posted on 2022-02-02, 14:08authored byYan Yang, Shiyan Yao, Ziwei Liang, Yucheng Wen, Zhengbo Liu, Yiwen Wu, Jun Liu, Min Zhu
Covalent
organic frameworks (COF) displayed strong affinity between
COF and Li+ in terms of previous works. However, the relationship
of COF and solvent molecules in the electrolyte was exclusive. Herein,
a self-supporting COF separator (TPB-BD(OH)2-COF) was synthesized
and served as a separator in lithium metal batteries. The formation
of hydrogen bond network is due to the interaction of hydroxyl functional
group (−OH) in TPB-BD(OH)2-COF and −OH···F
and −OH···O in PF6–, EC and EMC within solvent sheath to achieve the desolvation process
and realize more aggregative electrolyte, thus reducing the free solvent
and lithium metal side effects. Therefore, the full cell assembled
with self-supporting COF displayed superior cycling stability with
a reversible capacity of 114.3 mAh g–1 after 335
cycles at a current density of 1C and a capacity of 5 mAh cm–2. Moreover, the COF separator can perform well even in extreme environments
(temperature 60 °C).