Not exactly.
The thing is, iCloud Photo Library is specifically meant to be a library synced across your devices - they all have copies of the same images, whether they are full-resolution or optimized. That’s the purpose of the feature.
I haven’t tried this because I don’t yet use iCloud Photo Library, but in theory you might be able to work around this if you have a Mac:
1) Disable iCloud Photo Library on the phone
2) Enable Photo Stream on the phone
3) Enable both iCloud Photo Library and Photo Stream on your Mac
4) Make sure the Mac is set to download and store original, full-resolution versions of photos and videos
My theory here is that the phone will send new photos you take to your Photo Stream, the Mac will download them from the Photo Stream, and then add them to iCloud Photo Library. If you do try this, I’d love to hear if it actually works.
I should note that I suspect Apple will get rid of Photo Stream somewhere down the line. It’s an older feature, which iCloud Photo Library is no doubt intended to supercede in their mind. Yes, they work differently, but from Apple’s point of view they duplicate syncing functionality and Apple probably wants to simplify this in the future.