An electrochemical cell that comprises a single positive electrode , a single negative electrode , a separator that is disposed between the positive electrode and the negative electrode , wherein the positive electrode , the negative electrode and the separator are arranged in a stacked configuration, an electrically-insulating frame disposed between portions of the positive electrode and the negative electrode so as to isolate the positive electrode and the negative electrode , the frame having an inner peripheral edge that surrounds the separator and an outer peripheral edge , and a sealing material layer residing between the positive electrode and the negative electrode , the sealing material layer including a first sealing portion and a second sealing portion , the first sealing portion disposed between the frame and an inward facing side of the positive electrode , and the second sealing portion disposed between the frame and an inward facing side of the negative electrode , wherein the frame is secured relative to the positive electrode and the negative electrode by the sealing material layer , characterized in that the outer peripheral edge of the frame protrudes outward relative to a peripheral edge of the positive electrode and the negative electrode , and the inner peripheral edge of the frame is sandwiched between the first sealing portion of the sealing material layer and the second sealing portion of the sealing material layer , whereby a seal exists between a positive electrode inward facing side of the positive electrode and the frame , and also between a negative electrode inward facing side of the negative electrode and the frame . a single positive electrode , a single negative electrode , a separator that is disposed between the positive electrode and the negative electrode , wherein the positive electrode , the negative electrode and the separator are arranged in a stacked configuration, an electrically-insulating frame disposed between portions of the positive electrode and the negative electrode so as to isolate the positive electrode and the negative electrode , the frame having an inner peripheral edge that surrounds the separator and an outer peripheral edge , and a sealing material layer residing between the positive electrode and the negative electrode , the sealing material layer including a first sealing portion and a second sealing portion , the first sealing portion disposed between the frame and an inward facing side of the positive electrode , and the second sealing portion disposed between the frame and an inward facing side of the negative electrode , wherein the frame is secured relative to the positive electrode and the negative electrode by the sealing material layer , characterized in that the outer peripheral edge of the frame protrudes outward relative to a peripheral edge of the positive electrode and the negative electrode , and the inner peripheral edge of the frame is sandwiched between the first sealing portion of the sealing material layer and the second sealing portion of the sealing material layer , whereby a seal exists between a positive electrode inward facing side of the positive electrode and the frame , and also between a negative electrode inward facing side of the negative electrode and the frame . <EOS>