| δ-MnO2改性石墨烯气凝胶的制备及电化学性能 |
| Preparation and Electrochemical Performance of δ-MnO2/Graphene Aerogels For Li-Ion Batteries |
| 作者 | 单位 | E-mail | | 李治 | 中国矿业大学材料与物理学院, 徐州 221116 | | | 黄笑 | 中国矿业大学材料与物理学院, 徐州 221116 | | | 顾修全 | 中国矿业大学材料与物理学院, 徐州 221116
中国矿业大学江苏省高校储能技术与装备工程实验室, 徐州 221116 | xqgu@cumt.edu.cn | | 邢政 | 中国矿业大学材料与物理学院, 徐州 221116
中国矿业大学江苏省高校储能技术与装备工程实验室, 徐州 221116 | | | 赵宇龙 | 中国矿业大学材料与物理学院, 徐州 221116
中国矿业大学江苏省高校储能技术与装备工程实验室, 徐州 221116 | | | 强颖怀 | 中国矿业大学材料与物理学院, 徐州 221116
中国矿业大学江苏省高校储能技术与装备工程实验室, 徐州 221116 | yhqiang@cumt.edu.cn |
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| 摘要: 通过对还原石墨烯气凝胶（RGOA）进行δ-MnO2纳米颗粒改性制备出锂离子电池负极，并获得了良好的电化学性能。同时研究了δ-MnO2的负载量对三维复合RGOA/δ-MnO2负极材料电化学性能的影响，发现随着δ-MnO2负载量的增加，锂离子电池性能先增后减，在δ-MnO2负载量合适时（160 mg）比容量达到最大值（1 701.9 mAh·g-1），该值明显高于δ-MnO2负极的理论容量1 230 mAh·g-1。此外，该RGOA/δ-MnO2-160 mg负极即便在5 A·g-1的大电流下经历600次循环后仍能保持210.5 mAh·g-1的比容量。如此优异的电化学性能归因于RGOA的大比表面积和高导电性，以及δ-MnO2颗粒的高比容量和高催化活性。此外，三维石墨烯气凝胶中大量的孔洞有利于提供足够的空间负载超细δ-MnO2颗粒，避免了δ-MnO2在嵌锂过程中的体积膨胀以及抑制了固液界面保护膜（SEM）的加厚。通过计算赝电容对锂离子电池比容量的贡献，证实RGOA/δ-MnO2电极的充放电过程为赝电容行为所主导，这也是取得良好比容量和循环性能的另一重要原因。 |
| 关键词: 石墨烯 气凝胶 δ-MnO2 赝电容 锂离子电池 |
| 基金项目: 中央高校基本业务经费项目（No.2019ZDPY04）资助。 |
| Abstract: In this work, the Li-ion batteries (LIB) made with 3D network structure anodes were fabricated through incorporating ultrathin δ-MnO2 nanoparticles (NPs) into a reduced graphene oxide aerogel (RGOA), while KMnO4 was employed as a raw for preparing δ-MnO2. The influence of MnO2 adding amounts on the electrochemical performance of the obtained RGOA/δ-MnO2 composite electrode was investigated. As the MnO2 adding amount increased, the electrochemical performance of RGOA/δ-MnO2 was increased firstly and then decreased, reaching a maximum reversible capacity of 1 701.9 mA·g-1 at a suitable loading amount of MnO2, which is significantly higher than the theoretical capacity of δ-MnO2 (1 230 mAh·g-1). Besides, for the LIBs containing RGOA/δ-MnO2 anodes, a high capacity of 210.5 mA·g-1 remained even after 600 discharge-charge cycles at 5 A·g-1. The excellent performance of RGOA/δ-MnO2-160 mg can be attributed to the synergistic effect from large specific area and high conductivity of RGOA, as well as high theoretical capacity and small particle size of δ-MnO2. Furthermore, the 3D framework porous structure provided by RGOA makes it possible to wrap δ-MnO2 NPs, avoiding the volume expansion of δ-MnO2 and suppressing the thickening of solid electrolyte interphase (SEI) layer. By calculating the contributions from pseudocapacitance and diffusion-controlled process, it was demonstrated that the charge/discharge mechanism of the RGOA/δ-MnO2-160 mg anode was dominated by the pseudocapacitance process, which also facilitated achieving good rate performance and cyclic stability. |
| Keywords: graphene aerogels δ-MnO2 pseudocapacitance lithium-ion batteries |
| 投稿时间：2021-01-21 修订日期：2021-05-11 |
| 摘要点击次数: 1167 |
| 全文下载次数: 517 |
| 李治,黄笑,顾修全,邢政,赵宇龙,强颖怀.δ-MnO2改性石墨烯气凝胶的制备及电化学性能[J].无机化学学报,2021,37(7):1284-1294. |
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