Mike has been working on the SMD cell for quite a while, and he’s now ready to go public with the results. At base, this is a way to turn Iron (or some other metal) and electricity (from solar power or other intermittent source) into Hydrogen gas as a storage medium. The big advantage of the process is that it produces no Oxygen from electrolysis (which is normally an unwanted by-product) but instead oxidises the sacrificial metal with it and gains more Hydrogen as a result. The Hydrogen can then be used later to either produce heat or electrical power when needed. He’s working on developments of the basic idea that may be better-suited to running an electric vehicle.
Most of the rest of this article will be Mike’s own descriptions:
The SMD hydrogen cell uses three electrodes, it works as an energy and a hydrogen producer depending on the cycling mode. One is the hydrogen electrode and is made of stainless steel, this is formed as a cylinder and has the biggest diameter, it is the only electrode which produces hydrogen.
The second electrode is the oxygen electrode which is made of nickel hydroxide and carbon pressed on to a nickel plated foil for good contact and electrical conduction. This is formed into a cylinder of smaller diameter than the hydrogen electrode and is contained within a fine mesh (Fig:3), the surface area is far greater than the hydrogen electrode. In the centre of the cylindrical cell is the third electrode, this is made of iron and is the sacrificial electrode in this cell.
It can be seen that this is in part a nickel iron battery, the difference here is it is not charged in a conventional way, and produces hydrogen with reduced input power. The battery side to this cell is charged by the absorption of oxygen creating nickel oxy-hydroxide (NiOOH) at the second electrode, this is a very fast charge, while at the same time as creating pure hydrogen on the outer electrode. The power for this comes from a super capacitor store bank which is charged on one cycle by the external solar, wind or off peak grid in series with the internal battery power generated by the Ni/Fe reaction within the cell. The iron electrode on discharge is oxidised to iron hydroxides, and in this case is a one way reaction as recharging is rapidly done by the oxidation of the nickel electrode.
As can be seen, the oxygen, which is not wanted, is put to use to generate electrical power. Over 30% of the power for creating hydrogen from water, can come from the chemical reaction of the unwanted oxygen, and all in the same cell through creative design. In practical systems these cells are linked in series and or parallel to gain the working power and hydrogen production required, there is no real limit to the number. The external power can be a fluctuating supply as in wind or solar, there is no start up or run down time required, and the resulting hydrogen can be stored or converted to SNG (methane) using the Sabatier reaction.
This system is ideal for power to gas, be it on or off grid, and has the smallest power to gas loss of any electrolysis system today producing hydrogen from water.