[15p-D209-1~12] 7.2 Applications and technologies of electron beams

▲ [15p-D209-4] In situ scanning electron microscopy observation of ion distribution variation
at the electrode-electrolyte interface in an electrochemical cell

〇Gada He¹, Yoshifumi Oshima¹, Masahiko Tomitori¹ (1.JAIST)

Keywords:scanning electron microscopy, electrochemical cell, electroplating and stripping

We developed a conventional in-situ electrochemical cell with two electrode terminals for SEM to observe the processes of electro-plating and stripping simultaneously with measuring the cyclic voltammetry. The cell was sized to fit into the small space of the custom-made specimen holder for Hitachi S-5200 Fe-SEM with several current feedthroughs, each of which was connected to a coaxial cable. When the applied potential was varied from the outside of the SEM, electrochemical reactions occurred at the end of the vapor-deposited electrode and were observed through a small thin silicon nitrite membrane window of TEM grid with a thickness of 50 nm, through which the SEM electron beam was able to pass. We observed in-situ consecutive SEM images of electro-deposition and stripping of Pb on the Au electrode through the SiN membrane window while measuring the cyclic voltammogram. The SEM images clearly showed that the electro-deposition and stripping of Pb on a nanoscale, which were consistent with the cyclic voltammogram curves. From the SEM observation, we distinguish the growth modes of Pd deposits, exhibiting the particulate band structures and dendrite strucutres, depending on the roughness of the electrode. The brightness of SEM images in the electrolyte region changed in the course of the cyclic voltammetry, which implied the change of Pb concentration of the electrolyte near the electrode. This study demonstrated the potential of in-situ high-resolution SEM combined with the electrochemical cell.