Fig. 4: high resolution XPS spectra.

The high-resolution deconvoluted XPS spectra of a Cu 2p for Cu, b Fe 2p for SS, c Ni 2p for Ni, and d Al 2p for Al current collectors.
The high-resolution deconvoluted XPS spectra of a Cu 2p for Cu, b Fe 2p for SS, c Ni 2p for Ni, and d Al 2p for Al current collectors.