Silver Nanowires Epsilon-Negative Metacomposites in Constructing Laminated Structure Meta-Capacitors.

Epsilon-negative metacomposites with remarkable super-coupling, tunneling, and local field enhancements characteristics have attracted extensive attention. Under the growing demand for superior energy storage and conversion efficiency of capacitors, conventional materials can not fulfill the requirements in balancing the trade-offs of dielectric constant, losses, and energy density. New insights into the design and functionality of laminated structure meta-capacitors are presented, which can provide an effective solution to these limitations. The proposed meta-capacitors are made of polyvinylidene fluoride (PVDF), barium titanate (BaTiO₃), and silver nanowires (AgNWs), which exhibit excellent dielectric properties and higher stored/discharged energy density. Specifically, epsilon-negative behavior is derived from plasma oscillation via constructing percolation networks. Consequently, the dielectric constant of meta-capacitors is significantly enhanced to 59.74, which is more than six times that of pristine PVDF of 9.95, while the loss tangent is lower than 0.035. Notably, compared with conventional devices, the meta-capacitors have shown higher energy storage and discharge density, which is increased by 148% and 133% respectively. This work highlights the potential of laminated structure meta-capacitors in promising energy applications, which can provide valuable insights for next-generation energy storage devices.