The icon for the Electric Boiler research is incredibly low-resolution. It looks like it's using the item sprite, which is intentionally tiny. You may want to use a version of the texture for the entity, as that's much higher-res.

i recreated one in good quality, will upload it soon

here we go : https://filetransfer.io/data-package/wTnWtwLZ#link

you can take it if you want mobius

I saw the update, I'll integrate the locale translation to french that you provided but I'll try to change the image, to have the blue glow

here we go : https://filetransfer.io/data-package/wTnWtwLZ#link

you can take it if you want mobius

link dead