Effect of ex situ hydrogenation on the structure and electrochemical properties of amorphous silicon thin film

• Published in: Journal of solid state electrochemistry 2021-10, Vol.25 (10-11), p.2539-2548
• Main Authors: Zhang, Hai-min, Luo, Yong-chun, Yang, Song-ting, Xiang, Yu-jie
• Format: Article
• Language: English
• Subjects: Amorphous silicon; Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Discharge; Electrochemical analysis; Electrochemistry; Electrodes; Energy Storage; Hydrogen storage; Hydrogen storage materials; Hydrogenation; Metal hydrides; Nickel; Original Paper; Photovoltaic cells; Physical Chemistry; Rechargeable batteries; Silicon films; Thin films
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-021-05038-1

Nickel-metal hydride (Ni-MH) batteries were widely used due to their various advantages, but its further application and development have been seriously hindered by the low electrochemical discharge capacity of conventional hydrogen storage alloy electrode. The hydrogenated amorphous silicon (a-Si:H) thin film electrode for Ni-MH battery has been proven to have a dramatic electrochemical capacity. We prepared a-Si:H thin films by a two-step process of rf-sputtering followed by hydrogenation, and investigated the effect of hydrogenation on the structure and electrochemical properties of which as an anode. The maximum discharge capacity of a-Si:H thin film electrode after hydrogenation increases from initial 180 mAh·g −1 to 1827 mAh·g −1 , which is over tenfold that of as-deposited hydrogen-less a-Si thin film electrode. Then, the preliminary relationships between hydrogen content and electrochemical performance of a-Si:H thin film electrode were analyzed, and several negative factors of electrochemical performance for a-Si:H thin film electrode were proposed.