[squarefoot]

"sodium chloride (Na/Cl2)"

I'm not chemist, but if I recall correctly, sodium chloride is NaCl, not NaCl2, ie common kitchen salt.

[rsfern]

The primary reaction at the cathode is reported as Na + 0.5 Cl2 <-> NaCl

(Reported in the paper, which is unfortunately not open access. https://www.nature.com/articles/s41586-021-03757-z)