How to pronounce 石墨 in Cantonese (7 out of 9):

石墨烯雙芯電池
It's a double-core battery.

Cantonese Sentence Breakdown

石墨 sek6 mak6
graphite
jing1
alkene
soeng1
double
pair
seon3
the tongue of a snake
電池 din6 ci4
battery