Energy Storage, 2nd Edition

Chapter 6The Concentration Cell

Perhaps one of the more captivating and promising approaches to the practical storage of energy is in making use of the simple particles or billiard ball properties of matter. This view of the problem is enticing perhaps because of its direct simplicity. In other words, we might be able to make use of the straightforward “mechanical” properties of matter as described in classical molecular theory. In doing so, it appears we might be able to avoid many of the pitfalls of other energy systems that depend on specific properties of dissimilar materials (molecules), in which there are inherent mechanisms of degradation due to such issues as irreversible chemical changes, molecular diffusion from one region of the system to another, resulting in process contamination, or even just changes in molecular and physical structure that produce operational incompatibilities.

This approach does seem to offer ways around such life-limiting circumstances. In general, there is only one chemical species that participates in the energy storing process, and the processes all appear to be completely reversible by means of electrical input of appropriate polarity. If one is willing to design around or endure the peculiar electrical characteristics of such devices, perhaps a series of practical, low-cost systems can be produced in order to solve some of the more pressing energy problems we face in daily life.

We will proceed to outline some of the background physics ...