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STORAGE BATTERY TECHNOLOGIES 79

Figure 3.40 Alessandro Volta’s pile.

electrochemical series, which ranks the potential produced when various metals come
in contact with an electrolyte. Figure 3.40 presents an actual photograph of the
Alessandro Volta’s battery.
A battery is an electrical energy storage device that in physics terminology can be
described as a device or mechanism that can hold kinetic or static energy for future
use. For example, a rotating flywheel can store dynamic rotational energy in the wheel,
which releases the energy when the primary mover such as a motor no longer engages
the connecting rod. Similarly, a weight held at a high elevation stores static energy
embodied in the mass of the object, which can release its static energy when it is dropped.
Both these are examples of energy storage devices, or batteries.
Energy storage devices can take a wide variety of forms, such as chemical reactors
and kinetic and thermal energy storage devices. It should be noted that each energy
storage device is referred to by a specific name; the word battery, however, is used solely
for electrochemical devices that convert chemical energy into electricity by a process
referred to as galvanic interaction. A galvanic cell is a device that consists of two elec-
trodes, referred to as the anode and the cathode, and an electrolyte solution. Batteries
consist of one or more galvanic cells.
It should be noted that a battery is an electrical storage reservoir and not an electricity-
generating device. Electric charge generation in a battery is a result of chemical interac-
tion, a process that promotes electric charge flow between the anode and the cathode in
the presence of an electrolyte. The electrogalvanic process that eventually results in deple-
tion of the anode and cathode plates is resurrected by a recharging process that can be
repeated numerous times. In general, when batteries deliver stored energy or during
charging, they incur energy losses as heat.

The Danielle cell The voltaic pile was not good for delivering currents over long
periods of time. This restriction was overcome in 1820 with the Daniell cell. British