New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.

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Nanostructured materials for advanced energy conversion and storage devices

Li-ion batteries have transformed portable electronics and will play a key role in the electrification of transport. However, the highest energy storage possible for Li-ion batteries is insufficient for the long-term needs of society, for example, extended-range electric vehicles. To go beyond the horizon of Li-ion batteries is a formidable challenge; there are few options. Here we consider two: Li-air (O(2)) and Li-S. The energy that can be stored in Li-air (based on aqueous or non-aqueous electrolytes) and Li-S cells is compared with Li-ion; the operation of the cells is discussed, as are the significant hurdles that will have to be overcome if such batteries are to succeed. Fundamental scientific advances in understanding the reactions occurring in the cells as well as new materials are key to overcoming these obstacles. The potential benefits of Li-air and Li-S justify the continued research effort that will be needed.

Li-O2 and Li-S batteries with high energy storage.

There is great interest in developing rechargeable lithium batteries with higher energy capacity and longer cycle life for applications in portable electronic devices, electric vehicles and implantable medical devices. Silicon is an attractive anode material for lithium batteries because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g(-1); ref. 2). Although this is more than ten times higher than existing graphite anodes and much larger than various nitride and oxide materials, silicon anodes have limited applications because silicon's volume changes by 400% upon insertion and extraction of lithium which results in pulverization and capacity fading. Here, we show that silicon nanowire battery electrodes circumvent these issues as they can accommodate large strain without pulverization, provide good electronic contact and conduction, and display short lithium insertion distances. We achieved the theoretical charge capacity for silicon anodes and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling.

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High-performance lithium battery anodes using silicon nanowires

2.1. Solvents 4307 2.1.1. Propylene Carbonate (PC) 4308 2.1.2. Ethers 4308 2.1.3. Ethylene Carbonate (EC) 4309 2.1.4. Linear Dialkyl Carbonates 4310 2.2. Lithium Salts 4310 2.2.1. Lithium Perchlorate (LiClO4) 4311 2.2.2. Lithium Hexafluoroarsenate (LiAsF6) 4312 2.2.3. Lithium Tetrafluoroborate (LiBF4) 4312 2.2.4. Lithium Trifluoromethanesulfonate (LiTf) 4312 2.2.5. Lithium Bis(trifluoromethanesulfonyl)imide (LiIm) and Its Derivatives 4313

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Nonaqueous liquid electrolytes for lithium-based rechargeable batteries.

Li-ion battery materials: present and future

Fundamentals.- Materials Aspects: An Overview.- The Role of Electronic Properties in the Electrochemical Behavior of Intercalation Compounds From a First Principles Vantage Point.- Synthesis of Battery Materials.- Anode Materials.- Anodes and Composite Anodes: An Overview.- Carbonaceous and Graphitic Anodes.- Graphite-Electrolyte Interface in Lithium-Ion Batteries.- The Key Role of Nanoparticles in Reactivity of 3D Metal Oxides Toward Lithium.- Nitride and Silicide Negative Electrodes.- Alloys and Intermetallic Anodes.- Current Issues of Metallic Lithium Anode.- Cathode Meterials.- Trends in Cathode Materials for Rechargeable Batteries.- Spinel Cathode Materials for Lithium-Ion Batteries.- Layered Manganese Oxides as Cathodes.- Cathodes Based on Lico02 and Lini02.- Polyanion-Based Positive Electrode Materials.- Understanding Phase Transformations in Lithium Battery Materials by Transmission Electron Microscopy.- Electrolytes.- Liquid Electrolytes: Some Theoretical and Practical Aspects.- Advanced Liquid Electrolyte Solutions.- Polymeric Electrolytes: An Overview.- Glass and Ceramic Electrolytes for Lithium and Lithium-Ion Batteries.- Battery Systems and Applications.- Lithium-Ion Batteries for Ev, Hev and other Industrial Applications.- Lithium Batteries for Medical Applications.- Current Issues and Market Trends of Li-Ion Batteries for Consumer Applications.

