Although the technology involved in actually taking a picture is evolving exponentially, this is not necessarily the case when it comes to digital camera batteries. There are advances in battery tech, for instance Lithium ion batteries are roughly twice as long lived as Alkaline batteries, however even the most advanced camera batteries are far from immortal.
Some digital cameras use normal AA batteries. These kinds of cameras are becoming less popular, and the norm is to have a dedicated camera battery pack which you can recharge. A possible advantage with using AA batteries is that they can be very easily replaced and you can carry lots of spares around with you.
However, overall a dedicated battery pack will probably be better. They are rechargeable and there is nothing stopping you from purchasing a spare battery pack if you’re ever worried about it running out of juice if you’re out and about.
If you want to get the most out of your camera battery’s lifespan then the way you use the camera matters. Modern cameras obviously have lots of functionality, LCD screens, video taking capabilities etc. Each one of these functions consumes power and so they should be switched off when not in use.
If you have a camera for a very long time then you might notice that the battery loses some of its performance. There is no way to improve a batteries performance although you can replace a battery by looking online for a compatible product.