Li-ion Battery Information at Low Cost Batteries.com

Lithium is the lightest of all metals, has the greatest electrochemical potential, and provides the largest energy content. Rechargeable batteries using lithium metal as an electrode are capable of providing both high voltage and excellent capacity, resulting in an extraordinary energy density.

After much research during the eighties, it was found that occasional shorts from lithium dendrites could cause thermal run-away. The cell temperature quickly approaches the melting temperature of lithium which results in violent reactions. A large quantity of rechargeable lithium batteries sent to Japan had to be recalled in 1991 after a battery in a cellular phone exploded and inflicted burns to a man's face.

Because of the inherent instability of lithium metal, especially during charging, research shifted to a non-metallic lithium battery using lithium ions from chemicals such as Lithium-Cobalt Dioxide (LiCoO₂). Although slightly lower in energy density than with lithium metal, the Li-ion is safe, provided certain precautions are met when charging and discharging. In 1991, Sony commercialized the Li-ion and is presently the largest supplier of this type of battery.

Distinct advantages of today's Li-ion batteries are:

The energy density of the Li-ion is at least twice that of the NICAD and its load current rating is reasonably high. In fact, the Li-ion behaves similarly to the NICAD in terms of discharge characteristics. In addition, the Li-ion has a relatively low self-discharge.

No memory effect

500 to 800 charging cycles

Negative attributes of today's NiMH batteries are:

Susceptible to damage from overcharge and over discharge.

Charging: Only use battery chargers especially designed for the Li-ion battery.