Recently, a research team led by Professor Wang Zhenyang from the Institute of Solid State Physics (HFIPS) of the Hefei Institute of Physics reported a new method for preparing high-performance supercapacitors with ultra-high energy storage density.
Constructing a 3-D graphene framework with ultra-thickness and rich ion migration paths is of great significance to the practical application of graphene supercapacitors. However, in thicker electrodes, the total energy storage capacity is limited by insufficient ion delivery to the electrode material surface and poor electron transport performance.
In this work, by optimizing the thermal sensitivity of polyimide to increase the laser penetration depth, it is possible to directly grow a laser-induced ultra-thick 3-D graphene skeleton with a thickness of 320 μm on the synthesized polyimide. Therefore, layered pores are obtained due to the rapid release of gaseous products during laser irradiation, which promotes rapid ion transmission.
This new structure balances the contradiction between electrode thickness and fast ion transport. The pseudo-capacitive polypyrrole was further introduced into the graphene framework to prepare a composite electrode, the specific capacitance of which was as high as 2412.2 mF cm-2 At 0.5 mA cm-2.
Therefore, a flexible solid-state miniature supercapacitor with a high energy density of 134.4μWhcm is constructed-2 At a power density of 325μWcm-2.
These results indicate that these ultra-thick graphene electrodes have great potential in the application of supercapacitors with high energy storage density.
New electrode configuration improves the volume performance of supercapacitors
Yu Xinling et al. Super-thick 3D graphene frame with layered holes for high-performance flexible miniature supercapacitors, Power Magazine (2020). DOI: 10.1016 / j.jpowsour.2020.229075
Provided by Chinese Academy of Sciences
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