Standard NiMH Cells - Datasheets
As
electronic products have come to feature more sophisticated
functions, more compact sizes and lighter weights, the sources
of power that operate these products have been required to
deliver increasingly higher levels of energy. To meet this requirement, nickel-metal hydride batteries have
been developed and manufactured with nickel hydroxide for the
positive electrode and hydrogen-absorbing alloys, capable of absorbing
and releasing hydrogen at high-density levels, for the negative
electrode.
Because Ni-MH batteries have about twice the energy density of
Ni-Cd batteries and a similar operating voltage as that of Ni-Cd
batteries, they are expected to become a mainstay in the next generation
of rechargeable batteries.
Construction
Nickel-metal hydride batteries consist of a positive plate containing
nickel hydroxide as its principal active material, a negative
plate mainly composed of hydrogen-absorbing alloys, a separator made
of fine fibers, an alkaline electrolyte, a metal case and a sealing
plate provided with a self-resealing safety vent. Their basic structure
is identical to that of Ni-Cd batteries. With cylindrical nickel-metal
hydride batteries, the positive and negative plates are separated
by the separator, wound into a coil, inserted into the case,
and
sealed by the sealing plate through an electrically insulated
gasket.
|