Article says 47 Wh/kg. Thats around a third of LFP cells. But the power density is way higher. Meaning it can do enormous peak currents.
For grid energy storage, energy density is not the most important factor, but the power density is a great plus. It means these cells can rapidly charge or discharge in the grid, offering flexibility to buffer in any way that is required. And the cycle life is also way higher.
Png is the right choice as it is lossless. Jpg works well for photos but it's not designed for abstract depictions such as the lines, panes and texts in applications and web sites. Meaning artifacts become noticeable with smaller jpg file sizes.