Lithium batteries : science and technology

Classical electrodes for Li-ion technology operate via an insertion/de-insertion process. Recently, conversion electrodes have shown the capability of greater capacity, but have so far suffered from a marked hysteresis in voltage between charge and discharge, leading to poor energy efficiency and voltages. Here, we present the electrochemical reactivity of MgH2 with Li that constitutes the first use of a metal-hydride electrode for Li-ion batteries. The MgH2 electrode shows a large, reversible capacity of 1,480 mAh g−1 at an average voltage of 0.5 V versus Li+/Li∘ which is suitable for the negative electrode. In addition, it shows the lowest polarization for conversion electrodes. The electrochemical reaction results in formation of a composite containing Mg embedded in a LiH matrix, which on charging converts back to MgH2. Furthermore, the reaction is not specific to MgH2, as other metal or intermetallic hydrides show similar reactivity towards Li. Equally promising, the reaction produces nanosized Mg and MgH2, which show enhanced hydrogen sorption/desorption kinetics. We hope that such findings can pave the way for designing nanoscale active metal elements with applications in hydrogen storage and lithium-ion batteries. Conversion electrodes for lithium-ion batteries are capable of high capacity but low energy efficiency and low voltages are problematic. The electrochemical reactivity of MgH2 with Li shows promise in using metal-hydride electrodes for both lithium-ion-battery and hydrogen storage applications.

Metal hydrides for lithium-ion batteries.

Preface. 1. Design and Optimization of Solid-State Batteries. 2. Materials for Electrolyte: Crystalline Compounds. 3. Materials for Electrolyte: Fast-Ion-Conducting Glasses. 4. Materials for Electrolyte: Thin Films. 5. Polymer Electrolytes. 6. Materials for Electrodes: Crystalline Compounds. 7. Materials for Electrodes: Amorphous and Thin-Films. 8. Applications of Solid-State Ionic Materials. Subject Index.

Solid State Batteries: Materials Design and Optimization

Raman and infrared spectroscopic studies and conductivity and viscosity measurements of propylene carbonate (PC) doped with various concentrations of lithium perchlorate are reported. The assignment of the vibrational modes was supplemented by AM1 normal coordinate analysis. Both Raman and infrared spectra showed band splitting in the fundamental vibrational frequencies of PC and perchlorate anion. Spectral curve fitting within the totally symmetric perchlorate band shape showed contributions of free ion, solvent-shared ion pairs, and contact ion pairs. Strong Li + -PC interaction was observed for the PC ring deformation band at 112 cm -1 . Ion pairing as deduced by spectroscopic techniques provided a rationale to account for conductivity and viscosity data

Vibrational studies of lithium perchlorate in propylene carbonate solutions

Electrolyte solutions formed by the addition of lithium perchlorate to a binary solvent mixture obtained by mixing ethylene carbonate (EC) with propylene carbonate (PC), diethyl carbonate (DEC), or dimethyl carbonate (DMC) were studied. The Raman spectra, conductivity, and viscosity of the EC based binary solvent electrolytes were measured. The salt concentration was optimized for maximum conductivity. Conductivity increases with increasing lithium perchlorate concentration in the EC/PC/LiClO4 electrolyte until a maximum of 6.1 kΩ-1 cm-1 is reached at 0.82 M LiClO4 (EC/PC/LiClO4 = 8/8/1). For the optimized salt concentration, the conductivity and viscosity dependence on the percent EC content of each electrolyte was measured at 25 °C. The maximum conductivity is observed for the EC/DMC/LiClO4 electrolyte at about 60% EC. The temperature dependence of conductivity and viscosity in the −30 ° to 60 °C range was also examined. The spectroscopic evidence for specific Li+ coordination is supported by quantum ch...

Gholam-Abbas Nazri

Papers

Lithium batteries : science and technology

Metal hydrides for lithium-ion batteries.

Solid State Batteries: Materials Design and Optimization

Vibrational studies of lithium perchlorate in propylene carbonate solutions

Raman Spectra and Transport Properties of Lithium Perchlorate in Ethylene Carbonate Based Binary Solvent Systems for Lithium Batteries