The present disclosure provides a cell and an electrochemical device. The cell comprises: a first electrode plate comprising a first current collector and a first active material layer, a second electrode plate comprising a second current collector and a second active material layer; a first electrode tab, a second electrode tab, a separator. The first current collector has a first surface uncoated region; the second current collector has a second surface uncoated region; the first electrode tab is provided on the first surface uncoated region, the second electrode tab is provided on the second surface uncoated region. The first electrode tab and/or the second electrode tab are enlarged in length and width. When the cell is subjected to a mechanical shock, the first electrode tab and the second electrode tab are deformed to puncture the separator therebetween, so the first current collector and the second current collector are electrically connected.