▎ 摘　　要

NOVELTY - Electrochemical device comprises a first electrode assembly and a second electrode assembly set in a shell. A clapboard is set between the first electrode assembly and the second electrode assembly and divides the shell into a first cavity and a second cavity separated from each other. The clapboard comprises a barrier layer surface set with a phase change layer comprises phase change material comprising at least one of alkane wax, polyethylene wax, polyethylene glycol and/or fatty acid. The barrier layer comprises at least one of metal, polymer and/or carbon material. USE - The electrochemical device is useful in electric device (claimed). ADVANTAGE - The electrochemical device: has phase change layer in the clapboard with heat absorption and heat storage function thus cools area between the electrode assembly and reduces the performance degradation caused by local overheating and the risk of safety; and improves the electrochemical performance and safety performance. DESCRIPTION OF DRAWING(S) - The drawing shows a structure schematic diagram of the electrochemical device.