Novel Method Based on Spin-Coating for the Preparation of 2D and 3D Si-Based Anodes for Lithium Ion Batteries

Marie Gabard,Fouad Ghamouss,Virginie Grimal,Nathalie Poirot,David Chouteau,Thomas Tillocher,Mustapha Zaghrioui

doi:10.3390/chemengineering1010005

Abstract

The present study describes a novel strategy for preparing thin Silicon 2D and 3D electrodes for lithium ion batteries by a spin coating method. A homogeneous and stable suspension of Si nanoparticles (SiNPs) was prepared by dispersing the nanoparticles in 1-methyl-2-pyrrolidone (NMP) or in the room temperature ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (Pyr14TFSI). This proposed methodology was successfully employed to prepare 2D and 3D with different aspect ratios electrodes. Both 2D and 3D materials were then used as anode materials. The 2D SiNPs anodes exhibit a high reversible capacity, which is close to 3500 mAh·g−1 at C/10. For a higher discharge rate, the capacity of the 2D anode is considerably improved by dispersing the nanoparticles in Pyr14TFSI instead of NMP solvent. In order to further improve the anode performances, graphene particles were added to the SiNPs suspension. The anodes prepared using this suspension method exhibit relatively low columbic efficiency during the first few cycles (less than 30%) and low reversible capacity (2800 mAh·g−1 at C/10). The 3D SiNPs (NMP) electrode shows a higher intensity during cyclic voltammograms and a better stability under galvanostatic cycling than the 2D SiNPs (NMP) electrode.

Highlights

With the increasing need of miroenergy storage devices thanks to the miniaturization of biomedical implants, sensors, or integrated circuits, small size integrated batteries are required
Si anodes based on Si nanoparticles and their composites with carbonaceous materials have already been prepared using more traditional approaches, such as aerosol methods [14,15], freeze-drying [16], sonication followed by vacuum-filtration [17], mechanical blending [18], or low pressure chemical vapor deposition (LPCVD) [15]
The use of Pyr14TFSI allows amorphous carbon formation into the Si nanoparticles (SiNPs) layer, which could be related by its non-volatility and its tendency to decompose rather than evaporate, contrary to conventional solvents such as nanoparticles in 1-methyl-2-pyrrolidone (NMP)

Summary

Introduction

With the increasing need of miroenergy storage devices thanks to the miniaturization of biomedical implants, sensors, or integrated circuits, small size integrated batteries are required. Silicon is considered a promising material to prepare negative electrodes for Li-ion batteries due to its capacity of 3579 mAh·g−1 based on the alloyed form of Li15Si4 at room temperature [1,2]. Several nano- or micro-structured forms of silicon anodes have been reported and intensively explored to solve the silicon volume expansion/contraction problem during lithium insertion/extraction [3,4,5] These 3D materials show improved performances and durability due to their particular architectures that enable fast Li ion transport and facile strain relaxation. One can see that the nanostructured Si can provide sufficient intermediate space to withstand large volume expansion during the lithiation reaction Based on this viewpoint, we are focusing on Si anodes prepared by the deposition of Si nanoparticles (SiNPs) on a 2D and 3D silicon substrate using a spin coating technique. Si anodes based on Si nanoparticles and their composites with carbonaceous materials (e.g., graphene) have already been prepared using more traditional approaches, such as aerosol methods [14,15], freeze-drying [16], sonication followed by vacuum-filtration [17], mechanical blending [18], or low pressure chemical vapor deposition (LPCVD) [15]

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