In the previous paper Ralph Brodd and Martin Winter described the different kinds of batteries and fuel cells. In this paper I will describe lithium batteries in more detail, building an overall foundation for the papers that follow which describe specific components in some depth and usually with an emphasis on the materials behavior. The lithium battery industry is undergoing rapid expansion, now representing the largest segment of the portable battery industry and dominating the computer, cell phone, and camera power source industry. However, the present secondary batteries use expensive components, which are not in sufficient supply to allow the industry to grow at the same rate in the next decade. Moreover, the safety of the system is questionable for the large-scale batteries needed for hybrid electric vehicles (HEV). Another battery need is for a high-power system that can be used for power tools, where only the environmentally hazardous Ni/ Cd battery presently meets the requirements. A battery is a transducer that converts chemical energy into electrical energy and vice versa. It contains an anode, a cathode, and an electrolyte. The anode, in the case of a lithium battery, is the source of lithium ions. The cathode is the sink for the lithium ions and is chosen to optimize a number of parameters, discussed below. The electrolyte provides for the separation of ionic transport and electronic transport, and in a perfect battery the lithium ion transport number will be unity in the electrolyte. The cell potential is determined by the difference between the chemical potential of the lithium in the anode and cathode, ∆G ) -EF. As noted above, the lithium ions flow through the electrolyte whereas the electrons generated from the reaction, Li ) Li+ + e-, go through the external circuit to do work. Thus, the electrode system must allow for the flow of both lithium ions and electrons. That is, it must be both a good ionic conductor and an electronic conductor. As discussed below, many electrochemically active materials are not good electronic conductors, so it is necessary to add an electronically conductive material such as carbon * To whom correspondence should be addressed. Phone and fax: (607) 777-4623. E-mail: stanwhit@binghamton.edu. 4271 Chem. Rev. 2004, 104, 4271−4301

http://www.chemie.uni-regensburg.de/Anorganische_Chemie/Vortrag/StudentenWS06-07/Vortrag_Amereller.pdf

Lithium Batteries and Cathode Materials

LixCoO2 (0<x<-1): A new cathode material for batteries of high energy density

Oxide pyrochlores — A review

A single configuration model containing nonorthogonal magnetic orbitals is developed to represent the important features of the antiferromagnetic state of a transition metal dimer. A state of mixed spin symmetry and lowered space symmetry is constructed which has both conceptual and practical computational value. Either unrestricted Hartree–Fock theory or spin polarized density functional theory, e.g., Xα theory, can be used to generate the mixed spin state wave function. The most important consequence of the theory is that the Heisenberg exchange coupling constant J can be calculated simply from the energies of the mixed spin state and the highest pure spin multiplet.

Valence bond description of antiferromagnetic coupling in transition metal dimers

The surface and materials science of tin oxide

Synthesis, crystal structure and molecular conformations, and magnetic properties of a copper-vanadyl (CuII-VOII) heterobinuclear complex: interaction between orthogonal magnetic orbitals

Vanadium pentoxide and vanadium oxide bronzes—Structural chemistry of single (S) and double (D) layer MxV2O5 phases

Piezoelectric andferroelectric ceramicmaterialsarematureand ubiquitous materials for advanced technology. Theseceramics are the active elements in a range of piezoelectricdevices and perform functions such as sensing and actuation.The performance of these materials is closely related to theirmicrostructures and, for this reason, to the ways they havebeen processed. The ﬁrst step in obtaining high-performanceceramics with a homogeneous microstructure and controlledgrain size that meet the requirements of industry isto preparepowderswithcontrolledstoichiometryandsmallparticlesize.However, even if a small-size powder is used, conventionalsintering is often unable to provide dense, very ﬁne-grainedceramics, due to the high temperatures still required fordensiﬁcation,andthefactthatthelowestgrainsizeachievableby classical techniques remains about 0.5mm or even higher,depending on the system. To solve this problem, the masstransport during the sintering step must be enhanced, sincethe temperature and time needed for consolidation must bereduced in order to achieve smaller grain sizes. Among themethods reported for activation of the mass transportduring the sintering process, the application of an electricalcurrent through the sample during heating represents apromising technique for rapid densiﬁcation of ceramics atrelatively low temperatures. The most novel and increas-ingly used method is spark plasma sintering, which hasclear advantages over conventional sintering methods,making it possible to sinter nanometric powders to nearfull densiﬁcation with little grain growth. This has becomeincreasingly important recently, with the miniaturization ofelectronic devices and the need to investigate size effects onthe properties in the sub-micrometer range and approach-ing the nanometer scale ( 100nm).In many material applications there is a need for densematerials, often being very close to their theoretical density.Unfortunately, taking account the fragility and refractoryproperties of ceramic materials and several difﬁcultiesinherent in the sintering process, the compaction withoutany additives becomes a real challenge from both practicaland theoretical aspects.The ﬁnal electromechanical properties of piezoelectricceramic components greatly depend upon the history of theceramic. Each step in the preparation of the material has to becarefully monitored and controlled toobtain the best product.The primary steps of the preparation of the ceramic materialaresynthesisoftheprecursor,fabricationofgreenbodiesand,last but not least, sintering of the pellet to achieve properdensiﬁcation. This third step, which follows powder prepara-tion, consists of thermal treatment with the aim of strengthen-ing the desired piece. It occurs via bonding of the compactgrains without melting. Such ‘‘welding’’ may be followed

https://www.icmm.csic.es/ac/publications/publication10.pdf

Spark Plasma Sintering as a Useful Technique to the Nanostructuration of Piezo-Ferroelectric Materials**

Microstructures and mechanical properties of TiAl alloys consolidated by spark plasma sintering

Temperature, holding time and conditions of pressure application, three of the most important spark plasma sintering (SPS) parameters, have been reviewed to assess their effect on the densification and grain growth kinetics of a pure commercially available submicrometer-sized silicon carbide powder. Experiments were performed in the 1750–1850 °C temperature range with holding time from 1 to 10 min. Two pressure setups were used: one with pressure (75 MPa) applied at 1000 °C and the other with ultimate pressure applied at sintering temperature. Experimental data highlighted the fact that temperature and holding time have a different impact on grain growth and densification. Diffusion and migration mechanisms that promote grain growth were found to be strongly dependent on temperature, the latter being linked to pulsed current intensity. Conditions of pressure application suggest that the ultimate pressure applied at higher temperature increases densification by keeping small surface contact between particles.

Jean Galy

Papers

Synthesis, crystal structure and molecular conformations, and magnetic properties of a copper-vanadyl (CuII-VOII) heterobinuclear complex: interaction between orthogonal magnetic orbitals

Vanadium pentoxide and vanadium oxide bronzes—Structural chemistry of single (S) and double (D) layer MxV2O5 phases

Spark Plasma Sintering as a Useful Technique to the Nanostructuration of Piezo-Ferroelectric Materials**

Microstructures and mechanical properties of TiAl alloys consolidated by spark plasma sintering

Densification of SiC by SPS-effects of time, temperature and pressure