Defects Engineering of Lightweight Metal–Organic Frameworks-Based Electrocatalytic Membrane for High-Loading Lithium–Sulfur Batteries
Sha Li, Jiande Lin, Yu Ding, Pan Xu, Xiangyang Guo, Weiming Xiong, De‐Yin Wu, Quanfeng Dong, Jiajia Chen, Li Zhang
Abstract
The sluggish kinetics and shuttle effect of lithium polysulfide intermediates are the major issues that retard the practical applications of lithium–sulfur (Li–S) batteries. Herein, we introduce a defect engineering strategy to construct a defected-UiO-66-NH2-4/graphene electrocatalytic membrane (D-UiO-66-NH2-4/G EM) which could accelerate the conversion of lithium polysulfides in high sulfur loadings and low electrolyte/sulfur (E/S) ratio Li–S batteries. Metal–organic frameworks (UiO-66-NH2) can be directionally chemical engraved to form concave octahedra with abundant defects. According to electrocatalytic kinetics and DFT calculations studies, the D-UiO-66-NH2-4 architecture effectively provides ample sites to capture polysulfides via strong chemical affinity and effectively delivers electrocatalytic activity of polysulfide conversion. As a result, a Li–S battery with such an electrocatalytic membrane delivers a high capacity of 12.3 mAh cm–2 (1013 mAh g–1) at a sulfur loading up to 12.2 mg·S cm–2 under a lean electrolyte condition (E/S = 5 μL mg–1-sulfur) at 2.1 mA cm–2 (0.1 C). Moreover, a prototype soft package battery also exhibits excellent cycling stability with a maintained capacity of 996 mAh g–1 upon 100 cycles.