Engines are good to go, better power density than pistons and probably turbines. Probably better reliability when built to appropriate standards.

Batteries can be reliable, compact, or cheap...pick one or maybe two at best.

I'm sure you could make a lithium battery/electric motor combo which would far exceed the reliability of current propulsion systems. But it would be very expensive.

For example I suspect that lithium batteries need a temperature and pressure controlled environment...basically the battery needs is own pressure container with thermal controls. They also probably need extreme quality control in design and construction, and probably active vibration damping. On top of that you need containment that can withstand a full runway, and at least two parallel units for redundancy. It can be done, but it won't be cheap, or very compact/light.