Lithium can be inserted reversibly within most carbonaceous materials. The physical mechanism for this insertion depends on the carbon type. Lithium intercalates in layered carbons such as graphite, and it adsorbs on the surfaces of single carbon layers in nongraphitizable hard carbons. Lithium also appears to reversibly bind near hydrogen atoms in carbonaceous materials containing substantial hydrogen, which are made by heating organic precursors to temperatures near 700°C. Each of these three classes of materials appears suitable for use in advanced lithium batteries.

A nonaqueous asymmetric electrochemical cell technology is presented where the positive electrode stores charge through a reversible nonfaradaic or pseudocapacitive reaction of anions on the surface of an activated carbon positive electrode. The negative electrode is a crystalline intercalation compound which supports the fast reversible intercalation of lithium ions. Using a positive electrode material of activated carbon and newly developed negative electrode material of nanostructured Li 4 Ti 5 O 12 we obtain a cell which exhibits a sloping voltage profile from 3 to 1.5 V, 90% capacity utilization at 10C charge/discharge rates, and 10-15% capacity loss after 5000 cycles. Electrolyte oxidation on the activated carbon positive electrode was characterized in a Li metal asymmetric hybrid cell by cyclic voltammetry. Oxidation during the anodic scan was found to decrease significantly after surface passivation at high voltage and elevated temperatures. We also introduce the asymmetric hybrid technology in a bonded flat plate plastic cell configuration where packaged energy densities were calculated to be in excess of 20 Wh/kg. In addition, a practical method for three-electrode analysis of Li cells by use of a Ag quasi-reference electrode wire is discussed.

No abstract

Fenton-like processes have been studied widely in recent years and are considered promising for organic wastewater treatment. Due to the demand for high efficiency wastewater treatment, a summary of the study status of Fenton-like processes is necessary to develop a novel and high efficiency organic wastewater treatment method. In this review, some important effect parameters (pH, H2O2 dosage, catalyst dosage, temperature) in hetero-/homo-geneous Fenton-like processes are discussed, and then the physical field/phenomenon-assisted hetero-/homo-geneous Fenton-like processes are presented. After that, catalyst types and the evaluation of wastewater treatment costs for various Fenton-like processes are summarized and discussed. Finally, possible future research directions and some guidelines for Fenton-like processes are given.

No abstract