Most modern RC electric helicopters use Lithium batteries. Whilst these have many advantages over older, Nickel Cadmium cells, they also have some shortcomings, not least, when it comes to safety.
Lithium batteries rely on metal oxides, typically Lithium Cobalt Dioxide (LiCoO2) to generate energy from the cathode. These chemicals have poor thermal stability, and cannot tolerate being abused. In cells that are incorrectly charged (for example, using chargers designed for different batteries) or electric helicopters that have crashed, the metal oxide becomes chemically unstable.
Although various other metals have been tried with Lithium, cobalt gives the best results. When RC electric helicopters that fly on Lithium cobalt batteries, they are flying on one of the rarest metals on earth.
The new Saphion Cells, from Valence Technology, have solved all these problems. Having spent several years searching for a safe, environmentally friendly alternative to Lithium, they have at last found the answer: a novel Olivine Lithium phosphate compound that is green, effective, and safe to use.
Olivine, is an iron rich mineral which is common everywhere, it supplies the metallic ions previously found in cobalt. Whilst the phosphate element provides the oxygen needed. The inertness of oxygenated phosphates, plus the ionic capacities of the two metals involved, provides stability with enhanced power.