Li-Ion Battery Technology Past and Present

Schematic comparison between the different potential windows in the three successive generations of rocking-chair systems. Reprinted from Ref. [41], with permission from Elsevier. 

An intercalation potential very close to the reduction of Li ions may also lead to metallic Li electrodeposition on the graphite electrode. The metallic lithium formed in this way is a finely divided powder that, unsurprisingly, is highly reactive, making the batteiy veiy unstable. This situation may occur in the event of an accidental overcharge of the battery. Practically, today all the commercial battery packs include electronics that monitor the batteiy and prevent overchai ng. 

Needless to say, that an insufficient thermal design of the batteiy assembty or an accidental slight overcharge may lead to the catastrophic destruction of the battery by the phenomenon of thermal runaway. The losses suffered recently by some battery and laptop computers manufacturers that needed to recall a large number of faulty batteries constitute an eloquent illustration, in economic terms, of the importance that this phenomenon may acquire. 

From an economical point of view, graphite will probably never be surpassed by other materials, but the fabrication of electrodes showing better properties is still required. Therefore, other active materials that can serve as anodes have to be 

Very recentty, improvement in rate capability, capacity, and cycling behavior has been observed in the case of nanostructured titania, strengthening the possibility to use this oxide as a negative material for Li-ion batteries. Bruce and Lindsay have reported that the crystallite size and shape play key roles for improving the performances of the electrodes [22, 23], It also has to be noted that their investigation concerned either hydrothermal synthesized Ti02 nanotubes or anodic oxide thin 

---