106results about "Molten electrolytes" patented technology

A high temperature battery of one or more cells is disclosed in which each cell is made by holding an anode electrode and a cathode electrode, of different metallic substances, together through a fused flux wetted to an electrode, which fused flux is an electrolyte, to make an anode-to-cathode contact, and the anode-to-cathode contact is heated, by a heat source, to a high temperature above a threshold temperature to generate voltaic voltage, in excess of any thermoelectric voltage; such batteries with electrodes of various configurations are disclosed. The heat-activated flux and electrolyte, such as borax, may have, vegetable-growth ashes or chemical constituents of ashes, such as lithium carbonate, added to the heat-activated flux and electrolyte to catalyze or improve the current-generating capability of the battery. The preferred anode substance is aluminum, and the preferred cathode substance is copper. With the preferred cathode and anode substances and a heat-activated flux and electrolyte of fused borax between the cathode and anode, the open circuit voltage generated per cell when heated increases from 0.05 volts at 304° C. to 1.3 volts at 651° C.; the threshold temperature in this case is 279° C. Also disclosed is means to move the anode metal with respect to the cathode metal, when the heat-activated flux and electrolyte is fluid, for changing the battery characteristics and for replacing depleted heat-activated flux and electrolyte.

Thermal batteries using molten nitrate electrolytes offer significantly higher cell voltages and marked improvements in energy and power densities over present thermal batteries. However, a major problem is gas-evolution reactions involving the molten nitrate electrolytes. This gassing problem has blocked the advantages offered by thermal batteries using molten nitrates. The solution to this gassing problem is to eliminate the chloride ion contaminates. The most important step in reducing chloride contamination is the avoidance of potassium perchlorate (KClO4) or any other chlorine-containing substances that can decompose to produce chloride ions in any thermal battery component. The Fe+KClO4 pyrotechnic used to activate thermal batteries is a key example. The decomposition of such substances into chloride ions (Cl—) results in passivating-film breakdown and gas-producing reactions with the molten nitrate electrolyte. These reactions largely involve the lithium-component of the anode used in thermal batteries such as Li—Fe (LAN), Li—Si, and Li—Al. The introduction of chloride ions into the nitrate melt via the pyrotechnic materials produces a rapid breakdown of the protective oxide film on lithium-based anodes and leads to gas-producing reactions.

A separator (3) of a molten salt battery is impregnated with a molten salt that serves as an electrolyte. The molten salt contains, as cations, at least one kind of ions selected from among quaternary ammonium ions, imidazolium ions, imidazolinium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, morpholinium ions, phosphonium ions, piperazinium ions and sulfonium ions in addition to sodium ions. These cations do not have adverse effects on a positive electrode (1). In addition, the melting point of the molten salt, which contains sodium ions and the above-mentioned cations, is significantly lower than the operating temperature of sodium-sulfur batteries, said operating temperature being 280-360 DEG C. Consequently, the molten salt battery is capable of operating at lower temperatures than sodium-sulfur batteries.