Apple is working with South Korean companies LG and Samsung for the new Apple Watch have this thinner OLED displays (OLED) and allow the device a battery room for more capacity.
As we named in the title, this is just rumors circulating among South Korean suppliers of LG and Samsung.
According to the report of Naver, Apple Watch 2 will have the same screen size and resolution than the current generation. However, the screen will be slightly thinner, allowing a slightly larger than currently brings battery. Therefore, this should lead to an improvement in battery life for Apple Watch 2.
Apple could also use the new hexagonal LG batteries in Apple Watch 2 as they are 25% more efficient than traditional rectangular batteries.