Microbial pyrazine diamine is a novel electrolyte additive that shields high-voltage LiNi1/3Co1/3Mn1/3O2 cathodes.

The uncontrolled oxidative decomposition of electrolyte while operating at high potential (> 4.2 V vs Li/Li+) severely affects the performance of high-energy density transition metal oxide-based materials as cathodes in Li-ion batteries. To restrict this degradative response of electrolyte species, the need for functional molecules as electrolyte additives that can restrict the electrolytic decomposition is imminent. In this regard, bio-derived molecules are cost-effective, environment friendly, and non-toxic alternatives to their synthetic counter parts. Here, we report the application of microbially synthesized 2,5-dimethyl-3,6-bis(4-aminobenzyl)pyrazine (DMBAP) as an electrolyte additive that stabilizes high-voltage (4.5 V vs Li/Li+) LiNi1/3Mn1/3Co1/3O2 cathodes. The high-lying highest occupied molecular orbital of bio-additive (DMBAP) inspires its sacrificial in situ oxidative decomposition to form an organic passivation layer on the cathode surface. This restricts the excessive electrolyte decomposition to form a tailored cathode electrolyte interface to administer cyclic stability and enhance the capacity retention of the cathode.

Extremely fast charging lithium-ion battery using bio-based polymer-derived heavily nitrogen doped carbon.

Extremely high nitrogen doped carbon was designed by facile pyrolysis of bio-based poly(2,5-benzimidazole) as a single source of nitrogen and carbon. For the first time ever, a carbon-based anode with ∼17 wt% of nitrogen doping with extremely fast charging (XFC) capability at 18.6 A g-1 and ultralong cyclability (3000 cycles) with 90% capacity retention was investigated. Full cell studies also indicated the commercial competence of the novel material.

An all solid-state Li ion battery composed of low molecular weight crystalline electrolyte.

Conduction mechanisms in solid polymer electrolytes of Li ion batteries have always been a concern due to their theoretical limitation in conductivity value. In an attempt to increase the ionic conductivity of solid state electrolytes, used in lithium ion secondary batteries (LiBs), we studied the synthesis and conductive properties of a low molecular weight cyclic organoboron crystalline electrolyte. This electrolyte was expected to show better electrochemical properties than solid polymer electrolytes. The electrolyte was doped with LiTFSI salt via two different methods viz. (1) facile grinding of the crystalline sample with lithium salt under a nitrogen atmosphere and (2) a conventional method of solvent dissolution and evaporation under vacuum. The electrochemical properties were studied under specific composition of Li salt. The presence of crystallinity in the electrolyte can be considered as an important factor behind the high ionic conductivity of an all solid electrolyte of this type. Charge-discharge properties of the cell using the electrolyte were investigated in anodic half-cell configuration.

Controlled Phase Behavior of Thermally Sensitive Poly(N-isopropylacrylamide/ionic liquid) with Embedded Au Nanoparticles.

We have synthesized a series of poly(N-isopropylacrylamide/ionic liquid) with deposited Au nanoparticles. The size of the nanoparticle range was varied from 10 to 35 nm, and these were characterized by transmission electron microscopy analysis. Ionic liquids (IL) were chosen by varying the polymerizable unit to be both in cationic (allyl) and anionic (acrylate) moiety. One-pot polymerization was done with N-isopropylacrylamide and IL using ammonium persulphate as the initiator, to which were added already prepared Au NPs. These thermally sensitive composites formed, possessed reversible swelling/deswelling abilities in water, and demonstrated a reversible visible phase transition, which was detected by differential scanning calorimetric measurements. The lower critical solution temperature (LCST) showed dependency on the size of nanoparticles and the IL independently. It was seen that the LCST of PNIPAM-based composite films can be tuned from 32 °C to a range of 23-67 °C by choosing the desired Au NP size, its concentration and kind of IL.

Few-Layered MoS2/Acetylene Black Composite as an Efficient Anode Material for Lithium-Ion Batteries.

Novel MoS2/acetylene black (AB) composite was developed using a single-step hydrothermal method. A systematic characterization revealed a few-layered, ultrathin MoS2 grown on the surface of AB. The inclusion of AB was found to increase the capacity of the composite and achieve discharging capacity of 1813 mAhg-1.

Nano-sized Mo- and Nb-doped TiO2 as anode materials for high energy and high power hybrid Li-ion capacitors.

Nano-sized Mo-doped titania (Mo0.1Ti0.9O2) and Nb-doped titania (Nb0.25Ti0.75O2) were directly synthesized via a continuous hydrothermal flow synthesis process. Materials characterization was conducted using physical techniques such as transmission electron microscopy, powder x-ray diffraction, x-ray photoelectron spectroscopy, Brunauer-Emmett-Teller specific surface area measurements and energy dispersive x-ray spectroscopy. Hybrid Li-ion supercapacitors were made with either a Mo-doped or Nb-doped TiO2 negative electrode material and an activated carbon (AC) positive electrode. Cells were evaluated using electrochemical testing (cyclic voltammetry, constant charge discharge cycling). The hybrid Li-ion capacitors showed good energy densities at moderate power densities. When cycled in the potential window 0.5-3.0 V, the Mo0.1Ti0.9O2/AC hybrid supercapacitor showed the highest energy densities of 51 Wh kg-1 at a power of 180 W kg-1 with energy densities rapidly declining with increasing applied specific current. In comparison, the Nb0.25Ti0.75O2/AC hybrid supercapacitor maintained its energy density of 45 Wh kg-1 at 180 W kg-1 better, showing 36 Wh g-1 at 3200 W kg-1, which is a very promising mix of high energy and power densities. Reducing the voltage window to the range 1.0-3.0 V led to an increase in power density, with the Mo0.1Ti0.9O2/AC hybrid supercapacitor giving energy densities of 12 Wh kg-1 and 2.5 Wh kg-1 at power densities of 6700 W kg-1 and 14 000 W kg-1, respectively.

