using lithium iron phosphate (LiFePO4) as a positive electrode, graphite (Cgr) as a negative electrode, and an Ionic Liquid (IL) electrolyte solution based on 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)-imide (C1C6ImNTf2). Vinylene carbonate (VC) was tested as an electrolyte additive. The electrochemical stability of (C1C6ImNTf2) and their binary mixture referred as (Li)(C1C6ImNTf2) were investigated. In addition the electrochemical behavior of the graphite electrode was studied through cyclic voltammetry experiments in the presence and absence of VC co- additive. Complementary cycling tests demonstrated the benefic effect of VC on the charge-discharge performances for the full Lithium ion configuration based on Cgr/LiFePO4.

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A set of methoxy-substituted diindolo [3,2-b:2 0 ,3 0 -h]carbazoles has been synthesized by twofold SuzukiMiyaura, Cadogan and N-alkylation reactions starting from N-hexyl-2,7-dibromo-3,6-dinitro carbazole.Microwave accelerated reactions ensure a rapid straightforward and step-ecomomic assembly of the

For lithium ion batteries operating at elevated temperature, i.e., 333 K, an imidazolium based ionic liquid electrolyte, without any organic additives, was prepared by combining 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)-imide [C 1 C 6 ImNTf 2 ] and [LiNTf 2 ] (1.0 mol.L −1 ). This binary electrolyte [Li][C 1 C 6 Im][NTf 2 ], thermally stable up to 573 K, is ionically conductive (7.423 mS.cm −1 at 333 K). This electrolyte, in a full system configuration with Li 4 Ti 5 O 12 anode and LiFePO 4 cathode, displays a discharge capacity of 130-135 mA.h.g −1 at C/10 with a columbic efficiency of 98% at 333 K.During the last decade, lithium ion batteries have been a major power source for portable devices. 1,2 However, the volatility and flammability of electrolytes containing an organic solvent are serious safety drawbacks and risk factors in the use of Li-ion batteries in large scale applications, especially in electric (EV) and hybrid vehicles (HEV). 3-5 Development of safer and non-flammable electrolytes is of prime importance to many scientists dealing with lithium-ion batteries. Recently, Room Temperature Ionic Liquids (ILs) have been proposed as solvents for long-lived and safer lithium ion batteries, since they are generally non-flammable and have low volatility as well as superior thermal stability. [3][4][5][6][7][8] In recent years, lithium secondary batteries with carbon negative electrodes have been actively studied. However, graphite is not compatible with most ILs due to the irreversible electrochemical reduction of imidazolium cations on graphite, and to the intercalation of the alkylammonium, pyrrolidinium or piperidinium cations. 9,10 Using graphite as the negative active material of a lithium-ion system with ILs requires the presence of a solid electrolyte interface (SEI) on the graphite surface that allows reversible lithium insertion and deinsertion. [11][12][13] Recently, we investigated the use of [C 1 C 6 ImNTf 2 ] and [LiTNTf 2 ] at 1.6 M in combination with a graphite based electrode. 14,15 We have found low performances with graphite at 298 K and no significant improvement at elevated temperature. With ILs as electrolyte, the use of graphite as negative electrode presents to two major limits: exfoliation of graphite and use of an organic additive. 16 These two points could be crippling for the use of ILs as electrolytes. On the other hand, ILs are safer compared to organic electrolytes, and allow working at high temperature, thus opening a new domain of application for these batteries. Consequently, the development of full devices ion lithium batteries with ILs as electrolyte is still a scientific, environmental and economic challenge. 4,5 In this work, in order to overcome these limits, alternative negative electrodes, such as Ti-based oxides, e.g. Li 4 Ti 5 O 12 (LTO), have been tested. (LTO) has received significant attention as possible active materials to replace graphite. These materials have the disadvantage of reducing the energy density of conventional lithium-ion cells b...

In the last few years, ionic liquids (ILs) have revealed their broad versatility for application towards the synthesis of shape and size controlled nanoscale metal catalysts, respectively metal (0)

Tuning the chain-end functionality of a short-chain cationic homopolymer, owing to the nature of the initiator used in the atom transfer radical polymerization (ATRP) polymerization step, can be used to mediate the formation of a gel of this poly(electrolyte) in water. While a neutral end group gives a solution of low viscosity, a highly homogeneous gel is obtained with a phosphonate anionic moiety, as characterized by rheometry and diffusion nuclear magnetic resonance (NMR). This novel type of supramolecular control over poly(electrolytic) gel formation could find potential use in a variety of applications in the field of electro-active materials.

International audienceWe describe the preparation as well as the electrochemical and mechanical properties of a series of novel well-defined poly(ionic liquids) (PILs) featuring a finely tuned cross-linking ratio. We generate a variety of such PILs with various cationic moieties and cross-linking ratios starting from a common polymeric platform. Mixing those polymers with an appropriate ionic-liquid leads to ionogel electrolytes exhibiting good ionic conductivities (up to 1.2 mS cm−1 at 298 K), high electrochemical stability (up to 6 V) and a yield-stress fluid mechanical behavior, which enables their use as solid electrolytes. We demonstrate that depending on the cationic moieties, this ability to be solid at rest and reversibly fluid when sheared is obtained by two different mechanisms