Battery assembly and method of detecting onset of thermal runaway in a battery assembly

Abstract

A battery assembly comprising a plurality of battery cells, a thermosensitive coating applied to a surface of the battery assembly, and a sensor. The thermosensitive coating is configured to emit a substance within a predetermined temperature range indicative of conditions leading to thermal runaway of the battery. The sensor is configured to detect the emitted substance. The coating may be a water-based paint comprising microcapsules of polymethyl methacrylate. The released substance may be a hydrocarbon such as an essential oil, or an ammonia emitting substance such as ammonium carbonate or urea. The predetermined temperature range may be between 50 and 120 degrees Celsius. The temperature sensitive coating may comprise two different substances which are emitted at two different temperature ranges. A thermoresponsive paint is also described.

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