Research on PVDF/BNNSs/MXene multilayer films with high energy density and thermal conductivity for dielectric capacitors

Polyvinylidene fluoride (PVDF) has promising applications in the field of dielectric capacitors. However, its low dielectric constant and thermal conductivity limit energy storage density. To address this, three multilayer composite topologies were designed with PVDF/boron nitride nanosheets as insulation and PVDF/MXene as polarization layers. A performance evaluation framework based on the analytic hierarchy process technique for order preference by similarity to the ideal solution method identified the insulation–polarization–polarization–insulation topology as the optimal configuration. This structure enhanced the dielectric performance (εr/tan δ) by 239.44% over pure PVDF at 103 Hz, increased thermal conductivity by 60.45%, and improved breakdown field strength. In addition, charge–discharge efficiency at 300 MV/m reached 75%, with a discharge density of 6.3 J/cm3, which is 152% higher than PVDF. The multilayer design effectively integrates the strengths of each layer to significantly enhance the overall performance, demonstrating that operational research methods are practical for evaluating dielectric materials and guiding design.