Trapping Ions to\nEnhance High-Field Energy Harvesting\nPerformance by Filling Polar Macromolecular Dielectrics

In the quest for sustainable and renewable energy sources,\nresearchers\nand engineers have explored innovative technologies to harvest energy\nfrom various environmental sources. Dielectric elastomer generators\n(DEGs) with high energy harvesting performance have been proven to\nbe promising energy collectors, but achieving a high dielectric constant\n(ε’) and low electrical conductivity (<i>EC</i>) under high electric fields of dielectric elastomer (DE) simultaneously\nis a struggle, which poses significant challenges. In this study,\nhigh-content carboxyl group-grafted liquid polybutadiene (HCPB) is\nsynthesized and then adopted as an organic dielectric filler to blend\nand cocross-link with a butadiene rubber (BR) matrix to prepare DE\ncomposites with high energy harvesting performance. The introduction\nof carboxyl groups enhances polarization while trapping free Al<sup>3+</sup> in the matrix, which revolutionarily achieves a significant\nincrease in ε’ under extremely low <i>EC</i>. Ultimately, the contradiction between increased ε’\nand decreased <i>EC</i> under high electric fields is reconciled,\nresulting in a 30 HCPB/BR composite with high energy density (<i>w</i> = 91.9 mJ/cm<sup>3</sup>) and fine power conversion efficiency\n(<i>PCE</i> = 24.1%). This advancement paves the way for\nthe development of HCPB/BR composite-based DEGs with enhanced ε’\nand energy harvesting performance.