Journal Article

Sputtering Deposition of Sn–Mo-Based Composite Anode for Thin-Film Li-Ion Batteries

Balaji, S., Mani Chandran, T.

2016

Overview

The role of electrochemically inactive molybdenum in alleviating the anomalous volume expansion of tin anode upon charge–discharge cycling has been investigated. Tin–molybdenum thin-film composite anodes for Li-ion batteries were prepared using a direct-current sputtering method from a tin metal target incorporating molybdenum element. Results of structural and compositional analyses confirmed the presence of tin and molybdenum. The elemental ratio obtained from energy-dispersive x-ray spectroscopy confirmed the feasibility of tailoring the thin-film composition by varying the ratio of metallic elements present in the sputtering target. Scanning electron micrographs of the samples revealed the occurrence of flower-like open morphology with Mo inclusion in a Sn matrix. The gravimetric discharge capacity for pure Sn, Sn-rich, and Mo-rich samples was 733 mAh g −1 , 572 mAh g −1 , and 439 mAh g −1 , respectively, with capacity retention after 50 cycles of 22%, 61%, and 74%, respectively. Mo inclusion reduced the surface resistivity of the Sn anode after the initial charge–discharge cycle. The charge-transfer resistance after the first cycle for pure Sn, Sn-rich, and Mo-rich samples was 17.395 Ω, 5.345 Ω, and 2.865 Ω, respectively. The lithium-ion diffusion coefficient also increased from 8.68 × 10 −8 cm 2 S −1 for the pure Sn sample to 2.98 × 10 −5 cm 2 S −1 for the Mo-rich sample.

• Publisher: Springer US,Springer Nature B.V
• Subject: Batteries / Characterization and Evaluation of Materials / Chemicals / Chemistry and Materials Science / Composite materials / Electronics / Electronics and Microelectronics / Instrumentation / Ions / Materials Science / Optical and Electronic Materials / Solid State Physics / Thin films