▎ 摘　　要

NOVELTY - Electrochemical device has a housing to accomodate a battery cell. The cell has a first pole piece (100), a second pole piece and a diaphragm. The first and second pole piece are arranged in a winding manner, and the diaphragm is located between the first and second pole piece. The first piece has: a current collector (110) having a first surface facing an interior of the cell and a second surface facing away from the interior of the cell; a tab (120) electrically connected with the collector and extends out of the collector; a first active material layer (130) disposed on the first surface; and a second active material layer arranged on the second surface. The first active material layer has a main body coating (131) and an edge coating (132). The edge coating is positioned on one side of the main body coating facing the tab and is adjacent to or partially overlapped with the main body coating along a first direction. USE - Electrochemical device used to supply power to an electronic device (claimed). ADVANTAGE - The electrochemical device has high energy density and good electric performance. The edge of the main body coating of the active material layer is provided with an edge coating. The external expansion material layer in the slurry state in the pole piece edge area is reduced, and the thickness of the edge area of the electrode material layer is increased, so as to improve the energy density of the device. The multilayer pole pieces are stacked more closely in the edge region, thus reducing the ion transmission path and reducing the possibility of lithium evolution. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the structure of a first pole piece of the electrochemical device. (Drawing includes non-English language text) First pole piece (100) Current collector (110) Tab (120) First active material layer (130) Main body coating (131) Edge coating (132)