Polymer
Li-ion & Li-ion
Overview
istorically, lead-acid, nickel-cadmium (Ni-Cd), and nickel-metal
hydride (Ni-MH) batteries have been the conventional
choice for small-sized rechargeable batteries.
In line with the recent trends toward mobile
and cordless electronic equipment, rechargeable
batteries are required to provide higher energy
density to meet the needs of ever smaller
and lighter devices. Moreover, the attention
being focused on protecting the environment
has resulted in demand for products that are
environmentally friendly.
Features
A. High Energy Density
The weight of a lithium ion battery is approximately
one half compared to a nickel-cadmium or nickel-metal
hydride battery of similar capacity. Moreover,
the volume of the lithium ion battery is 40
to 50% smaller than that of a nickel-cadmium
and 20 to 30% smaller than that of a nickel-metal
hydride battery.
B. High
Voltage
A single lithium ion cell has a voltage
of 3.7V ( mean value), which is equal to
either three nickel-cadmium or nickel-metal
hydride cells connected in series.
C. Pollution-free
The lithium ion battery does not contain
any polluting substances such as cadmium,
lead, mercury, etc.
D. Non-metal
Lithium
The lithium ion battery does not employ
any lithium metal. It is not governed by
aircraft transportation rules relating to
carrying lithium batteries in passenger
airplanes.
E. Long
Cycle Life
Under normal conditions, the lithium ion
battery has a life of more than 500 charge/discharge
cycles.
F. No
Memory Effect
The lithium ion battery is free from the
so-called memory effect, a phenomenon seen
in nickel-cadmium in which the apparent
battery capacity decreases when shallow
charge and discharge cycles are repeated.
G. Fast
Charge Capacity
The lithium ion battery can be fully charged
in 1 to 2 hours, using a constant-current
/ constant-voltage (CC/CV) type dedicated
charger with a rated voltage of 4.2V per
cell.
Specifications
of Prismatic cell & Cylindrical cell
Applications
The rechargeable
lithium ion battery shows great promise
as a battery to meet such requirement. This
new battery technology has excellent features,
such as: high energy density, high voltage,
good storage and cycle life characteristics.
These batteries are widely used for 3C applications
such as: Personal Computers, Cellular Phones,
and for personal cordless electronic applications
i.e. Portable CD Players, PDA etc
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