Hydroelectric Cell is a primary source of green energy device that generates electricity by dissociating/splitting water molecules on its surface. It was invented by Dr. R. K. Kotnala and Dr. Jyoti Shah in 2016 National Physical Laboratory of India, New Delhi. Dissociation/Splitting of water molecules at oxygen deficient nonporous ferrite/oxide surface creates hydronium and hydroxide ions collected by Zn and Ag electrodes respectively to generate electricity. Hence combination of nonporous oxygen deficient magnesium ferrite/metal oxide along with Zn and Ag electrodes has been coined as Hydroelectric cell. In fact, at room temperature dissociation/splitting of single water molecule requires 1.23 V potential, an external energy is required to split water molecule into its constituent ions that in general in conventional way is provided externally in the form of UV/catalysts, photons, thermal, biochemical etc. On the other hand, Nano porous surface of ferrite/oxide material provides highly reactive surface for dissociation of water molecules in to its constituent ions at room temperature which is generally available in adsorbed state. The cell's Nano porous surface provides chemidissociated H+ and OH- ions at initial stage and subsequently followed by copious physidissociation due to high electric field developed inside nanopores resulting into continuous generation of large number of ions. Zn and Ag electrodes attached on opposite surfaces of the ferrite/metal oxide pellet separate and collect opposite polarity ions result into flow of electric current in the cell. HEC is environment friendly, without producing any green house gases and its low cost raw materials are widely available as well as its disposal after its uses is non toxic. A two-inch diameter cell requires only few drops of water to develop a maximum voltage 0.98 V & a short circuit current of 120 mA. Results are highly comparable to solar cell and other portable electrical energy sources that too without use of any electrolyte/acid or alkali but requires only water. Hydroelectric cell different versions have been reported to produce green electricity using water droplets only.
Working principle
Hydroelectric Cell generates electricity by water splitting based on non-photo catalytic process and it is independent of the band gap of the material used in the cell. The cell works on the principle of water dissociation on nano-porous oxygen deficient ferrite/oxide pellet surface.The water molecules are initially chemi-dissociated at oxygen deficient nonporous surface into H+ and OH- ions and subsequently followed by continuous physi-dissociation by electrostatic field developed due to trapped H+ inside nano-pore on the pellet surface. Dissociated ions migrate towards Silver inert cathode and Zinc anode electrodes respectively and are collected via these electrodes for current generation in external circuits.In this process 0.98 V & 70 mA is generated in 4.5 sq.cm Hydroelectric cell. Zinc is consumed in this reaction and slowly converted into Zn2 and highly pure hydrogen gas is ejected. For any other electrolytic cell to work, generation of ions is essential, which is generally achieved by chemical reaction between electrolyte and electrode.Hydroelectric cell does not require any acid/alkali/electrolyte or light except water is required but only ferrite/metal oxide pellet surface acts as the continuous source of ions with water. Hydroelectric Cell working is a unique device based on the combination of material property, oxygen deficiency, Nano science and electro-chemistry.
Reaction mechanism
At Lithium substituted Magnesium Ferrite : 4H2O → 2H3O+ + 2OH− at anode : 2OH− + Zn → Zn2 + 2e− at cathode : H3O+ + H3O+ + 2e− → H2↑ + 2H2O Ecell = 0.22 - = 0.98 V Both by products of HEC are of commercial high value and the H2 gas as well as Zn2 Nano powder are biodegradable and environment friendly.
Design
Fabrication of HEC includes obtaining of ferrite material by simple heat treatment by solid state reaction technique. A small or large pellet of ferrite/metal oxide material is coated with comb patterned silver electrodes on one surface and back surface is covered with Zinc electrode. Water is sprinkled on the surface of cell while current is collected via two electrodes in an external circuit.
Performance
HEC has been reported to produce maximum 0.125 A current at 0.98 V by 2 inch diameter circular pellet. All the raw materials that are being used in cell fabrication are cheap so it is cost effective choice for electricity production as compared to other resources. Hydroelectric Cell turns chemical energy into electrical energy. In fact it is the most efficient way to produce electricity by water.
Advantages
HEC generates green energy and the residues are non toxic and its low cost component raw materials. Others are:
A HEC device is portable, compact and lightweight
It requires minimal amount of water to produce energy with no usage of hazardous chemicals
Unlike solar cell it can work during day or night and can run small scale devices like LED and fans continuously for couple of months at present which is improving further.
The two byproducts of Hydroelectric cell, Hydrogen gas and Zn2 Nano-particles are environment friendly and can be utilized for other applications.
It generates 99.9% pure H2 gas which can be used as a high quality fuel
It is a reusable device
No tedious manufacturing process is involved in making of HEC
It is very clean and safe device is to be used for electricity production and is highly reliable with acceptable performance
Usage
It can be used as a source for power generation at far/interior places like rural areas/farms, forests and mountains.
Hydroelectric Cell can be utilized for domestic and residential applications in decentralized mode to generate electricity at small scale.
After scaling up it can also be used to fulfill energy needs of automotive industry.
At a large scale HEC finds its applications in consumer products specially in rural areas.
Hydroelectric cell popularity among masses crossed over one million viewers in 18 months in YouTube besides millions of persons have watched TV News broadcast on HEC. Besides there have been lot of progress globally in past 3 years of Hydroelectric cell inception to be used in different applications.
