Historically, 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.
1. High Energy Density
The weight of a lithium polymer 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.
2. 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.
The lithium polymer battery does not contain any polluting substances such as cadmium, lead, mercury, etc.
4. Non-metal Lithium
The lithium polymer battery does not employ any lithium metal. It is not governed by aircraft transportation rules relating to carrying lithium batteries in passenger airplanes.
5. Long Cycle Life
Under normal conditions, the lithium ion battery has a life of more than 500 charge/discharge cycles.
6. 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.
7. Fast Charge CapacityApplications
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.
The rechargeable lithium polymer 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