Renewable Lignin-Derived Graphene-like/PVDF Nanocomposites with High Dielectric Constant and Low Loss Tangent

Dielectric materials with high dielectric constant, low loss tangent, and lower cost need to be developed, given the growing demand for advanced electronic devices and energy systems. We present the first attempt to use a renewable lignin-derived graphene-like (LG) filler prepared by a simple, low-cost, and scalable approach to enhance the dielectric properties of polyvinylidene fluoride (PVDF)-based nanocomposite. LG/PVDF nanocomposites were fabricated via simple blending and solvent-casting methods. The LG/PVDF nanocomposites outperform previously published research utilizing conventional graphene filler, with a low percolation threshold fc = 0.09. At room temperature and 1 kHz, the nanocomposite with the volume fraction of LG filler fLG = 0.08 exhibits a high dielectric constant value of 107, which is ∼12 times higher than pure PVDF while retaining a low loss tangent of 0.06. The main mechanisms for the excellent dielectric properties were proposed to be related to the Maxwell–Wagner–Sillars (MWS) polarization of the LG filler and the formation of local microcapacitor structure. This work could pave the way for the next generation of environmentally friendly dielectrics with exceptional dielectric characteristics for high-performance energy storage devices by composing renewable graphene and polymer composite systems and opening critical roadblocks to superior dielectric performance of percolative materials.