Carnot is almost two centuries old and only covers heat engines.
With the increasing interest in fuel cells it would be nice to have something that covers fuel cells as well as heat engines.
The similarities in processes as well as results between low pressure ratio highly recuperated gas turbines and fuel cells suggests that this may be possible:
LPR Gas Turbine: theoretical efficiency over 80%
Fuel cell: theoretical efficiency over 80%
LPRGT: even higher efficiency with ceramics that rapidly degrade
FC: even higher efficiency with materials that rapidly degrade
LPRGT: heat transfer
FC: mass transfer
LPRGT: big expensive heat exchanger area for heat transfer
FC: expensive contact area for mass transfer