▎ 摘　　要

NOVELTY - The device has an electrode pole piece comprising a current collector. An active material layer is arranged on a side of the current collector. A coating is arranged between the current collector and the active material layer, where the coating comprises copolymer, the copolymer has thermal expansion rate less than 1 % at 100 degrees centigrade, the copolymer has thermal expansion rate greater than 15 % at 130 degrees centigrade, and weight average molecular weight of the copolymer is from 20-150 million. The copolymer comprises a first structural unit derived from monomer and a second structural unit derived from another monomer, where the first monomer comprises acrylic acid, acrylonitrile, acrylamide and vinyl acetate, and the second monomer comprises vinylidene fluoride, methyl methacrylate and styrene. A conductive agent comprises conductive carbon black, acetylene black, graphite graphene carbon nano-tube, carbon fiber, aluminium powder, nickel powder and gold powder. USE - Electrochemical device for use in an electronic device (claimed). Uses include but are not limited to notebook computer, pen input type computer, mobile computer, electronic book player, portable telephone, portable fax machine, portable copier, portable printer, head stereo headphone and video recorder. ADVANTAGE - The device has excellent thermal safety under condition of heat abuse, and has high safety performance and multiplying power performance. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of an electrode pole piece of an electrochemical device 1Active material layer 2Coating 3Current collector