Hughes Aircraft Company

Richard P Sernka

Steven J Stadnick

Howard H Rogers

Robert K Taenaka

Improved nickel-hydrogen batteries (10) are disclosed, wherein the improvement provides for wettable porous polypropylene cloth gas diffusion screens (12) to separate the individual cells (16) thereof. When necessary, substantially all of the electrolyte may be readily drained from the cells (16) of the batteries (10). Wettability is achieved by oxidizing the surfaces of the cloth gas diffusion screens (12) prior to assembling them in the batteries (10).

Nickel-hydrogen cells

A sodium-sulfur electrical storage cell (10) has a planar solid electrolyte (16) that is permeable to sodium ions, a planar permeable porous cathode (24) filled with sulfur, a planar permeable porous anode (28) filled with sodium, and an electrically nonconducting, closed flat container (12) for these elements. The electrolyte (16) is thin and strengthened, as by an integral supporting structure (22), or supported, as by a structural anode core structure (36) or by cross members (22) of the container, to minimize its deformation during operation. The anode (28) and cathode (24) are electrically conducting even without sodium and sulfur present, so that the cell (10) fails to a shorted state.

Planar sodium-sulfur electrical storage cell

A sodium sulfur electrical storage cell includes means for avoiding bubbles in the sulfur cathode during operation in a weightless environment. Formation of bubbles of sulfur or other gas in the cathode is prevented by pressurizing the sulfur cathode to a pressure greater than the vapor pressure of the sulfur at the operating temperature, typically about 350 C. The applied pressure is preferably supplied by a chemical compound, such as sodium azide, that is placed into the chamber holding the sulfur. At the operating temperature of the cell, the compound decomposes to produce a gas, nitrogen in the case of the sodium azide, that is substantially insoluble in the sulfur yet produces a sufficiently high pressure over the liquid sulfur that bubbles of gaseous sulfur or other gases cannot form in the sulfur. If bubbles were permitted to form in a weightless environment, they would migrate to a location where they would interfere with the operation of the cell.

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Long Beach, CA, United States of America

Richard P Sernka