Application for Lithium Batteries

The rechargeable Li-air battery has attracted intensive attention since it is able to produce very high specific energies, 3505 W h/kg based on the reaction 2Lin-02 

Li202 in nonaqueous media. Cheng and Scott prepared a Li metal-compatible and Li metal-stable Li-Naflon binder and membrane, which is used to construct a novel rechargeable Li-02/air solid battery. The resulted battery achieved a high capacity over 1000 mA h/(g solids) with good rate capability and capacity retention. 

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Lithium vanadate bronzes are intercalated compounds with potential applications for lithium battery technology, since Li can be reversibly inserted into these stmctures by electrochemical reaction. Li NMR has been used to study the stmcture of 7-Lio.95V205 (Cocciantelli et al. 1992) and a series of related bronzes LixV205 (Cocciantelli et al. 1992a). The Li NMR spectrum of the -y-phase indicates the presence of a single Li site, but as the Li content is increased beyond x = 1, new lines can be resolved, corresponding... 

Polyphosphazenes have emerged as a class of promising solid polymer electrolyte materials for energy applications due to their inherently high stability and a wide range of synthetic variability. Herein, a summary is presented on the synthesis of polyphosphazenes, membrane fabrication and characterization, and applications for lithium batteries, fuel cells, and dye-sensitized solar cells (DSSCs). 

Electronic and Electrical Applications. Sulfolane has been tested quite extensively as the solvent in batteries (qv), particularly for lithium batteries. This is because of its high dielectric constant, low volatUity, exceUent solubilizing characteristics, and aprotic nature. These batteries usuaUy consist of anode, cathode polymeric material, aprotic solvent (sulfolane), and ionizable salt (145—156). Sulfolane has also been patented for use in a wide variety of other electronic and electrical appHcations, eg, as a coil-insulating component, solvent in electronic display devices, as capacitor impregnants, and as a solvent in electroplating baths (157—161). 

Li-Mn02 batteries are available in a variety of shapes and construction [30] in accordance with their particular use. Figure 32 shows various applications of lithium batteries based on their drain current. Coin-type batteries are generally used for low-rate drain. Cylindrical batteries with the inside-out construction can serve as a... 

The composition of lithium-manga-nese-oxide spinel electrodes that are of interest for lithium battery applications fall within the Li[Mn2]04 - Li4Mn5Ot2 -Li2[Mn4]0() tie-triangle of the Li-Mn-0... 

Bridged polysilsesquioxanes having covalently bound acidic groups, introduced via modification of the disulfide linkages within the network, were studied as solid-state electrolytes for proton-exchange fuel cell applications.473 Also, short-chain polysiloxanes with oligoethylene glycol side chains, doped with lithium salts, were studied as polymer electrolytes for lithium batteries. 

The lilhium-Uiiouyl chluridc, or die lithium-sulfur dioxide, system is often used in a reserve battery configuration in which the electrolyle is slored in a sealed compartment which upon activation may be forced by a piston or inertial forces into the interelectrode space. Most applications for such batteries arc in mines and fuse applications in military ordnance. 

Green M, Fielder E, Scrosati B, Wachtler M, Moreno JS. Structured silicon anodes for lithium battery applications. Electrochem Solid-State Lett 2003 6 A75-A79. 

Room-temperature ionic liquids (denoted RTILs) have been studied as novel electrolytes for a half-century since the discovery of the chloroaluminate systems. Recently another system consisting of fluoroanions such as BF4 and PFg , which have good stability in air, has also been extensively investigated. In both systems the nonvolatile, noncombustible, and heat resistance nature of RTILs, which cannot be obtained with conventional solvents, is observed for possible applications in lithium batteries, capacitors, solar cells, and fuel cells. The nonvolatility should contribute to the long-term durability of these devices. The noncombustibility of a safe electrolyte is especially desired for the lithium battery [1]. RTILs have been also studied as an electrodeposition bath [2]. 

A further interesting effect discovered in our laboratories is that the addition of low levels of a second component, or dopant ion, can lead to significant increases in the ionic conductivity [6, 30, 31]. Typically these dopant species, for example, Li, OH , and H" ", are much smaller than the organic ions of the matrix, and since the relaxation times characterizing the motion of these ions are more rapid than those of the bulk matrix itself, these materials may represent a new class of fast ion conductor. The dopant ion effect can be used to design materials for specific applications, for example, Li+ for lithium batteries and H /OH for fuel cells or other specific sensor applications. Finally, we have recently discovered that this dopant effect can also be apphed to molecular plastic crystals such as succinonitrile [32]. Such materials have the added advantage that the ionic conductivity is purely a result of the dopant ions and not of the solvent matrix itself. 

There are two main kinds of rechargeable battery based on lithium chemistry the lithium-metal and the lithium-ion battery. In both the positive electrode is a lithium insertion material the negative in the former is lithium metal and in the latter it is a lithium insertion host. The reason for the application in lithium batteries of insertion electrode materials, which are electronic and ionic conductive solid matrixes (inorganic and carbon-based), is that electrochemical insertion reactions are intrinsically simple and highly reversible. 

The cathodic incorporation of lithium from a solution of LiAsFg in propylene carbonate was used in the attempt [301] to obtain HTSC materials based on calcium and lanthanum niobates. The incorporation of lithium into YBCO from a similar electrolyte proceeds reversibly and ensures a discharging capacitance of the HTSC cathode high enough for application in lithium batteries [302-307]. The possibility was also reported [308-310] of incorporating lithium into BSCCO, but the capacitance values obtained are very contradictory. 

One of the most important practical applications of lithium compounds is as fast ion conductors with potential electronic applications such as solid electrolytes for lithium batteries. Li20 is a fast ion conductor in which the Li ions occupy a simple cubic sublattice with the antifluorite structure. Both MAS and static Li NMR spectra of Li20 have been reported, the former recorded as a function of temperature up to 1000 K (Xie et al. 1995). The effect of introducing vacancies on the Li sites by doping with LiF has been studied by high-temperature static Li NMR, which reveals the interaction of the Li defects > 600 K and the appearance of 2 distinct quadrupolar interactions at about 900 K. Measurements of the relative intensities of the satellite peaks as a function of temperature have provided evidence of thermal dissociation of an impurity-vacancy complex (Xie et al. 1995). 

With regard to their application in lithium batteries, CNTs exhibit large hysteresis and irreversible capacity, two properties that made their practical application difficult. The mesoporous character of CNTs is responsible for the ease in evacuation of Li, thus determining hysteresis, as well as for the ease in access of solvated ions to the active surface, thereby determining irreversible capacity (Frackowiak and Beguin, 2002). 

Thackeray, M. M., J. O. Thomas, and M. S. Whittingham. 2002. Theme article—Science and applications of mixed conductors for lithium batteries.mrs.org... 

Mesoporous C03O4 showed superior capacity at high rates for lithium battery applications compared with bulk materials. Mesoporous... 

Kurian, M., Galvin, M. E., Trapa, P. E., Sadoway, D. R., Mayes,A. M. (2005). Single-ion conducting polymer-silicate nanocomposite electrol3rtes for lithium battery applications, Electrochim. Acta. 50(10), 2125-2134. 

Azizi Samir et al. [155] have studied the possibility to reinforce thin films of polymer electrolytes for lithium battery applications. They reinforced polyoxyethylene with tunicate whiskers. The results showed that the storage modulus and temperature stability was greatly improved, and the ionic conductivity was maintained. 

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