Sacrificial Reducing Agent Free Photo-Generation of Platinum Nano Particle over Carbon/TiO2 for Highly Efficient Oxygen Reduction Reaction.

Electrocatalytic materials for oxygen reduction reaction, currently dominated by platinum/carbon catalyst is marred by drawbacks such as use of copious amount of Pt and use of "non-green" sacrificial reducing agent (SRA) during its synthesis. A single stroke remedy for these two problems has been achieved through an in-situ aqueous photoreduction void of even trace amounts of SRA with an enhanced activity. Reduction of PtCl62- salt to Pt nano particles on carbon substrate was achieved solely using solar spectrum as the source of energy and TiO2 as photocatalyst. Here, we demonstrate that this new procedure of photoreduction, decorates Pt over different types of conducting allotropes with the distribution and the particle size primarily depending on the conductivity of the allotrope. The Pt/C/TiO2 composite unveiled an ORR activity on par to the most efficient Pt based electrocatalyst prepared through the conventional sacrificial reducing agent aided preparation methods.

A crystalline low molecular weight cyclic organoboron compound for efficient solid state lithium ion transport.

We report the synthesis of a crystalline cyclic organoboron compound that shows an anomalous Li-ion conduction behaviour with specific composition and method of insertion of a Li salt. The enhanced ionic conductivity of crystalline boric ester/LiTFSI prepared by the grinding method should be due to the formation of regulated ion-conduction channels scaffolded by boron-anion interaction.

Platinum decorated functionalized defective acetylene black; a promising cathode material for the oxygen reduction reaction.

A novel single-pot method to exfoliate and functionalize acetylene black is proposed. The deliberate functionalization was found to enhance the intrinsic oxygen reduction efficiency along with the nucleation and growth of platinum nano-particles on the surface. The resulting material showed enormously high oxygen reduction reactivity compared to its commercial counterparts.

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.

Electrochemical characterization of TiO2/WOx nanotubes for photocatalytic application.

TiO2/WOx nanotubes have unique photo-energy retention properties that have gathered scientific interest. Herein, we report the synthesis, morphological characterization, and the electrochemical characterization of TiO2/WOx nanotubes compared with pure TiO2 nanotubes, prepared by anodization technique. Significant structural differences were not observed in TiO2/WOx nanotubes as observed by using scanning electron microscopy and transmission electron microscopy. The charge transfer resistance of TiO2/WOx before and after photo irradiation determined by using electrochemical impedance spectroscopy proves the inherent energy retention property which was not observed in pure TiO2 nanotubes.

Lysine pyrrolation is a naturally-occurring covalent modification involved in the production of DNA mimic proteins.

Covalent modification of proteins exerts significant effects on their chemical properties and has important functional and regulatory consequences. We now report the identification and verification of an electrically-active form of modified proteins recognized by a group of small molecules commonly used to interact with DNA. This previously unreported property of proteins was initially discovered when the γ-ketoaldehydes were identified as a source of the proteins stained by the DNA intercalators. Using 1,4-butanedial, the simplest γ-ketoaldehyde, we characterized the structural and chemical criteria governing the recognition of the modified proteins by the DNA intercalators and identified N(ε)-pyrrolelysine as a key adduct. Unexpectedly, the pyrrolation conferred an electronegativity and electronic properties on the proteins that potentially constitute an electrical mimic to the DNA. In addition, we found that the pyrrolated proteins indeed triggered an autoimmune response and that the production of specific antibodies against the pyrrolated proteins was accelerated in human systemic lupus erythematosus. These findings and the apparent high abundance of N(ε)-pyrrolelysine in vivo suggest that protein pyrrolation could be an endogenous source of DNA mimic proteins, providing a possible link connecting protein turnover and immune disorders.

Ionic liquid pillar[5]arene: its ionic conductivity and solvent-free complexation with a guest.

A room-temperature ionic liquid containing macrocyclic compound pillar[5]arene in its core was synthesized. The ionic liquid showed high thermal stability, moderate ionic conductivity and solvent-free complexation ability with the guest tetracyanoethylene.

Lithium ion conduction in an organoborate zwitterion-LiTFSI mixture.

An organoborate zwitterion-lithium salt mixture, prepared via selective borate formation of N-ethylimidazolium salt, exhibited ionic conductivity of 3.0 x 10(-5) S cm(-1) at 50 degrees C and a lithium transference number of 0.69.

Liquid imidazole-borane complex.

Physical properties of liquid imidazole-borane complex were investigated to demonstrate their utility as aprotic polar solvents or liquid electrolytes appropriate for selective ion transport.

Molten salts bearing anion receptor.

A series of organoboron molten salts prepared by hydroboration of allyl imidazolium type molten salts with various hydroborating reagents such as monobromoborane dimethyl sulfide complex, 9-borabicyclo[3.3.1]nonane (9-BBN) and mesitylborane, and subsequent anion exchange reaction exhibited selective cation transporting property with ionic conductivity of 7.79 x 10(-5) - 6.25 x 10(-6) S cm(-1) at 323 K.