**1. Introduction**

The growing concern over the environment on a global basis is driving extensive research into new materials for next generation of clean, efficient, alternative energy systems, to a large extent based on various types of electrochemical cells. An especially useful method that has paved the way to novel materials with unique properties, which cannot be fabricated by other methods, is the cold plasma technology. Both integrally new materials in the form of thin films with unusual molecular structure and conventional materials modified by cold plasma, which reveal surprising surface properties, can be prepared in this way. Some of these materials turned out to be very interesting for the innovative electrochemical cells.

In this Chapter, a brief review of investigations performed on materials produced by the cold plasma technology and their testing in electrochemical cells, such as fuel cells, rechargeable cells and related devices as solar cells and water splitting systems, is presented. Some attention is paid to research conducted in our laboratory.1 Recent results of our studies on plasma deposited thin films of nanocatalysts based on metal oxides, such as cobalt and cupper oxides, which have been tested as electrodes for fuel cells, are discussed in more detail. Our efforts directed towards the development of new materials for solar cells and water splitting systems are also mentioned. However, before turning to the details of these issues, we should first familiarize ourselves, even cursory, with the cold plasma technology.
