The iPad 2 already has phenomenal, 10-hour battery life, largely thanks to a combination of Apple’s custom-built, power-sipping A5 chip and the fact that inside, the iPad 2 is mostly battery.

Thanks to a new, cutting-edge tablet coating, though, your next iPad could run for twenty hours or more on a single charge, while providing Kindle-like outdoor readability.

3M has just perfected a new optical film perfect for tablet displays that can greatly increase display brightness without increasing power drain.

Called a Brightness Enhancement Film, 3M’s new coating combines a 26 micron thin, high brightness reflective polarizer with a high efficiency back reflector. The result is incredible: tablet displays that look brighter, even though they are drawing half as much power and emitting half as much light.

Even better? 3M’s new tablet coating has no practical effect on display quality. In fact, it improves it markedly, especially in outdoor daytime environments… an environment where the iPad traditionally lacks compared to e-paper displays like that used in the Amazon Kindle.

And think the iPad 2 is already insanely thin? It could get even thinner, thanks to 3M’s new coating. In fact, 3M’s solution is 30% thinner than most existing backlight films.

If Apple leverages 3M’s technology in the next iPad, the end result could be a tablet that obviates all of the Kindle’s strengths short of a budget price: fantastic outdoor readability, wafer-thinness, and true all-day-battery life, all while boasting raw, next-gen performance and power.

As of writing, Apple has not yet responded for comment.

If you’d like to see 3M’s new tablet coating in person, it’ll be on display this week at SID Display Week 2011 in Los Angeles from May 16th through 20th.