text: Alkaline batteries use manganese dioxide and zinc electrodes with an electrolyte of potassium hydroxide. The alkaline battery gets its name from the replacement of the acidic ammonium chloride of zinc–carbon batteries with potassium hydroxide, which is an alkaline. Alkaline batteries are considerably more efficient, more environmentally friendly, and more shelf-stable than zinc–carbon batteries—five to ten years, when stored room temperature. Alkaline batteries largely replaced zinc–carbon batteries in regular use by 1990.
  After an alkaline battery has been spent, or as it reaches the ends of its shelf life, the chemistry of its cells change, and hydrogen gas is generated as a byproduct. When enough pressure has been built up internally, the casing splits at the bases or side (or both), releasing	manganese oxide, zinc oxide, potassium hydroxide, zinc hydroxide, and manganese hydroxide.
  Alkaline battery leakage can be effectively neutralized with lemon juice or distilled white vinegar. Eye protection and rubber gloves should be worn, as the potassium hydroxide electrolyte is caustic.