Rechargeable alkali metal-halogen cell with liquid electrolyte - having separator of uniform beta:alumina crystals, avoiding high self-discharge rate

摘要

Rechargeable galvanic cell has a negative electrode of alkali metal, pref. Na, which is solid at the operating temp. a positive electrode of chlorine or bromine, pref. chlorine, and an electrolyte of Al chloride, alkali chloride or bromide, pref. NaCl, and sulphur dioxide which is liquid at the operating temp. Improvement is the use of a separator of beta-alumina of uniform crystal size. Pref. the separator consists of Na-Beta-alumina on a porous support. It contains a stabilising additive, pref. Li or Mg oxide. The cell avoids high self-discharge rate.