Multi-component Olivine for Lithium-Ion Hybrid Capacitor

A lithium-ion hybrid capacitor comprising of a battery type multi-component olivine (LiMn1/3Co1/3Ni1/3PO4) cathode and a capacitive type carbon negative electrode is reported. Olivine phosphate synthesized with chelating agent's polyvinylpyrrolidone (PVP) or triethanolamine (TEA) showed uniform carbon coating through in-situ process exhibiting a surface area 5.1 m(2)/g with porosity 0.02 cm(3)/g. The surface area for commercial carbon electrode was observed to be 1450 m(2)/g with high porosity 0.76 cm(3)/g. Galvanostatic charge/discharge cycling tests were conducted in the coin cells, olivine vs. Li, offering a cell voltage of 4.75 V vs. Li with a maximum specific capacitance of 125 F/g. In the case of olivine vs. carbon in a lithium-ion hybrid device delivered a high discharge capacitance of 86 F/g at a specific current of 0.12 A/g with a cycling retention of 53 F/g (38% loss) after 250 cycles. The obtained performance of PVP synthesized olivine material is manifested to uniform carbon coating and the trapped organic products that provide pathways for facile electrochemical reactions than their TEA counterparts.

Oxygen-participated electrochemistry of new lithium-rich layered oxides Li3MRuO5 M = Mn, Fe)

We describe the synthesis, crystal structure and lithium deinsertion-insertion electrochemistry of two new lithium-rich layered oxides, Li3MRuO5 (M = Mn, Fe), related to rock salt based Li2MnO3 and LiCoO2. The Li3MnRuO5 oxide adopts a structure related to Li2MnO3 (C2/m) where Li and (Li0.2Mn0.4Ru0.4) layers alternate along the c-axis, while the Li3FeRuO5 oxide adopts a near-perfect LiCoO2 (R (3) over barm) structure where Li and (Li0.2Fe0.4Ru0.4) layers are stacked alternately. Magnetic measurements indicate for Li3MnRuO5 the presence of Mn3+ and low spin configuration for Ru4+ where the itinerant electrons occupy a pi*-band. The onset of a net maximum in the chi vs. T plot at 9.5 K and the negative value of the Weiss constant (theta) of -31.4 K indicate the presence of antiferromagnetic superexchange interactions according to different pathways. Lithium electrochemistry shows a similar behaviour for both oxides and related to the typical behaviour of Li-rich layered oxides where participation of oxide ions in the electrochemical processes is usually found. A long first charge process with capacities of 240 mA h g(-1) (2.3 Li per f.u.) and 144 mA h g(-1) (1.38 Li per f.u.) is observed for Li3MnRuO5 and Li3FeRuO5, respectively. An initial sloping region (OCV to ca. 4.1 V) is followed by a long plateau (ca. 4.3 V). Further discharge-charge cycling points to partial reversibility (ca. 160 mA h g(-1) and 45 mA h g(-1) for Mn and Fe, respectively). Nevertheless, just after a few cycles, cell failure is observed. X-ray photoelectron spectroscopy (XPS) characterisation of both pristine and electrochemically oxidized Li3MRuO5 reveals that in the Li3MnRuO5 oxide, Mn3+ and Ru4+ are partially oxidized to Mn4+ and Ru5+ in the sloping region at low voltage, while in the long plateau, O2- is also oxidized. Oxygen release likely occurs which may be the cause for failure of cells upon cycling. Interestingly, some other Li-rich layered oxides have been reported to cycle acceptably even with the participation of the O2- ligand in the reversible redox processes. In the Li3FeRuO5 oxide, the oxidation process appears to affect only Ru (4+ to 5+ in the sloping region) and O2- (plateau) while Fe seems to retain its 3+ state.

