ELECTROCHEMICAL CELL

An electrochemical cell includes an electricity generator, a casing, and a terminal. The electricity generator includes a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode. The negative electrode includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer includes a first portion including a silicon layer on a surface of the negative electrode current collector and a first carbon material layer on a surface of the silicon layer, and a second portion including a second carbon material layer on the surface of the negative electrode current collector and continuous with the first carbon material layer.