Caustic battery electrolyte

Schumacher, E.A. Chapter 3, Primary cells with caustic alkali electrolyte. In The Primary Battery, Heise, G.W., Cahoon, N.C., Eds. Wiley New York, 1971 Vol. 1, 169. 

Potassium hydroxide is used to make soft soap, in scrubbing and cleaning operations, as a mordant for woods, in dyes and colorants, and for absorbing carbon dioxide. Other principle uses of caustic potash are in the preparation of several potassium salts, acid-base titrations, and in orgainic sytheses. Also, KOH is an electrolyte in certain alkaline storage batteries and fuel cells. 

Rubidium hydroxide is used as a catalyst in oxidative chlorination. It also may be used as a powerful base, stronger than caustic potash, in many preparative reactions. The compound holds promising apphcations as an electrolyte in storage batteries for use at low temperatures. 

The desalination of brackish water by electrodialysis and the electrolytic production of chlorine and caustic soda are the two most popular processes using ion-exchange membranes. There are, however, many other processes such as diffusion dialysis, Donnan dialysis, electrodialytic water dissociation, etc. which are rapidly gaining commercial and technical relevance. Furthermore ion-exchange membranes are vital elements in many energy storage and conversion systems such as batteries and fuel cells. 

Union Carbide Corp. (UCC) developed AFCs for terrestrial mobile applications starting in the late 1950s, lasting until the early 1970s. UCC systems used liquid caustic electrolytes the electrodes were either pitch-bonded carbon plates or plastic-bonded carbon electrodes with a nickel current collector. UCC also built fuel cell systems for the U.S. Army and the U.S. Navy, an alkaline direct hydrazine powered motorcycle, and the Electrovan of General Motors. Finally, Professor Karl V. Kordesch built his Austin A-40 car, fitted with UCC fuel cells with lead acid batteries as hybrid. It was demonstrated on public roads for three years. The years of research and development are very well summarized in reference (5) Brennstofflyatterien. 

The Ni-Cd accumulator uses a cadmium negative electrode and a nickel-hydroxide (NiOOH) positive electrode, which is reduced into nickel hydroxide (Ni(OH)2) during the discharge of the battery. The electrolyte is an aqueous alkaline solution - potassium hydroxide (KOH) or caustic soda (sodium hydroxide, NaOH), and may or may not contain additional lithium hydroxide (LiOH, also known as lithine). 

Protective measures against corrosive and caustic effects of the electrolyte, e.g. sulfuric acid (H2SO4) in lead-acid batteries and potassium hydroxide (KOH) in NiCd batteries. 

Alkaline batteries are the most ideal option for a simple embedded-system application. This battery can be fabricated using Zn for the anode (negative electrode), MnOj for the cathode (positive electrode), and Zn powder with a caustic alkali of KOH for the electrolyte. This particular battery offers long shelf life, supports... 

Water-activated cells and batteries are supplied sealed. The caustic (potassium hydroxide) electrolyte and the lime flake are present in Ae dry form. The cell is activated by removing the seals and adding the appropriate amount of water to dissolve the potassium hydroxide. Periodic inspection and addition of water are the only required maintenance. 

This corrosion of the anode, in an alkaline electrolyte, is one of the factors that reduce the cou-lombic efficiency and the energy density of the Al-air cell. Several methods have been developed to decrease this corrosion. Aluminum alloys have been used to decrease the corrosion, as have corrosion inhibitors that are added to the caustic electrolyte. Non-caustic electrolyte, such as salt water (saline solution), are also used to decrease the corrosion of the aluminum anode. The alkaline electrolyte system has the advantage of higher conductivity over the salt water system, which results in a high discharge rate for the battery. 

Most battery systems in which lithium is apphed as anode material belong to the group using nonaqueous electrolytes, but there is one system that works with water serving as solvent and reactant as weU. This is only possible because hthium forms a passive layer in solutions containing higher amounts of caustic [104-107]. 

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