An alluaudite Na-2+Fe-2x(2-x)(SO4)(3)(x=0.2) derivative phase as insertion host for lithium battery

A new desodiated derivative compound, Na0.89Fe1.8(SO4)(3), was prepared by the chemical oxidation of alluaudite Na2.4Fe1.8(SO4)(3) Phase using NOBF4 as oxidant. The structure and valency of Fe were characterized by X-ray diffraction (XRD) and Fe-57 Mossbauer spectroscopy. Intercalation behavior of lithium ions in the structure of Na0.89Fe1.8(SO4)(3) was gauged by electrochemical analyses and ex-situ X-ray diffraction. A high capacity of 110 mAh g(-1) at 0.1 C was obtained with a good rate kinetics within a range of 0.1-10 C(1 C = 118 mAh g-1) involving a high Fe3+/Fe2+ redox potential of 3.75 V (vs. Li/Li+). These results confirmed that the Na2.4-delta Fe1.8(SO4)(3) framework was stable even after oxidation and forms a new competitive cathode for the reversible intercalation of lithium ions. (C) 2014 Elsevier B.V. All rights reserved.

Porous Flower-like alpha-Fe2O3 Nanostructure: A High Performance Anode Material for Lithium-ion Batteries

Porous flower-like alpha-Fe2O3 nanostructures have been synthesized by ethylene glycol mediated iron alkoxide as an intermediate and studied as an anode material of Li-ion battery. The iron alkoxide precursor is heated at different temperatures from 300 to 700 degrees C. The alpha-Fe2O3 samples possess porosity and high surface area. There is a decrease in pore volume as well as surface area by increasing the preparation temperature. The reversible cycling properties of the alpha-Fe2O3 nanostructures have been evaluated by cyclic voltammetry, galvanostatic charge discharge cycling, and galvanostatic intermittent titration measurements at ambient temperature. The initial discharge capacity values of 1063, 1168,1183, 1152 and 968 mAh g(-1) at a specific current of 50 mA g(-1) are obtained for the samples prepared at 300, 400, 500, 600 and 700 degrees C, respectively. The samples prepared at 500 and 600 degrees C exhibit good cycling performance with high rate capability. The high rate capacity is attributed to porous nature of the materials. As the iron oxides are inexpensive and environmental friendly, the alpha-Fe2O3 has potential application as anode material for rechargeable Li batteries. (C) 2015 Elsevier Ltd. All rights reserved.

Early postnatal exposure to lithium in vitro induces changes in AMPAR mEPSCs and vesicular recycling at hippocampal glutamatergic synapses

Lithium is an effective mood stabilizer but its use is associated with many side effects. Electrophysiological recordings of miniature excitatory postsynaptic currents (mEPSCs) mediated by glutamate receptor AMPA-subtype (AMPARs) in hippocampal pyramidal neurons revealed that CLi (therapeutic concentration of 1 mM lithium, from days in vitro 4-10) decreased the mean amplitude and mean rectification index (RI) of AMPAR mEPSCs. Lowered mean RI indicate that contribution of Ca2+-permeable AMPARs in synaptic events is higher in CLi neurons (supported by experiments sensitive to Ca2+-permeable AMPAR modulation). Co-inhibiting PKA, GSK-3 beta and glutamate reuptake was necessary to bring about changes in AMPAR mEPSCs similar to that seen in CLi neurons. FM1-43 experiments revealed that recycling pool size was affected in CLi cultures. Results from minimum loading, chlorpromazine treatment and hyperosmotic treatment experiments indicate that endocytosis in CLi is affected while not much difference is seen in modes of exocytosis. CLi cultures did not show the high KCl associated presynaptic potentiation observed in control cultures. This study, by calling attention to long-term lithium-exposure-induced synaptic changes, might have implications in understanding the side effects such as CNS complications occurring in perinatally exposed babies and cognitive dulling seen in patients on lithium treatment.

Lithium metal borate (LiMBO3) family of insertion materials for Li-ion batteries: a sneak peak

Rechargeable lithium-ion battery remains the leading electrochemical energy-storage device, albeit demanding steady effort of design and development of superior cathode materials. Polyanionic framework compounds are widely explored in search for such cathode contenders. Here, lithium metal borate (LiMBO3) forms a unique class of insertion materials having the lowest weight polyanion (i. e., BO33-), thus offering the highest possible theoretical capacity (ca. 220 mAh/g). Since the first report in 2001, LiMBO3 has rather slow progress in comparison to other polyanionic cathode systems based on PO4, SO4, and SiO4. The current review gives a sneak peak to the progress on LiMBO3 cathode systems in the last 15 years highlighting their salient features and impediments in cathode implementation. The synthesis and structural aspects of borate family are described along with the critical analysis of the electrochemical performance of borate family of insertion materials.

