With batocera, 7z can’t usually decompress. (It seems possible if you modify it, but I don’t know and it’s not supported.) Just put the prepared rom file compatible with batocera in the rom folder.
Is there “_info.txt” in the psx folder inside the roms folder?
excerpt
## SYSTEM SONY PLAYSTATION 1 ##
---———————————————– —————————–
ROM files extensions accepted: “.cue .img .mdf .pbp .toc .cbn .m3u .ccd .chd .iso”
For more info: https://wiki.batocera.org/systems:psx
---———————————————– —————————–
Extensions des fichiers ROMs permises: “.cue .img .mdf .pbp .toc .cbn .m3u .ccd .chd .iso”
Trouvez la documentation ici: https://wiki.batocera.org/systems:psx