Lithium rechargeable batterie

LiCo02, one of the most widely used cathode materials in lithium rechargeable batteries because of its high specific capacity, has been prepared in the form of... 

In lithium rechargeable batteries carbon materials are used that function as a lithium reservoir at the negative electrode. Reversible intercalation, or insertion, of lithium into the carbon host lattice avoids the problem of lithium dendrite formation and provides a large improvement in terms of cycleability and safety (111). 

There have been a number of attempts to produce commercial lithium rechargeable batteries. The V205 positive is currently used by the Matsushita Battery Industrial Co in Japan for the production of small capacity, coin-type cells. Fig. 7.24 shows a cross-section of one prototype. For the construction of the battery, V205 and carbon black are mixed together with a binder, moulded and vacuum-dried to form the positive electrode pellet. A solution of LiBF4 in a propylene carbonate-y-butyrolactone-1,2-dimethoxyethane mixture absorbed in a polypropylene separator is used as the electrolyte. 

Tatsumi K, Zaghib K, Abe H, Higuchi S, Ohsaki T, Sawada Y. A modification in the preparation process of a carbon whisker for the anode performance of lithium rechargeable batteries. J Power Sources 1995 54 425-427. 

Li H, Huang X, Chen L, Wu Z, Liang Y. A high capacity nano-Si composite anode material for lithium rechargeable batteries. Electrochem Solid-State Lett 1999 2 547-549. 

Iron vanadate, FeV04, is a prospective material for lithium rechargeable batteries and in catalysis. In [90] mechanical coactivation of iron and vanadium oxides was used to prepare intimate nanoscale mixture, similar to those prepared by soft chemistry. Reduction of this mixture at the same temperature and oxygen partial pressure conditions as of soft chemistry products (500°C and 10 Pa) leads to formation of a nanometric vanadium ferrite with the only spinel phase. The characterization of the powders thus prepared was perfomed by X-ray diffraction, SEM, IR spectrometry, thermogravimetry and colourimetry. It was shown that the homogeneity of grain size and chemical composition is achieved if the initial oxides have similar grain size. 

Nakahara K., Iriyama J., Iwasa S., Suguro M., Satoh M. and Cairns E. J. (2007b), High-rate capable organic radical cathodes for lithium-rechargeable batteries , J. Power Sources 165, 870-873. 

Initial measurements carried out on PEO-alkali metal salt complexes indicated that the observed conductivities were mostly ionic with little contribution from electrons. It should be noted that the ideal electrolyte for lithium rechargeable batteries is a purely ionic conductor and, furthermore, should only conduct lithium ions. Contributions to the conductivity from electrons reduces the battery performance and causes self-discharge on storage. Salts with large bulky anions are used in order to reduce ion mobility, since contributions to the conductivity from anions produces a concentration gradient that adds an additional component to the resistance of the electrolyte. 

While the development of primary cells with a lithium anode has been crowned by relatively fast success and such cells have filled their secure rank as power sources for portable devices for public and special purposes, the history of development of lithium rechargeable batteries was full of drama. Generally, the chemistry of secondary batteries in aprotic electrolytes is very close to the chemistry of primary ones. The same processes occur under discharge in both types of batteries anodic dissolution of lithium on the negative electrode and cathodic lithium insertion into the crystalline lattice of the positive electrode material. Electrode processes must occur in the reverse direction under charge of the secondary battery with a negative electrode of metallic lithium. Already at the end of the 1970s, positive electrode materials were found, on which cathodic insertion and anodic extraction of lithium occur practically reversibly. Examples of such compounds are titanium and molybdenum disulfides. 

Lee, Y. 2003. Chemically synthesized high molecular weight poly(2,2 -dithiodianiline) (PDTDA) as a cathode material for lithium rechargeable batteries. J Power Sources 119-121 321. 

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