Li Jie, Li Liang-Yu, Jia Peng, Okulov Ilya V
Materials Mechanics, Institute of Materials Research, Helmholtz-Zentrum Hereon, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Nanomaterials (Basel). 2022 Jun 22;12(13):2149. doi: 10.3390/nano12132149.
Due to the high demand of wearable electronics, flexible supercapacitors have been extensively developed in recent years. Yet, the effect of deformation in the interior electrode material suffered in practical applications on the performance received less attention. Here, we study the electrochemical behavior of macroscopic nanoporous gold/polypyrrole (NPG/PPy) in situ under compression deformation. Dealloying-driven NPG, a network constructed by bi-continuous nano-scaled ligaments and pores, can serve as a compression-tolerant substrate for PPy supercapacitor material. The electrochemical capacitance of NPG/PPy subjected to compression deformation is revealed to decrease at the scan rates and discharge current densities applied in this work. At the same time, the charge transfer resistance of NPG/PPy is found to increase. This electrochemical behavior is due to the locally reduced mass transport of electrolyte caused by the formation of new connections between the neighboring ligaments under the application of compression loads. The fundamental understanding of the effect of deformation on the performance of energy storage materials revealed in this study paves the way for their practical application in wearable devices.
由于可穿戴电子产品的高需求，柔性超级电容器近年来得到了广泛发展。然而，实际应用中内部电极材料所受变形对其性能的影响却较少受到关注。在此，我们研究了宏观纳米多孔金/聚吡咯（NPG/PPy）在压缩变形下的原位电化学行为。通过脱合金化制备的NPG是一种由双连续纳米级韧带和孔隙构成的网络结构，可作为PPy超级电容器材料的耐压基底。研究发现，在本工作所采用的扫描速率和放电电流密度下，经受压缩变形的NPG/PPy的电化学电容会降低。同时，NPG/PPy的电荷转移电阻增大。这种电化学行为是由于在压缩载荷作用下相邻韧带之间形成新连接，导致电解质的局部传质减少。本研究中对变形对储能材料性能影响的基本认识为其在可穿戴设备中的实际应用铺平了道路。
