Dopant-Modulating Mechanism of Lithium Adsorption and Diffusion at the Graphene/Li2S Interface

作者：Guo, Lichao; Li, Jiajun^*; Wang, Huayu; Zhao, Naiqin; Shi, Chunsheng; Ma, Liying; He, Chunnian; He, Fang; Liu, Enzuo^*

来源：Physical Review Applied, 2018, 9(2): 024010.

DOI：10.1103/PhysRevApplied.9.024010

• DOPED GRAPHENE
• ANODE MATERIALS
• ASSISTED SYNTHESIS
• ION
• SULFUR
• CATHODE
• MOS2
• NANOCOMPOSITES
• BATTERIES
• CAPACITY

Graphene modification is one of the most effective routes to enhance the electrochemical properties of the transition-metal sulfide anode for Li-ion batteries and the Li2S cathode for Li-S batteries. Boron, nitrogen, oxygen, phosphorus, and sulfur doping greatly affect the electrochemical properties of Li2S/graphene. Here, we investigate the interfacial binding energy, lithium adsorption energy, interface diffusion barrier, and electronic structure by first-principles calculations to unveil the diverse effects of different dopants during interfacial lithiation reactions. The interfacial lithium storage follows the pseudocapacitylike mechanism with intercalation character. Two different mechanisms are revealed to enhance the interfacial lithium adsorption and diffusion, which are the electron-deficiency host doping and the vacancylike structure evolutions with bond breaking. The synergistic effect between different dopants with diverse doping effects is also proposed. The results give a theoretical basis for the materials design with doped graphene as advanced materials modification for energy storage.

• 出版日期2018-2-9
• 单位天津大学