Cathode Manufacturing for Lithium-Ion Batteries

Great efforts have been made in electrolyte development to achieve desirable hthium-ion conductivity, dielectric constant, viscosity, and thermal stabihty. The solvent systems include single solvent [35, 36] and cosolvent [37-44]. A mixture of ethylene carbonate (EC) and dimethyl carbonate/ethyl methyl carbonate (DMC/EMC) has been widely adopted by researchers and manufacturers [45-48]. liPFe is the preferred salt due to its overall performance [49]. An overview of electrolyte development is provided by Ahmad [49], and electrolyte processing has also been discussed elsewhere [50]. In addition, the introduction of hthium-ion 

Handbook of Battery Materials, Second Edition. Edited by Claus Daniel and Jurgen O. Besenhard. 

There are two typical cathodes composite cathodes and thin-fllm cathodes. Composite cathodes are fabricated by a process of casting, coating, or printing slurries. Fabrication of thin-fllm cathodes usually involves vacuum techniques. 

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For any battery applications, the separator should have uniform pore distribution to avoid performance losses arising from nonuniform current densities. The submicron pore dimensions are critical for preventing internal shorts between the anode and the cathode of the lithium-ion cell, particularly since these separators tend to be as thin as 25 pm or less. This feature will be increasingly important as battery manufacturers continue to increase the cell capacity with thinner separators. The pore structure is usually influenced by polymer composition, and stretching conditions, such as drawing temperature, drawing speed, and draw ratio. In the wet process, the separators produced by the process of drawing after extractirai... 

The technology of rechargeable lithium batteries is being developed continuously. Goals are larger batteries, e.g. for the hybrid propulsion system of vehicles, environmentally more compatible components, especially for the cathode, lower priced materials, longer cycle lives, more inert electrodes, etc. So-called solid-state batteries with polymeric electrolyte are also to be mentioned here. They are lithium-ion cells with an inert polymer matrix or a gel, which contains the electrolytic solvent-conductive salt mix. Herewith, the use of the normal heavy steel containers, which cannot be manufactured with heavily reduced wall thickness anyway, can be abandoned and a plastic laminated aluminum foil can be applied instead. In this way lightweight and very thin cells of a card format can be made. 

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