介电调控摩擦材料表面电荷密度及影响电荷迁移机制研究

摩擦电技术可将环境中机械能转化为电能，为电子器件稳定持续供能。然而，较低的输出功率是限制其作为独立电源广泛应用的瓶颈。摩擦材料表面电荷密度是影响器件电功率的关键，本项目拟结合摩擦电荷的产生、捕获/存储与泄漏三方面，通过调控介电性能及优化结构设计多功能夹层结构摩擦复合材料，显著提升材料表面电荷密度及器件电功率密度。拟采用策略是：（1）制备多孔铁电聚合物PVDF-TrFE摩擦层，结合铁电及压电效应，提高材料表面电荷生成；（2）制备高介电常数钛酸钡（BaTiO3）纳米复合材料，提升材料电荷捕获和存储能力；（3）复合材料改性优化，降低界面缺陷及介电损耗，构筑氮化硼（BN）电荷阻隔层，抑制泄漏电流，避免摩擦电荷与电极诱导电荷中和。通过控制各层结构参数来调控复合材料介电性能和表面电荷密度，阐明介电参数对摩擦电荷迁移的影响机制，建立“结构-介电-摩擦电”构效关系，促进新型摩擦材料及高功率密度器件的发展。

Triboelectric technology can convert various mechanical energy into electrical energy, which can provide stable and continuous electric power for smart electronic devices. However, its low output power is a bottleneck that limits its wide application as an independent power source. As the surface charge density is a key factor of triboelectric performance, this research intends to investigate the generation, trapping and leakage of triboelectric charges, and fabricate multifunctional composite friction layer via dielectric modulating and structure optimizing, for improving the surface charge density of triboelectric materials and the electrical power density of triboelectric devices. The proposed strategies are as follows: (1) Preparation of porous ferroelectric PVDF-TrFE friction layer for enhancing the triboelectric charge generation. (2) Fabrication of Barium Titanate (BaTiO3) based nanocomposites with high dielectric constant for strengthening the charge trapping and storing capacity of the triboelectric materials. (3) Modification of BaTiO3 and construction of boron nitride (BN) charge blocking layer for reducing interface defects and dielectric loss of composite materials, and inhibiting the leakage current of composite materials originated from the neutralization of friction charges with induced charge on the electrode. Through controlling the structural parameters of each functional layer, the dielectric properties and triboelectric properties of the nanocomposites can be adjusted. In addition, this research can establish the theoretical model of "structure-dielectric-triboelectric" and reveal the influence of dielectric parameters on the charge transfer mechanism, which will provide a new approach for constructing high-performance triboelectric materials and devices.