ELECTROCHEMICAL CELL AND ELECTROCHEMICAL CELL STACK

An electrochemical cell includes a power-generating element including a semi-solid positive electrode, a semi-solid negative electrode, a separator located between the semi-solid positive electrode and the semi-solid negative electrode, a positive-electrode current collector electrically connected to the semi-solid positive electrode, and a negative-electrode current collector electrically connected to the semi-solid negative electrode; and a packaging body which encases the power-generating element, the packaging body including single or plural holes which open on an inner side of the packaging body and an outer side of the packaging body.