Significantly enhanced energy storage performance of PMMA polymer by filling an ultralow content of ultrathin 2D BiOCl nanosheets

Polymer nanocomposites with high energy density hold great promise for the future miniaturization of dielectric capacitors in modern electronics. However, their performance is limited by the poor dispersion of inorganic fillers and severe interfacial electric field distortion. To address the above challenges, ultrathin two-dimensional (2D) BiOCl nanosheets are employed as the nanofiller for the first time, achieving excellent energy storage performance for the PMMA-based nanocomposites. Remarkably, the nanocomposite film with 0.5 wt% 2D BiOCl exhibits an outstanding energy storage density of 13.28 J/cm 3 and charge-discharge efficiency of 86.11 %, which is 108 % and 13.4 % higher than that of the pristine PMMA . Furthermore, the underlying enhancement mechanism is elucidated by finite element simulations. This work highlights the exceptional potential of 2D BiOCl as a novel nanofiller for designing high-performance polymer nanocomposites.