LiCoO2 Battery Technical Features

The first commercially available Li-ion cobalt oxide cells were introduced in 1991 by Sony at the height of the portable electronics industry boom. Today, it is difficult to imagine life without this technology and without the hundreds of millions of portable electronic devices they power. Without Li-Ion cobalt oxide the portable electronic devices we know today would be heavy and bulky and many would not exist at all. Tablets, bluetooth headsets, thin client notebooks and smart phones would not exist if it had not been for invention and development of this technology.

Commonly known as 'high energy' cells, LiIon LiCo2 cells use a metal oxide cathode of lithiated metal oxide (LMO) and offer among the highest energy density figures, by weight or volume, of the commercially available Li-ion families. Other metal oxide cathodes have been developed, but none have seen the commercial adoption of the LiCo2 cathode.

Typical Li-ion cells with metal oxide cathodes operate at a nominal voltage of between 3.6 and 3.8 volts and have an operating range of between 4.2V to 3.0V. Metal oxide-based cathode materials are prone to decomposition if operated outside of strict specifications. When the cathode decomposes, it releases oxygen into the cell, which can, depending on other circumstances can lead to a thermal destabilization of the cell (sometimes called thermal runaway). Each cathode material, when matched to a compatible anode material, will exhibit various performance attributes that can be used to categorize and differentiate cells in this family. Batteries comprising of these cells must be fitted with battery management systems to ensure that cell voltages and currents do not exceed set boundries.

Development is very active in this segment and focuses on providing higher energy densities, better cycle life performance, lower internal impedance (decreasing heat generated on discharge), better power performance, and better thermal stability.

1. High energy density (both volumetric and gravimetrtic)

2. Large number of mechanical cell sizes available

3. High voltage - a single cell replaces three NiCd or NiMH cells

4. Active development - significant investment into further improvements

5. No memory effect

6. Very low rate of self discharge

1. Fast moving technology means that products are replaced regularly

2. Protection circuits required to prevent overcharge and over discharge

3. Moderate discharge capability make the technology unsuitable for high power applications

4. Performance at low temperatures can be poor due to higher internal resistance

5. Limited cycle life (300-500 cycles)

6. Transportation regulations require cells and batteries to be tested

The market for Lithium ion (LiCoO2) is huge - with nearly all portable consumer electronic devices using the technology due to its high energy density, moderate discharge capability and good safety.