The lead–acid battery is one of the most popular secondary batteries because of its wide usable temperature range, reasonable cost, relatively high discharge capacity, etc. To prevent short-circuits across the separators due to the formation of metallic lead dendrites, alkaline sulfate or alkaline earth sulfate is sometimes added to the electrolyte. There have been reports, however, that some alkaline sulfates, such as sodium sulfate (Na2SO4), decrease the charge-acceptance capability. This presentation discusses investigations of the electrochemical behaviour of a lead electrode, which corresponds to the negative electrode of a lead–acid battery, in sulfuric acid solution with various alkaline sulfates namely, Na2SO4, K2SO4, Li2SO4, Rb2SO4, or Cs2SO4,. The effect of sodium ions in the electrolyte solution on strap corrosion and charge-acceptance of the lead–acid battery from a fundamental viewpoint by using various analytical techniques that include EC-AFM (electrochemical atomic force microscopy) and FIB-SEM-EDX (focused ion beam-scanning electron microscope-energy dispersive X-ray spectroscopy). Proposals are given on how to minimize strap corrosion and maintain charge-acceptance.
National Institute of Technology, Suzuka College
Biography: Dr. Nobumitsu Hirai is an associate professor in the Department of Chemistry and Biochemistry at the National Institute of Technology, Suzuka College, Japan. He received a Bachelor of Engineering from Kyoto University in 1992, a Master of Engineering from Kyoto University in 1994, and a PhD from Osaka University in 2000. He is the author 5 books, 49 refereed papers, and many conference proceedings papers. He is the recipient of an Encouragement Prize from The Japan Institute of Metal and Materials in 2001, and an Encouragement Prize from the Molten Salts Committee of The Electrochemical Society of Japan in 2005.