Affiliation:
1. Department of Materials Science and Engineering College of Aerospace Science and Engineering National University of Defense Technology Changsha 410000 P. R. China
2. Henan International Joint Laboratory of Rare Earth Composite Materials College of Materials Engineering Henan University of Engineering Zhengzhou 450000 P. R. China
Abstract
AbstractA practical and effective approach to improve the cycle stability of high‐energy density lithium metal batteries (LMBs) is to selectively regulate the growth of the lithium anode. The design of desolvation and lithiophilic structure have proved to be significant means to regulate the lithium deposition process. Here, a fluorinated polymer lithiophilic separator (LS) loaded with a metal–organic framework (MOF801) is designed, which facilitates the rapid transfer of Li+ within the separator owing to the MOF801‐anchored PF6− from the electrolyte, Li deposition is confined in the plane resulting from the polymer fiber layer rich in lithiophilic groups (C─F). The numerical simulation results confirm that LS induces a uniform electric field and Li+ concentration distribution. Visualization technology records the behavior of regular Li deposition in Li||Li and Li||Cu cells equipping LS. Therefore, LS exhibits an ultrahigh Li+ transference number (tLi+ = 0.80) and a large exchange current density (j0 = 1.963 mA cm−2). LS guarantees the stable operation of Li||Li cells for over 1000 h. In addition, the LiNi0.8Co0.1Mn0.1O2||Li cell equipped with LS exhibits superior rate and cycle performances owing to the formation of LiF‐rich robust SEI layers. This study provides a way forward for dendrite‐free Li anodes from the perspective of separator engineering.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Henan Province
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science