Fuel cartridge and fuel cell using the same

A fuel cartridge, comprising:

• a flexible container that does not have an outer rigid fuel container, the flexible container comprising two sides formed of a single layered material adhered to each other at edges to define an inner space configured to store a liquid fuel;
• a connector fluidly connected to one of the sides of the flexible container, the connector comprising an opening configured to discharge the liquid fuel;
• and
• a channel-forming structure formed with a substantially linear shape and disposed only inside the inner space of the flexible container, at least a portion of which is disposed proximal to the connector and substantially parallel to the one side of the flexible container,
• wherein the channel-forming structure is configured to provide a flow field interconnecting the inner space with the opening of the connector, thereby permitting the discharge of the liquid fuel from the flexible container when the two sides of the flexible container near the connector are in contact with each other,
• wherein the channel-forming structure comprises a wrinkle part comprising a single-layered fold in the one side of the flexible container, and
• wherein the wrinkle part is more rigid than the one side of the flexible container.