Development and Application of a Poly(acrylic acid)-Grafted Styrene–Butadiene Rubber as a Binder System for Silicon-Graphite Anodes in Li-Ion Batteries

Abstract

Silicon anodes require polymer binder systems that are both mechanically robust and electrochemically stable, to accommodate the dramatic volume expansion experienced during cycling operation. Herein, we report the use of a poly(acrylic acid)-grafted styrene−butadiene rubber (PAA-g-SBR) with 80% partially neutralized Na-PAA as the binder system for silicongraphite anodes. The PAA-g-SBR graft copolymer was synthesized by grafting tert-butyl acrylate onto SBR and treating the intermediate with H 3 PO 4 . The PAA-g-SBR/Na-PAA binder system was found to provide superior electrochemical performances to that of a Na-PAA/SBR system. The Na-PAA/PAA-g-SBR system had a stable capacity retention of 673 mAh g −1 for 130 cycles, while the capacity retention of the Na-PAA/SBR system was found to decline immediately. The Na-PAA/PAA-g-SBR system also displayed more preferable mechanical properties, with a lower Young's modulus value and a larger strain at failure compared to that of the Na-PAA/SBR system. Overall, these findings indicate a promising and robust polymer binder system for the application of silicon anodes in the next generation of lithium-ion batteries.

Role of Ether‐Based Electrolytes in Enhancing Potential of Potassium‐ion Batteries

“…This tendency is commonly observed for conversion electrodes that adopt a PAA binder. [ 157–159 ] Combining these findings with the work of Tan et al., [ 156 ] ether‐based electrolytes appear to result in the build‐up of thin and dense SEI layers, as PVDF binder is commonly used for potassium anodes as well. Therefore, the conversion anode undergoes substantial volume changes and is highly influenced by the binder and electrolyte.…”

Optimization of Si-containing and SiO based Anodes with Single-Walled Carbon Nanotubes for High Energy Density Applications

“…24 The combination of styrene butadiene rubber latex (SBR) to CMC will provide strong adhesion and introduce an element of flexibility to accommodate the volume expansion of silicon. 25 This test was only completed with 0.2 wt% SWCNTs as to not overshadow the electrochemical performance of the specific binder. Figure 4 shows a head-to-head comparison of SiO and SiO/Gr composite electrodes made using three different binders.…”

Limitations of Polyacrylic Acid Binders When Employed in Thick LNMO Li-ion Battery Electrodes

“…Additionally, the inclusion of other binders such as SBR can help compensate for the brittleness of polyacrylates and improve the overall properties of the binder. 47 In the future, extended efforts will be required to gain a more complete understanding, together with post-cycling characterizations, to further comprehend its microstructural and mechanical property changes with cycling and how they affect the electrochemical performance, providing effective guidance for practical applications. These should preferably incorporate tests also at higher mass loadings.…”