[azalemeth]

The classic example of a good military-only battery would be those using molten salts as an electrolyte (typically at 150-500 ºC) [1]. Very high energy density (around 74 Ahr/kg [2] compared to LiPo's ~50 Ahr/kg [3]) and very high power density. Not finger friendly.

[1] http://en.wikipedia.org/wiki/Molten_salt_battery [2] https://global-sei.com/technology/tr/bn76/pdf/76-06.pdf [3] https://blog.ampow.com/lipo-battery-size-chart/

[Someone]

If one could make such a battery small enough for this drone, I expect you would need all its power to keep the salt molten.