article_snippet.sent: Smartphones often overheat if Smartphones're held close to the body or are used for long periods of time.
article_snippet.sent: This occurs when the rate of heat generated in one cell is greater than the rate of heat lost.
article_snippet.sent: Lithium-ion cells with cobalt cathodes, for example, are not designed to rise above 130°C (265°F).
article_snippet.sent: This is because, at 150°C (302°F) the cell becomes 'thermally unstable'.
article_snippet.sent: Once the cell reaches this state this state can lead to a thermal runaway in which flaming gases are released.
article_snippet.sent: During a thermal runaway, the high heat in the failing cell can travel to the next cell, causing the next cell to become thermally unstable as well.
article_snippet.sent: In a real-world situation this could have increased thermal runaway because this allows oxygen into the cell.
article_snippet.sent: During a thermal runaway, the high heat in the failing cell can travel to the next cell, causing the next cell to become thermally unstable as well.
article_snippet.sent: The authors found that thermal and electrochemical reactions inside both cells produced gas pockets that deformed the spiral wound layers of the cells.