The SEM image, nitrogen adsorption–desorption isotherm and pore size distribution (PSD) of the electrode are shown in Fig. SM-2.
The SEM image displays that the addition of the PTFE polymer to AC powder yields excellent physical stability.
Note that the isotherm exhibits obvious hysteresis at high relative pressure, suggesting the presence of mesopores.
The BET specific surface area is 300 m2 g1, while the micropore surface area is 98 m2 g1.
The PSD curve displays that most of the pores are above 1 nm, which is beneficial to ion adsorption.