Energy-savvy solid-state and sonochemical synthesis of lithium sodium titanate as an anode active material for Li-ion batteries

Lithium sodium titanate insertion-type anode has been synthesized by classical solid-state (dry) and an alternate solution-assisted (wet) sonochemical synthesis routes. Successful synthesis of the target compound has been realized using simple Na- and Li-hydroxide salts along with titania. In contrast to the previous reports, these energy-savvy synthesis routes can yield the final product by calcination at 650 -750 degrees C for limited duration of 1-10 h. Owing to the restricted calcination duration (dry route for 1-2 h and wet route for 1-5 h), they yield homogeneous nanoscale lithium sodium titanate particles. Sono-chemical synthesis reduces the lithium sodium titanate particle size down to 80-100 nm vis-a-vis solid-state method delivering larger (200-500 nm) particles. Independent of the synthetic methods, the end products deliver reversible electrochemical performance with reversible capacity exceeding 80 mAh.g(-1) acting as a 1.3 V anode for Li-ion batteries. (C) 2015 Elsevier B.V. All rights reserved.

Ultra-small sulphur nanoparticles configured inside a flexible organic mixed conducting network as a cathode for lithium-sulphur batteries

The major challenges in Li-S batteries are the formation of soluble polysulphides during the reversible conversion of S-8 <-> Li2S, large changes in sulphur particle volume during lithiation and extremely poor charge transport in sulphur. We demonstrate here a novel and simple strategy to overcome these challenges towards practical realization of a stable high performance Li-S battery. For the first time, a strategy is developed which does away with the necessity of pre-fabricated high surface area hollow-structured adsorbates and also multiple nontrivial synthesis steps related to sulphur loading inside such adsorbates. A lithiated polyethylene glycol (PEG) based surfactant tethered on ultra-small sulphur nanoparticles and wrapped up with polyaniline (PAni) (abbreviated as S-MIEC) is demonstrated here as an exceptional cathode for Li-S batteries. The PEG and PAni network around the sulphur nanoparticles serves as an efficient flexible trap for sulphur and polysulphides and also provides distinct pathways for electrons (through PAni) and ions (through PEG) during battery operation. Contrary to the cathodes demonstrated based on various carbon-sulphur composites, the mixed conducting S-MIEC showed an extremely high loading of 75%. The S-MIEC exhibited a stable capacity of nearly 900 mA h g(-1) at the end of 100 cycles at a 1C current rate.

Conductometric Sensing of H-2 by Chromium Niobate

Investigations on chromium niobate (CrNbO4) have shown that the material responds to a wide hydrogen concentration range of 0.01%-0.40% at 613 K. The conductivity of CrNbO4 is independent of oxygen partial pressure and offers to be a promising candidate for monitoring H-2 in radioactive spent fuel storage facilities. Reduction of metal ions to lower valence states during hydrogen sensing was evidenced by X-ray photoelectron spectroscopic studies.

In Situ NMR Insights into the Electrochemical Reaction of Cu3P Electrodes in Lithium Batteries

This study reports a multinuclei in situ (real-time) NMR spectroscopic characterization of the electrochemical reactions of a negative Cu3P electrode toward lithium. Taking advantage of the different nuclear spin characteristics, we have obtained real-time P-31 and Li-7 NMR data for a comprehensive understanding of the electrochemical mechanism during the discharge and charge processes of a lithium battery. The large NMR chemical shift span of P-31 facilitates the observation of the chemical evolutions of different lithiated and delithiated LixCu3-xP phases, whereas the quadrupolar line features in Li-7 enable identification of asymmetric Li sites. These combined NMR data offer an unambiguous identification of four distinct LixCu3-xP phases, Cu3P, Li0.2Cu2.8P, Li2CuP, and. Li3P, and the characterization of their involvement in the electrochemical reactions. The NMR data led us to propose a delithiation process involving the intercalation of metallic Cu-0 atomic aggregates into the Li2CuP structure to form a Cu-0-Li2-xCu1-xP phase. This process might be responsible for the poor capacity retention in Cu3P lithium batteries when cycled to a low voltage.

