3. Results and discussion
Scheme 1 shows the fabrication process of ErCl3 electrode. ErCl3
electrodes were prepared by pasting a slurry mixture of commercial
ErCl36H2O salts, carbon black, and poly(vinylidene fluoride)
(PVDF) on a Ni foam, which did not need the additional complex
synthesis procedures for active materials. The present results challenge
the view that the synthesis of advanced materials is the key