NANOSTRUCTURED TiO2 MATERIALS FOR NEW-GENERATION Li-ION BATTERIES - Electrochemical Nanofabrication: Principles and Applications - page 188

for the next years. Ni-Cd, Ni-MH, and Pb-acid-type batteries can
supply excellent pulsed power, but their large size and heavy weight
hinders an optimal application in EV. On the contrary, lithium-ion
batteries are well-suited for their use in high-performance electric
vehicles. Lithium-ion provides very high specific energy and a large
number of charge-discharge cycles [10]. In turn, several drawbacks
remain unsolved when it comes to ensure the reliability of these
systems when applied to transport vehicles. Thus, safety issues
and higher charge/discharge power rates require fundamental
research in materials science to provide more efficient electrodes
and electrolytes.

5.2.1 Li-Ion Batery Technology: Past and Present

In order to improve the performances of a Li-ion battery, one must
understand the processes involved as well as their limitations.
Generally speaking, any kind of battery is formed by a negative and
a positive electrode, also known as anode and cathode (during the
discharge phase), respectively, separated by an electrolyte. As the
processes that occur at the two electrodes are generally different, the
study of negative and positive electrodes is performed separately. In
this chapter, we shall focus on the negative electrodes.
Scrosati and coworkers [11, 12] introduced the term “rocking-
chair” batteries in 1980. In this pioneering concept, known as the first
generation of rocking-chair batteries, both electrodes intercalate
reversibly lithium and show a back-and-forth motion of the lithium
ions during cell charge and discharge. The anodic material in these
systems was a lithium insertion compound, such as Li . The

basic requirement for the rocking-chair cell was the existence of two
intercalation compounds stable within different potential ranges.
The intercalation/insertion reactions must be highly reversible
and are desired to provide sufficiently large cell voltages. Figure 5.2
shows the approximate voltage expected in the first-generation cells.
During the late 1980s, research at Sony Energytech [13]
developed the first patents and commercial products that can be
considered the advent of a second generation of rocking-chair cells.
Simultaneously, the term “lithium-ion” was used to describe the
batteries using a carbon-based material as the anode that inserts

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