The electronic ignition on my grill no longer

Yes you can replace the entire assembly.
However you can try adjusting the spark gap to see if this will resolve the issue.
Heat will often expand the spark gap thus rendering a spark impossible.
Small adjustments and be careful not to break the ceramic insulator.

Many gas grills use a static ignitor that does not require a battery.
Big red button you push that causes a snapping noise. This makes a spark and lights the gas. These can last quite a long time and inexpensive too.

Good luck!