Electrochemical properties of polydopamine coated Ti-Si alloy anodes for Li-ion batteries

Autor: Ji-Sun Lee, Sung-Man Lee, Min-Seon Shin
Rok vydání: 2016
Předmět:
Zdroj: Electrochimica Acta. 222:1200-1209
ISSN: 0013-4686
DOI: 10.1016/j.electacta.2016.11.094
Popis: We report a strategy to enhance the cycling performance of a Ti-Si alloy anode by coating it with Polydopamine (PDA) as an adhesive and elastic polymer layer. The PDA was coated on a Ti-Si alloy prepared using the mechanical alloying method. The PDA coating is confirmed by X-ray photoelectron spectroscopy (XPS) and cross sectional transmission electron microscopy (TEM). The PDA coated Ti-Si alloy shows improved cycling performance with enhanced coulombic efficiency during cycling. Because the PDA coating suppresses direct contact between the Ti-Si alloy and the electrolyte during charge-discharge cycling and, hence, the initially formed SEI film remains in a stable state during cycling. After 50 cycles, the SEI layer formed on the alloy particles is much thicker in the bare alloy electrode than in the PDA coated alloy electrode. This result is supported by electrochemical impedance spectroscopy (EIS) measurement and cross-sectional scanning electron microscopy (SEM) images before cycling and after 50 cycles.
Databáze: OpenAIRE