Lithium polyacrylate polymer coating enhances the performance of graphite/silicon/carbon composite anodes

In this study a graphite (Gr)/silicon (Si)/carbon (C) (Gr +C:Si = 85:15, wt.%) composite anode material was prepared through spray-drying and then subjected to wet-coating in an aqueous solution to obtain lithium polyacrylate (LiPAA)-coated Gr/Si/C composite anode materials. The thickness of the LiPAA coating layer of the 1 wt.% LiPAA-coated Gr/Si/C anode material was approximately 4 nm. The characteristics of the LiPAA-coated Gr/Si/C composite materials were examined using X-ray diffraction, micro-Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, the Brunauer- Emmett-Teller method, scanning electron microscopy/energy dispersive X-ray spectroscopy, and transmission electron microscopy. The capacity retentions of CR2032 half-cells featuring the pristine Gr/Si/C composite electrode were ca . 74.0% at 0.2C after 100 cycles and 30.0% at 0.5C after 500 cycles; they improved markedly-up to 94.4% and 82.2%, respectively-for the cells prepared with the 1 wt.% LiPAAcoated Gr/Si/C composite electrode. The LiPAA polymer coating functioned as an artificial solid electrolyte interphase layer that stabilized the structural integrity at the interface between the electrode and the electrolyte during the cycling process. Our experimental results suggest that LiPAA-coated Gr/Si/C composites are promising candidate materials for use as high-capacity anodes in next-generation lithium-ion batteries. (c) 2020 Elsevier Ltd. All rights reserved.

Automated summary

In this study, LiPAA-coated Gr/Si/C composite materials were prepared and showed improved capacity retentions during cycling tests. The LiPAA polymer coating stabilized the interface structure between the electrode and the electrolyte during the cycling process.