杂原子
多硫化物
掺杂剂
电负性
材料科学
法拉第效率
密度泛函理论
阴极
合理设计
纳米技术
硫黄
锂(药物)
化学物理
电解质
兴奋剂
碳纤维
电化学
化学工程
化学
计算化学
有机化学
物理化学
光电子学
电极
复合材料
冶金
内分泌学
工程类
复合数
医学
戒指(化学)
作者
Thomas Y. Hou,Xiang Chen,Hong‐Jie Peng,Jia‐Qi Huang,Bo‐Quan Li,Qiang Zhang,Bo Li
出处
期刊:Small
[Wiley]
日期:2016-05-11
卷期号:12 (24): 3283-3291
被引量:663
标识
DOI:10.1002/smll.201600809
摘要
Lithium-sulfur (Li-S) batteries have been intensively concerned to fulfill the urgent demands of high capacity energy storage. One of the major unsolved issues is the complex diffusion of lithium polysulfide intermediates, which in combination with the subsequent paradox reactions is known as the shuttle effect. Nanocarbon with homogeneous nonpolar surface served as scaffolding materials in sulfur cathode basically cannot afford a sufficient binding and confining effect to maintain lithium polysulfides within the cathode. Herein, a systematical density functional theory calculation of various heteroatoms-doped nanocarbon materials is conducted to elaborate the mechanism and guide the future screening and rational design of Li-S cathode for better performance. It is proved that the chemical modification using N or O dopant significantly enhances the interaction between the carbon hosts and the polysulfide guests via dipole-dipole electrostatic interaction and thereby effectively prevents shuttle of polysulfides, allowing high capacity and high coulombic efficiency. By contrast, the introduction of B, F, S, P, and Cl monodopants into carbon matrix is unsatisfactory. To achieve the strong-couple effect toward Li2 Sx , the principles for rational design of doped carbon scaffolds in Li-S batteries to achieve a strong electrostatic dipole-dipole interaction are proposed. An implicit volcano plot is obtained to describe the dependence of binding energies on electronegativity of dopants. Moreover, the codoping strategy is predicted to achieve even stronger interfacial interaction to trap lithium polysulfides.
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