• 文献标题:   A Three-Dimensional Carbon Framework Constructed by N/S Co-doped Graphene Nanosheets with Expanded Interlayer Spacing Facilitates Potassium Ion Storage
  • 文献类型:   Article
  • 作  者:   YANG WX, ZHOU JH, WANG S, WANG ZC, LV F, ZHANG WS, ZHANG WY, SUN Q, GUO SJ
  • 作者关键词:  
  • 出版物名称:   ACS ENERGY LETTERS
  • ISSN:   2380-8195
  • 通讯作者地址:   Peking Univ
  • 被引频次:   7
  • DOI:   10.1021/acsenergylett.0c00413
  • 出版年:   2020

▎ 摘  要

Carbon nanomaterials show potential in achieving good potassium ion storage; however, the limited interlayer spacing in existing carbon nanomaterials greatly impacts the performance of potassium ion batteries (PIBs). Herein, we report a class of three-dimensional (3D) porous carbon framework materials constructed by S/N co-doping graphene nanosheets (CFM-SNG) with an ultralarge interlayer spacing (0.448 nm) and a rich edge defect as high-performance PIBs anodes. The resulting 3D CFM-SNG material achieves enhanced reversible capacity (348.2 mAh/g at 50 mA/g), cycling performance (188.8 mAh/g at 1000 mA/g after 2000 cycles), and rate capability (204.3 mAh/g at a high current density of 2000 mA/g). Density functional theory calculations further demonstrate that the S/N co-doping and formed edge defects not only favor the interlayer spacing expansion and the adsorption of K+ to the 3D CFM-SNG anode but also prevent variation in volume during the potassiation/depotassiation process.