How does this compare to the efficiencies of batteries and gasoline engines? I know otto cycle engines are limited to low 10s% efficiency for just the car as a

How does this compare to the efficiencies of batteries and gasoline engines? I know otto cycle engines are limited to low 10s% efficiency for just the car as a system as a whole. I haven't seen much about the efficiency in terms of "round-trip" which would be interesting to compare to fuel cells.