Dear Raghunathan,

I don't see bigger problems.

But you have to take care about ESD events at output. So, I would suggest to use some fast Schottky diodes from output pin to Vin and GND. Something like BAT54S, or so.
Excessive capacitive load at output can be troublesome with this sort of voltage references, because output looks like output of classical OPamp. If you want to use big capacitance for providing enhanced protection against ESD events, then you could use scheme published as 'Two Terminal -10Volt Reference' in datasheet. But this would allow only very small output currents in the range of a 1...2mA. Of course, '-10V Vref' gives your 'GND' and 'Analog GND' gives your '+10V'. Because battery application is totally floating this makes no problem at all.

An example:
Using 1.5kOhm resistor would cause a quiescent current through AD581 of (18V-10V) / 1.5kOhm = 5.3mA at 18V battery voltage (no external load). Then external load can draw up to 4.3mA.
If battery voltage falls down to 13V, quiescent current through AD581 is (13V-10V) / 1.5kOhm = 2.0mA (no external load). Then external load may only draw 1.0mA.
External load currents must not be greater than these values, because quiescent current through AD581 would then fall below minimum quiescent current and regulator would go out of regulation. Net current flowing through AD581 should always be between 1mA and 5mA.

Also, an undervoltage detector for battery voltage could be useful. Undervoltage takes place, when battery voltage falls below 13V.

Good luck,
Kai