Multifunctional Liquefiable Oligomer Additive for Dry Electrode Process

The polytetrafluoroethylene (PTFE)-based dry electrode process (DEP), which enables electrode fabrication without using solvents, has gained considerable attention in the lithium-ion battery (LIB) industry due to its environmental friendliness and cost-efficiency. However, the inhomogeneous dispersion and reductive instability of PTFE in LIB anodes have hindered the commercial implementation of DEP. To overcome this challenge, herein, we introduce liquefiable oligomers as multifunctional additives for PTFE-containing graphite anodes fabricated via DEP. Specifically, we identify poly(propylene glycol) with a molecular weight of 2,000 (PPG 2k) as an optimal candidate that simultaneously functions as a lubricant and an electronic transport barrier. This multifunctional additive promotes PTFE’s fibrillation while mitigating its reductive degradation in anodes, leading to substantial improvements in both processability and electrochemical performance. Furthermore, PPG 2k facilitates the formation of desirable inorganic solid-electrolyte-interphase (SEI) components by modifying the lithium-ion solvation structure. This study highlights liquefiable oligomers as promising additives for DEP.