| ZHONG Li,LIAO Shengzhao,KANG Jun,HAN Xi.Structure Optimization and Capacitive Properties of Porous Graphene Films[J],54(4):221-232 |
| Structure Optimization and Capacitive Properties of Porous Graphene Films |
| Received:April 02, 2024 Revised:May 16, 2024 |
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| DOI：10.16490/j.cnki.issn.1001-3660.2025.04.018 |
| KeyWord:porous graphene films structure optimization pre-carbonization process multi-step laser etching capacitive performance |
| Author | Institution |
| ZHONG Li |
School of Mechatronics and Vehicle Engineering,Chongqing , China |
| LIAO Shengzhao |
School of Mechatronics and Vehicle Engineering,Chongqing , China |
| KANG Jun |
Institute of Solid-State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei , China |
| HAN Xi |
School of Civil Engineering, Chongqing Jiaotong University, Chongqing , China |
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| Abstract: |
| With the increasing demand of energy, high energy storage and excellent conversion efficiency are urgently needed by energy storage devices. Therefore, the research of electrochemical energy storage devices with both high energy density and high-power density is still a challenge. To further improve the capacity of electrochemical energy storage devices, more precise material science analysis has been conducted on electrochemical energy storage, revealing that the performance of electrochemical energy storage devices is related to the structure of electrode materials. Nowadays, a plenty of studies have found that three-dimensional porous graphene with macro thickness is one of the ideal electrode materials for electrochemical energy storage devices. Due to the strict experimental conditions and preparation technology, the crystal quality and pore connectivity of porous graphene as electrode materials are still worthy of further improvement. Commercial phenolic resin (PR) is one of the ideal precursors for the preparation of porous carbon materials due to its high carbon residue rate. The phenolic resin is pretreated at high temperature to obtain a stable structure, and then the optimized pore structure and crystal quality are expected to be obtained on the phenolic resin derived graphene films by low energy laser etching, thus significantly improving the electrochemical properties. Besides, laser induced technology for the preparation of graphene materials has gradually become the mainstream way for the preparation of porous graphene due to its simple method, rapid synthesis, low cost, and low environmental pollution characteristics. However, the limited ions transport efficiency still remains. In this work, under the above condition, the graphene precursor was carbonized in advance, and then the structure of the porous graphene films was optimized by low-energy multi-step laser etching. The surface morphology, crystal quality, wettability and electrochemical properties of the prepared graphene films were characterized. The pre-carbonization of the graphene precursor for 2 h at 300 ℃ could improve the stability of the graphene film material prepared in the subsequent multi-step laser treatment. The pre-carbonization process caused the decomposition of small organic molecules in the precursor, and the internal cross-linking degree became higher, which could better cope with the repeated etching of CO2 laser. The results of Raman spectroscopy revealed that the graphene structure optimization process could be directly observed in the process of low energy laser repeated etching, which was of great significance for screening the optimal graphene film structure. SEM images demonstrated that the pre-carbonized carbon precursor derived graphene films at 300 ℃ had a typical three- dimensional network porous structure, which provided a reliable structure for efficient ion transport. During the electrochemical performance test, the area specific capacitance reached 124.6 mF/cm2 in 1 mol/L H2SO4 solution, and excellent storage capacity and cycle stability were maintained after assembly into a MSC device. In this paper, the ion transport problem is improved by optimizing the structure of porous graphene films, and the electrochemical performance is significantly improved, which is important for the design of graphene electrode with both high electrical storage capacity and excellent stability. |
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