Electrochemical heating device

A shelf-stable electrochemical heating blanket capable of generating heat at a controlled rate comprising a flexible envelope adapted to be wrapped around an article so as to transfer heat developed within the envelope to the article, and disposed within the envelope, 100 mole-parts of thin metal chips having surface dimensions between about 0.1 and 1 centimeter and selected from magnesium and aluminum;

• a water-soluble salt present in an amount sufficient to provide a solution having a conductivity of at least 0.05 mho/centimeter pg,18 when dissolved in 500 mole-parts of water;
• at least 0.25 mole-part of a plating salt that provides metal ions adapted to react with said metal anode chips in said conductive solution to form a coating of metal on the chips that serves as the cathode of an electrochemical cell;
• and a porous inert flexible structure disposed inside the blanket in a weight amount equal to at least 10 percent of the weight of the metal anode chips;
• at least 60 percent of the heat obtainable from the blanket after activation by mixing said ingredients and enveloping the metal chips in conductive solution being produced through electrochemical reactions including reduction of water to hydroxyl ions and hydrogen gas at the cathode and oxidation of the anode metal chips.