Aircraft battery systems and aircraft including same

Battery modules for unmanned and human piloted electric aircraft comprise two planar substrates with electrochemical cells secured between to form load-bearing structural components from which fixed-wing aircraft with greater endurance can be constructed. The cells can be oriented perpendicular or parallel to the substrates, and in the latter case the substrates can include slots that the cells fit into. The cells can be secured to the substrates by adhesives, welding, soldering and the like. Battery modules can be formed to the shapes of fixed-wing aircraft parts such as wings.