Effect of binder modification on the performance of thick electrodes with microstructures fabricated by femtosecond laser

Lithium iron phosphate (LFP) thick electrodes have emerged as a key strategy to enhance the energy density of lithium-ion batteries. However, their practical performance is limited by sluggish ion/electron transport. While femtosecond laser-induced porous micro/nanostructures effectively mitigate transport limitations, this structuring approach often reduces mechanical cohesion and risks electrode delamination. The conventional polyvinylidene fluoride (PVDF) binder, with weak adhesion and insulating properties, worsens these issues. This study developed a multifunctional composite binder (PPC) of PVDF, polyacrylonitrile (PAN), and carboxylated multi-walled carbon nanotubes via ultrasonic dispersion. The PPC binder improves interfacial adhesion through polar nitrile interactions and establishes a conductive network, enhancing mechanical robustness and electronic conductivity. The synergistic integration of laser-structured structure and the composite binder significantly enhances electrode adhesion, rate capability, and long-term cycling stability, offering a solution to the performance–durability trade-off in thick electrodes.