Hello Subevo,
the main difference between lifepo4 and lifeypo4 is additional Yttrium at the cathode of the lifeypo4 cells to speed up electron transfer especially at cold temperatures. They are the better choice, especially for electric car usage. I received my cells in spring of last year, my car was one of the first conversions done with Yttrium cells. While driving through the whole last winter here in Germany I´m very surprised of these cells providing high amps at cold, freezing temperatures. I was able to drive my car at the coldest days. Without Yttrium this should not be possible regarding the experience of others. The voltage sag under freezing point is too much with the old cells. Yttriums sag a little bit, but you´re able to drive and receive the whole stored energy. Believe me, they´re really good.
Roger