异质三明治结构柔性薄膜压电纳米发电机研究

Investigation on Flexible Thin Film Piezoelectric Nanogenerator with Heterogeneous Sandwich Structure

采用旋涂法制备不同质量分数还原氧化石墨烯(rGO)的PVDF/rGO复合薄膜。采用层层堆叠法构建层层组装异质三明治结构(PVDF/rGO-PVDF-PVDF/rGO)的压电纳米发电机(PNG)。系统研究了rGO掺杂、异质结构设计对压电输出性能的影响。研究结果表明,在掺杂rGO质量分数为0.4%时,单层PVDF/rGO复合薄膜压电纳米发电机的开路电压达到1.76 V,短路电流达到0.18μA。层层组装异质类三明治结构PVDF/rGO_(0.4)-PVDF-PVDF/rGO_(0.4)的PNG,开路电压高达7.72 V,是单层PVDF/rGO复合PNG的4.39倍;短路电流可达0.69μA,是单层PVDF/rGO复合PNG的3.83倍,这促进了电荷的转移,提高了电荷利用率。PVDF/rGO_(0.4)-PVDF-PVDF/rGO_(0.4)复合层层异质结构PNG经过4000次循环敲击测试,三层异质复合PNG压电输出稳定,有望在柔性可穿戴电子器件、人机交互及电子皮肤等领域得到广泛应用。

In this paper,the PVDF/rGO composite films with different mass ratios of reduced graphene oxide(rGO)were prepared by spin-coating method.The layer-by-layer assembly sandwich heterostructure PVDF/rGO(PVDF/rGO-PVDF-PVDF/rGO)piezoelectric nanogenerator(PNG)was manufactured via the layer-by-layer stacking method.The effects of the rGO doping and heterostructre design on the output performance of PNG have been systematically studied.The results showed that the open circuit voltage and short circuit current of the single layer PVDF/rGO composite films PNG were up to 1.76 V and 0.18μA respectively when the rGO doped mass fraction was 0.4wt%.The open circuit voltage of the PNG with layer-by-layer assembly sandwich-like heterostructure PVDF/rGO_(0.4)-PVDF-PVDF/rGO_(0.4) was as high as 7.72 V,which was 4.39 times that of the single-layer PVDF/rGO composite PNG,and the short circuit current was as high as 0.69μA,which was 3.83 times that of single-layer PVDF/rGO composite PNG,which promotes the transfer of electric charge and improves the utilization rate of electric charge.Over 4000 pressing-releasing cycles tests of the PNG with PVDF/rGO_(0.4)-PVDF-PVDF/rGO_(0.4) composite layer-by-layer heterostructre have been carried out.The results show that the three-layer heterogeneous structure composite PNG has stable piezoelectric output,which is expected to be widely used in the fields of flexible wearable electronic devices,human-computer interaction and electronic skin.