Baboo Joseph Paul, Babar Shumaila, Kale Dhaval, Lekakou Constantina, Laudone Giuliano M
Centre for Engineering Materials, Department of Mechanical Engineering Sciences, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK.
Faculty of Science and Engineering, University of Plymouth, Plymouth PL4 8AA, UK.
Nanomaterials (Basel). 2021 Oct 29;11(11):2899. doi: 10.3390/nano11112899.
Graphene electrodes are investigated for electrochemical double layer capacitors (EDLCs) with lithium ion electrolyte, the focus being the effect of the pore size distribution (PSD) of electrode with respect to the solvated and desolvated electrolyte ions. Two graphene electrode coatings are examined: a low specific surface area (SSA) xGNP-750 coating and a high SSA coating based on a-MWGO (activated microwave expanded graphene oxide). The study comprises an experimental and a computer modeling part. The experimental part includes fabrication, material characterization and electrochemical testing of an EDLC with xGNP-750 coating electrodes and electrolyte 1M LiPF6 in EC:DMC. The computational part includes simulations of the galvanostatic charge-discharge of each EDLC type, based on a continuum ion transport model taking into account the PSD of electrodes, as well as molecular modeling to determine the parameters of the solvated and desolvated electrolyte ions and their adsorption energies with each type of electrode pore surface material. Predictions, in agreement with the experimental data, yield a specific electrode capacitance of 110 F g for xGNP-750 coating electrodes in electrolyte 1M LiPF in EC:DMC, which is three times higher than that of the high SSA a-MWGO coating electrodes in the same lithium ion electrolyte.
研究了用于含锂离子电解质的电化学双层电容器（EDLC）的石墨烯电极，重点是电极孔径分布（PSD）对溶剂化和去溶剂化电解质离子的影响。研究了两种石墨烯电极涂层：低比表面积（SSA）的xGNP - 750涂层和基于α - MWGO（活化微波膨胀氧化石墨烯）的高比表面积涂层。该研究包括实验和计算机建模两部分。实验部分包括制备、材料表征以及对带有xGNP - 750涂层电极和EC:DMC中1M LiPF6电解质的EDLC进行电化学测试。计算部分包括基于考虑电极PSD的连续离子传输模型对每种EDLC类型的恒电流充放电进行模拟，以及通过分子建模来确定溶剂化和去溶剂化电解质离子的参数及其与每种电极孔表面材料的吸附能。与实验数据一致的预测结果表明，在EC:DMC中的1M LiPF6电解质中，xGNP - 750涂层电极的比电容为110 F/g，这是相同锂离子电解质中高比表面积α - MWGO涂层电极比电容的三倍。
