The objective of this project is the replacement of environmental harmful Nickel Cadmium (NiCd) batteries by  Nickel metal hydride (NiMH) batteries, also for high-current applications. This objective is aligned with EU legislation started to ban the heavy metals like Cadmium from the batteries. The new directive will enter into force from 2006 tentative. This directive puts a ban on Cd-containing batteries except of batteries for power tools and emergency lightings. The reason for this exemption is the lower rate capability of NiMH batteries.

Since years the environment friendly NiMH rechargeables are used in all kinds of portable devices as well as the rechargeable Li-Ion cells. With both technologies the attainable current densities are not sufficient for the use in devices with higher current consumption. This prohibits the replacement of NiCd batteries in nearly all market segments they are still in use. The capability of NiMH batteries can be enhanced drastically in improving the surface/volume-relation of the cell. This can be realized by reduction of the particle sizes from a few hundred µm into the range of nanometers. However, the high surface energy of such extremely small NiMH particles leads to a pyrophoric behavior which is extremely hazardous and very difficult to handle in production process.

To overcome these constraints the NiMH particles will be nanocoated in this project in order to advance the capability to function as an enhanced proton conductor during battery operation and on the other hand to reduce the extremely high reactivity when producing the cell. This should be achieved in using intrinsic proton conductors or in the utilization of hydrophobic insulation materials. Under the strong alkaline conditions within the cell the nanocoating will become gel-like because of processes of partly dissolving resulting in an improved ion conductivity of the nano-coating. Thus, the coating will not only improve the safety during the battery production but will also lead to an increase of the performance of the battery itself. Batteries with nanocoated NiMH particles and their performance will be demonstrated at the end of the project.