Hybrid vehicles component technologies

A number of different lithium secondary systems serve for very low energy demands of electronic modules as memories and clocks. The batteries for these fields of application are manufactured as button cells. These cells are described first. Then for medium and high energy requirements lithium-ion batteries are explained. Today they are widely applied for portable electronic devices such as cellular phones and notebooks, which need much more energy than the aforementioned components for as many hours as possible (practically today up to 4 hours in notebooks). On the developmental stage it has been attempted to apply the lithium-ion technology also for much bigger accumulators, e.g. for so-called hybrid vehicles with a combined combustion and electric propulsion system. 

The incumbent technologies do not stand still, but continue to improve in performance, albeit within the envelope of the other components of the energy system—for example, more fuel-efficient internal combustion engine (ICE) vehicles and hybrid propulsion systems that make better use of the existing fueling infrastructure. 

Market success is an important criterion of any new drivetrain technology. Its benchmark is usually the cost of a conventional powertrain. In view of the different possible layouts, analyses should be based on production costs, not end-user price, and refer to mechanical power output to retain comparability in terms of driving performance. In a second step, life-cycle costs also need to be assessed in order to draft reliable conclusions. Figure 35.24 shows the specific costs of conventional ICE, hybrid, and BEV drivetrains for a vehicle with 90kWmech- Component costs are those stated in the previous sections. 

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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