Behavior of the calcium electrode in aqueous electrolyte. [Ca/air cell]

Conference · Sat Oct 01 04:00:00 EDT 1977

OSTI ID:5194001

Cooper, J F; Hosmer, P K

The behavior of the calcium electrode in aqueous electrolytes was investigated by using potentiostatic and galvanostatic techniques. Polarization curves and coulombic efficiency data for calcium dissolution were obtained for mixed sodium hydroxide--sodium chloride electrolytes under conditions of forced electrolyte convection. While the electrode tended to passivate in pure hydroxide solutions, the addition of the chloride ion produced a stable active state, which obeyed a linear polarization law with an electric resistivity of 30 to 300 ohm-mm/sup 2/. For mixed electrolytes, coulombic efficiency was proportional to the hydroxide concentration, approaching 100 percent near to the solubility limit (2 M NaCl, 6 to 7 M NaOH). Open circuit potentials ranged from -3.1 V (vs SCE) for low hydroxide concentrations to -1.5 V for limiting concentrations of hydroxide. Consistent with anode efficiency and polarization data and under the assumption of an air-cathode polarization of 0.4 V at 1 kA/m/sup 2/, a yield of about 35 to 40 percent energy efficiency upon discharge should be obtained for a calcium-air cell. 12 figures.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5194001
• Report Number(s): UCRL-79457; CONF-771060-3
• Country of Publication: United States
• Language: English

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25 ENERGY STORAGE
250903* -- Energy Storage-- Batteries-- Materials
Components
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ALKALI METAL COMPOUNDS
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AQUEOUS SOLUTIONS
CALCIUM
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
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GASES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN
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HYDROXIDES
KINETICS
METAL-GAS BATTERIES
METALS
MIXTURES
NONMETALS
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PASSIVATION
POLARIZATION
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SODIUM CHLORIDES
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