分离器(采油)
成核
化学工程
催化作用
电化学
电导率
材料科学
蒸发
掺杂剂
溶解
化学
纳米技术
无机化学
兴奋剂
电极
物理化学
有机化学
热力学
光电子学
物理
工程类
作者
Shaoming Qiao,Da Lei,Qian Wang,Xiaoshan Shi,Qiang Zhang,Chunhong Huang,Anmin Liu,Gaohong He,Fengxiang Zhang
标识
DOI:10.1016/j.cej.2022.136258
摘要
Excellent specific discharge capacity and cycling stability are essential for high-performance lithium-sulfur (Li-S) batteries, but hard to achieve simultaneously due to the shuttle effect and sluggish reaction kinetics of polysulfides. Herein, we report an etch-evaporation enabled defect engineering strategy to fabricate atomically dispersed, manganese-nitrogen doped porous carbon (Mn-N-C) for separator modification. With Zinc atoms evaporation and NH3 etch, abundant spatial confinement sites and N dopants are created in Mn-N-C, and the final Mn loading can reach as high as 2.31 wt%. Density function theory (DFT) calculations reveal that Mn atoms in Mn-N-C play a crucial role in polysulfides adsorption and electrical conductivity enhancement. Therefore, the Mn-N-C modified separator can exhibit high conductivity, strong immobilization and excellent catalytic activity, thus favoring polysulfides conversion and Li2S nucleation/dissolution. The Li-S battery equipped with the modified separator exhibits an initial discharge capacity of 1596 mAh g−1 at 0.1C (S loading mass was 1.2 mg cm−2), which decays 0.045 % per cycle after 1000 cycles at 1C. Our work demonstrates that the etch-evaporation enabled defect engineering strategy is effective for fabrication of high-performance Li-S battery catalyst; it also shows an attractive prospect to synthesize other high loading metal ion dispersed, nitrogen doped carbon materials for electrochemical applications.
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