Since they use liquid electrolytes, which leads to dendrites formation on the cathode and anode of the batteries, which can end up shorting the battery. The point of solid state batteries (if they ever can be made at scale) is to prevent that with (hopefully) better energy density and charge time than our current battery tech
basically, Retailleau is in the government thanks to a pseudo coalition between his party and other parties (mostly right wing). He is also challenging the leadership of his party from the current leader, Laurent Wauquiez, with the 2027 election ballot in the balance. So atm he's trying his best to rile up the rightmost voters as much as he can with every speechs and official acts.
that being said, the rest of the government is also a shitshow rn
Since they use liquid electrolytes, which leads to dendrites formation on the cathode and anode of the batteries, which can end up shorting the battery. The point of solid state batteries (if they ever can be made at scale) is to prevent that with (hopefully) better energy density and charge time than our current battery tech