Enhanced cycling performance and high energy density of LiFePO4 based lithium ion batteries

LiFePO4 attracts a lot of attention as cathode materials for the next generation of lithium ion batteries. However, LiFePO4 has a poor rate capability attributed to low electronic conductivity and low density. There is seldom data reported on lithium ion batteries with LiFePO4 as cathode and graphite as anode. According to our experimental results, the capacity fading on cycling is surprisingly negligible at 1664 cycles for the cell type 042040. It delivers a capacity of 1170 mAh for 18650 cell type at 4.5C discharge rate. It is confirmed that lithium ion batteries with LiFePO4 as cathode are suitable for electric vehicle application. (c) 2007 Elsevier B.V. All rights reserved.

Degenerated optical parametric chirped-pulse amplification with cesium lithium borate

A gain amplifier for degenerated optical parametric chirped-pulse amplification (OPCPA) with lithium triborate and cesium lithium borate (CLBO) crystals was demonstrated in a near-collinear configuration, The signal gain of the final energy amplifier with CLBO was similar to 6. After compression, the 123 fs pulse duration was obtained. Compared with potassium dihydrogen phosphate, it is confirmed that CLBO is more effective as a nonlinear crystal in a final power amplifier for terawatt or petawatt OPCPA systems. To our knowledge, this is the first demonstration of OPCPA with CLBO. (c) 2006 Optical Society of America.

Dendrites Inhibition in Rechargeable Lithium Metal Batteries

The specific high energy and power capacities of rechargeable lithium metal (Li⁰) batteries are ideally suited to portable devices and are valuable as storage units for intermittent renewable energy sources. Lithium, the lightest and most electropositive metal, would be the optimal anode material for rechargeable batteries if it were not for the fact that such devices fail unexpectedly by short-circuiting via the dendrites that grow across electrodes upon recharging. This phenomenon poses a major safety issue because it triggers a series of adverse events that start with overheating, potentially followed by the thermal decomposition and ultimately the ignition of the organic solvents used in such devices.

In this thesis, we developed experimental platform for monitoring and quantifying the dendrite populations grown in a Li battery prototype upon charging under various conditions. We explored the effects of pulse charging in the kHz range and temperature on dendrite growth, and also on loss capacity into detached “dead” lithium particles.

Simultaneously, we developed a computational framework for understanding the dynamics of dendrite propagation. The coarse-grained Monte Carlo model assisted us in the interpretation of pulsing experiments, whereas MD calculations provided insights into the mechanism of dendrites thermal relaxation. We also developed a computational framework for measuring the dead lithium crystals from the experimental images.

Stability of Electrode-Electrolyte Interfaces during Charging in Lithium Batteries

In this thesis we study the growth of a Li electrode-electrolyte interface in the presence of an elastic prestress. In particular, we focus our interest on Li-air batteries with a solid electrolyte, LIPON, which is a new type of secondary or rechargeable battery. Theoretical studies and experimental evidence show that during the process of charging the battery the replated lithium adds unevenly to the electrode surface. This phenomenon eventually leads to dendrite formation as the battery is charged and discharged numerous times. In order to suppress or alleviate this deleterious effect of dendrite growth, we put forth a study based on a linear stability analysis. Taking into account all the mechanisms of mass transport and interfacial kinetics, we model the evolution of the interface. We find that, in the absence of stress, the stability of a planar interface depends on interfacial diffusion properties and interfacial energy. Specifically, if Herring-Mullins capillarity-driven interfacial diffusion is accounted for, interfaces are unstable against all perturbations of wavenumber larger than a critical value. We find that the effect of an elastic prestress is always to stabilize planar interfacial growth by increasing the critical wavenumber for instability. A parametric study results in quantifying the extent of the prestress stabilization in a manner that can potentially be used in the design of Li-air batteries. Moreover, employing the theory of finite differences we numerically solve the equation that describes the evolution of the surface profile and present visualization results of the surface evolution by time. Lastly, numerical simulations performed in a commercial finite element software validate the theoretical formulation of the interfacial elastic energy change with respect to the planar interface.