1. Field of the Invention
This invention relates to rechargeable stored energy systems, specifically to:
a Improvements in specific energy density for a reversible cell.
b Improvements in specific power density delivered from a reversible cell.
c Improvements in cell cost for a given energy density.
2. Description of the Related Art
A detailed patent search was carried out covering over 500 individual patent searches including cross references. The research found electrically charged battery systems with electrical output. Their was no mention of an electrically rechargeable system with a thermal discharge output in combination.
Search categories included: 429.149, 136.200, 136.202, 429, 429.17, 204.248, 429.19, 429.247, 136.224, 320, 431.80, 432.30, 429.12, 136.203.
The systems were either pure electric, i.e. charge and discharge, or pure thermal. There was mention of systems which started with heat and converted it to electricity.
The current invention provides a unique combination of electrical charging with a thermal discharge. The system is a fully reversible closed system.
The electro-chemical-thermal cell is a unique combination which has significant advantages in terms of energy and power density over existing electrical or thermal storage cells. The system charges electrically storing the bulk of the energy in chemical form. This allows indefinite storage capabilities with full power on restart. The thermal output design focuses the heat into a small high temperature region. This provides the maximum efficiency to thermal power conversion systems such as Stirling, Brayton, or Rankine cycles.
The ECT cell is unique in the use of a salt control valve which maintains a local low temperature eutectic salt mixture around the electrodes. This allows higher energy densities in the cell by reducing the quantities of eutectic salts. The valve functions by regulating a dry powdered Sodium Chloride into the eutectic bath at a rate determined by the electrolysis of the Sodium Chloride in the eutectic bath.
The ECT cell is also unique in its ability to operate as a single cell independent of the number of electrodes used. A technique is used to electrically isolate each electrode within the salt bath so as to prevent shorting from the liquid metal formed during electrolysis.
The ECT cell is also unique in the use of a Boron Carbide xe2x80x98valve electrodexe2x80x99 layer made from a porous graphite starting material.