Exploring Conductive Materials for Lithium Iron Phosphate(LFP) Dry Electrodes
Authors: Kim Byeongjin , Kim DaeKyom , Yoo Youngjae 
Published: December 2024

In light of the emerging focus on sustainable and efficient battery production technologies, the necessity for dry electrode manufacturing has become increasingly apparent. This necessity arises particularly due to the environmental and health hazards associated with the use of N-Methyl-2-pyrrolidone (NMP) in conventional electrode manufacturing processes. NMP's toxicity poses significant risks upon inhalation or skin contact, while its evaporation and recovery processes contribute to environmental pollution and incur substantial costs. Moreover, the limitations inherent in the wet process, including constraints on slurry layering on the current collector, impede the achievement of higher energy densities and elevate manufacturing costs. Conversely, the solvent-free thick film dry electrode method presents a promising alternative, enabling reductions in battery stack thickness, which in turn facilitates higher energy densities and diminishes the demand for current collectors and separators, thus offering a more economical approach than traditional wet process electrodes.

The selection of Lithium Iron Phosphate (LFP) as the active material is predicated on its exceptional safety profile, long cycle life, and thermal stability—attributes that are paramount for applications demanding high reliability and safety, such as electric vehicles and stationary energy storage systems. However, the adaptation of LFP into dry electrode configurations demands a thorough investigation into conductive additives to optimize performance. It is in this context that our study aims to explore the under-researched area of conductive additives for LFP dry electrodes, focusing on Multi-Walled Carbon Nanotubes (MWCNT), Super P carbon black, and Graphite Nanoplatelets (GNP). The choice to investigate these specific additives stems from their promising electrical conductivity and potential to improve mechanical integrity within the electrode structure.

Employing a suite of advanced morphological and mechanical analytical techniques, our research endeavors to scrutinize the impact of these conductive additives on the performance of LFP dry electrodes. Morphological analyses, conducted through Scanning Electron Microscopy (SEM) and potentially Transmission Electron Microscopy (TEM), aim to illuminate the microstructural effects of the conductive additives on the LFP matrix. These analyses are vital for discerning the mechanisms of electron transport and achieving a uniform distribution of active materials, directly influencing the electrode's electrochemical performance.

Moreover, the study extends to evaluating the mechanical properties of the electrodes, utilizing Universal Testing Machine (UTM) measurements and rheological analysis to ascertain their tensile strength, flexibility, and viscoelastic properties. These mechanical assessments are instrumental in understanding the electrodes' resilience under operational stresses, thereby ensuring their durability and structural integrity.

By venturing into this exploratory study, we anticipate unveiling insights that could significantly contribute to the development of more efficient, reliable, and safer LFP batteries. This endeavor not only aims to broaden the current understanding of the role of conductive additives in dry electrodes but also to facilitate the advancement of battery technologies that are environmentally benign and economically viable, aligning with the global shift towards sustainable energy solutions.