Polyvinylidene fluoride (PVDF) - Trimethyl Aluminum (TMA) Chemistry: First-principles Investigation and Experimental Insights

The preparation of cathode electrodes has adhered to conventional methods, with limited exploration of the potential contributions of a remarkably robust yet relatively obscure reagent, trimethylaluminum (TMA), during atomic layer deposition (ALD). While significant research has focused on the interaction between TMA and cathode material particles, sparse attention has been devoted to investigating the interactions between TMA and polyvinylidene fluoride (PVDF), the predominant binder employed during cathode electrode preparation. This study presents a computational and experimental analysis of the degradation reaction observed between TMA and polyvinylidene fluoride (PVDF) using X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) investigations. An exothermic reaction mechanism was identified for the interaction of TMA with PVDF, yielding CH₄, dimethyl aluminum fluoride, and non-saturated carbons at the reaction site in the PVDF backbone. Our computational findings align well with XPS results, offering a robust theoretical-experimental correlation. Additionally, a secondary, slightly endothermic reaction pathway suggests the formation of hydrogen fluoride (HF) facilitated by the dimeric form of TMA, where TMA serves as an accelerant. The newfound chemistry involving TMA and PVDF could have substantial implications for optimizing industrial processes and developing novel materials, especially in energy storage and cleaner production technologies.