Technologies
See the menu at left for discussions of individual storage technologies.
Li-ion Batteries
Description:
The cathode in these batteries is a lithiated metal oxide (LiCoO2, LiMO2, etc.) and the anode is made of graphitic carbon with a layer structure. The electrolyte is made up of lithium salts (such as LiPF6) dissolved in organic carbonates.
When the battery is being charged, the Lithium atoms in the cathode become ions and migrate through the electrolyte toward the carbon anode where the combine with external electrons and are deposited between carbon layers as lithium atoms. This process is reversed during discharge.
The main advantages of Li-ion batteries, compared to other advanced batteries, are:
- High energy density (300 - 400 kWh/m3, 130 kWh/ton)
- High efficiency (near 100%)
- Long cycle life (3,000 cycles @ 80% depth of discharge)
Deployment Status:
While Li-ion batteries took over 50% of small portable market in a few years, there are some challenges for making large-scale Li-ion batteries. The main hurdle is the high cost (above $600/kWh) due to special packaging and internal overcharge protection circuits.
Several companies are working to reduce the manufacturing cost of Li-ion batteries to capture large energy markets (multi-kW, kWh sizes for residential & commercial markets). The auto industry is the driver behind this development.
Developers / Suppliers:
SAFT
HITACHI