Electrochemical Study on the Impact of Metallization on Si Particles for Li-Ion Negative Electrode

Li-ion batteries are widely used in a large number of devices that are used in everyday life, from Smart Devices to Hybrd Electric Vehicles (HEVs). The research is prompted towards the development of innovative materials that can further enhance the performances of batteries^1,2.

Research on anodic materials is of crucial importance to meet the requirements for cited applications in terms of power and energy density. On this side, Silicon is considered to be the most promising material in terms of deliverable theoretical specific capacity, 4200 mAh/g.  However, cycling performances of Silicon are jeopardized by the structural instability suffered from the material upon charge/discharge cycling. To address this issue, different solutions have been tested^3,4. The approach developed in this work is to apply a metallic coating to the Si particles by electrochemical techniques, i.e. electroless deposition and galvanic displacement.

In this work, a study of the electrochemical impact of the coating on the behavior of the electrode will be done in two steps. First, an assessment of the growth mechanism of metallic coating on Si particles will be carried out by means of SEM analysis. Then, the electrochemical characterization of electrodes containing metallized particles will be carried out by means of electrochemical impedance spectroscopy, SEM analysis and coin cell cycling.

References:

1. J. B. Goodenough and Y. Kim, Chem. Mater., 22, 587–603 (2010)

 2. Y. Sun et al., Nat. Mater., 11, 942–947 (2012)

 3. C. K. Chan et al., Nat. Nanotechnol., 3, 31–5 (2008)

 4. B. A. Boukamp, J. Electrochem. Soc., 128, 725 (1981)