Intercalation lithium polymer batteries

In lithium polymer batteries, one electrode is lithium foil, or in some cases another electrically conducting material such as graphite, and the other is a reversible intercalation compound as in liquid electrolyte lithium batteries. Compounds used as intercalation electrodes include LiCo02 and VeOis. The cell developed in the Anglo-Danish project, which ran from 1979 to 1995, was... 

This type of Li battery has already widely diffused in the electronic consumer market, however for automotive applications the presence of a liquid electrolyte is not considered the best solution in terms of safety, then for this type of utilization the so-called lithium polymer batteries appear more convenient. They are based on a polymeric electrolyte which permits the transfer of lithium ions between the electrodes [21]. The anode can be composed either of a lithium metal foil (in this case the device is known as lithium metal polymer battery) or of lithium supported on carbon (lithium ion polymer battery), while the cathode is constituted by an oxide of lithium and other metals, of the same type used in lithium-ion batteries, in which the lithium reversible intercalation can occur. For lithium metal polymer batteries the overall cycling process involves the lithium stripping-deposition at the anode, and the deintercalation-intercalation at the anode, according to the following electrochemical reaction, written for a Mn-based cathode ... 

Lithium-polymer batteries (LPBs) use intercalated carbon for the negative electrode, a polymer electrolyte, and metallic lithium that is deposited as a thin film as the negative electrode. This battery type is under development but not yet introduced to the market for electric vehicles. 

It is perhaps useful to mention that the use of electronically conducting polymers, such as poly(acetylene), (CH) poly(pyrrole), (C4H5N)X, and poly(aniline), (CeHgNf ), has been proposed for positives for lithium batteries. The electrochemical process of these lithium-polymer positives is somewhat similar to an intercalation reaction. On charging, the polymer (P) is oxidized by acquiring a positive charge to form a polaron, and this is... 

Murugan et al. reported on the intercalation of electrically conductive poly(3,4-ethylene dioxythiophene) (PEDOT) into crystalline V2O5. PEDOT is a stable, environmentally friendly polymer with potential applications in supercapacitors and lithium ion batteries. PEDOT was encapsulated into V2O5 by treatment of the latter with the monomer (3,4-ethylene dioxythiophene). The reaction is essentially an in situ... 

Attempts were made to discover the correlation between the crystalline structure of carbonaceous materials and their capability to reversibly intercalate lithium. This correlation has not been definitely established, but still, one can assume as a certain general principle that the optimum materials would contain an amorphous matrix with inclusions of a mesophase nuclei of graphite crystallites. Such materials are various cokes, pyrographite, and products of pyrolysis (carbonization) of various polymers. For practical purposes, the industry mastered some special materials providing high characteristics of negative electrodes in lithium ion batteries. The most popular material is manufactured by the Japanese company of Osaka Gas Co. under the name of mesocarbon microbeads, MCMB it represents the carbonization product of pitchy resins under a certain temperature regime. 

The feasibility of the gel electrolytes for lithium-ion batteries development has been tested by first examining their compatibility with appropriate electrode materials, i.e., the carbonaceous anode and the lithium metal oxide cathode. This has been carried out by examining the characteristics of the lithium intercalation-deintercalation processes in the electrode materials using cells based on the given polymer as the electrolyte and lithium metal as the counter electrode. 

A recent solid state battery design, lithium composite cathode batteries, developed at Harwell, features a lithium ion conducting polymer electrolyte (e.g., polyethylene oxide) and a solid intercalation cathode. The battery is made up of a sandwich of lithium foil (50 pm), polymer-electrolyte (50 pm), composite cathode (various types have been studied including VsOis, TiS2, MoOj, etc., plus 5% carbon black) (56 ym) and a nickel foil current collector (10 pm). Thus total cell thickness is 150-200 pm and areas can range from cm to m. ... 

It has been known for some time that lithium can be intercalated between the carbon layers in graphite by chemical reaction at a high temperature. Mori et al. (1989) have reported that lithium can be electrochemically intercalated into carbon formed by thermal decomposition to form LiCg. Sony has used the carbon from the thermal decomposition of polymers such as furfuryl alcohol resin. In Fig. 11.23, the discharge curve for a cylindrical cell with the dimensions (f) 20 mm x 50 mm is shown, where the current is 0.2 A. The energy density for a cutoff voltage of 3.7 V is 219 W h 1 which is about two times higher than that of Ni-Cd cells. The capacity loss with cycle number is only 30% after 1200 cycles. This is not a lithium battery in the spirit of those described in Section 11.2. 

The benefit of a hybrid phase for the intercalation-deintercalation of mobile species such as Li+ cations is well illustrated by the study of conductive polymers such as polyaniline or polypyrrole intercalated into a V2O5 framework as potential electrode materials in lithium batteries [34]. For PANI/V2O5, an oxidative post-treatment performed under an oxygen atmosphere allowed the authors to compare the conductivity attributed to the polymer, as in absence of reduced cations, there was no electronic hopping between ions, and the conductive state was due only to the... 

Whittingham in the seventies developed a battery that operated at room temperature based on the intercalation of Li in TiS2. In the lithium/titanium disulfide battery, one electrode is lithium metal and the other is titanium disulfide bonded to a polymer such as teflon. The electrolyte is a lithium salt dissolved in an organic solvent. Typically, the... 

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