A new type of partially immersed carbon gas-diffusion electrode with a sandwich-like structure consisting of two active layers each side of the gas-supplying layer is described. The current collector grid is embedded into the electrically conductive gas-supplying layer. A theoretical model of the partially immersed electrodes is proposed and experimentally confirmed. The model can be used for the theoretical prediction of the steady state behaviour of partially immersed electrodes from experimental data obtained with non-immersed gas-diffusion electrodes. An experimental zinc-air battery of 1900 A h capacity with the new type of partially immersed carbon air gas-diffusion electrodes has shown a specific energy density of 250 W h kg−1 and 420 W h 1−1 at a current density of 0·5 mA cm−2.