lithium-ion batteries (LIBs) have proven an unprecedented success in portable electronics, electric vehicles, grid storage, etc., which make a great difference in our lives. Hence, the 2019 Nobel Prize in Chemistry was awarded to John B. Goodenough, M. Stanley Whittingham, and Akira Yoshino for their revolutionary work in the field of LIBs. [1] The current LIBs technology is based on insertion-compound anode and cathode materials. As shown in Figure 1, the capacities of the insertion-oxide cathodes have reached the limit of ≈250 mAh g −1 , and that of the graphite anode is also limited to ≈370 mAh g −1 . However, the limited capacities are unable to satisfy the ever-growing need for gravimetric and volumetric energy density. It is required topic to develop next generation energy technology. Targeting the goal, researchers have their sights set on alternative electrode materials. On the anode side, based on conversion reactions while accommodating more ions and electrons are becoming promising options. [2] Approaching mature silicon/ carbon anode elevates anode capacity well. [3] And lithium metal anode are also booming. [4] On the cathode side, multi-electron conversion reaction represented by sulfur and oxygen electrode can offer capacities exceed that of conventional insertion cathodes, such as, LiCoO 2 and LiMn 2 O 4 , by an order of magnitude (>1500 mAh g −1 ). Since 2009, lithium-sulfur (Li-S) batteries have received increasing attention and are considered as one of the most promising candidates for next-generation rechargeable batteries after the development of high-performance Li-S batteries by CMK-3 as host. [5] Sulfur, as one of the most abundant elements on earth, is an electrochemically active material that can accept two electrons per atom at ≈2.1 V (vs. Li + /Li). [6] As a result, sulfur cathode materials have high theoretical capacity of 1675 mAh g −1 , and Li-S batteries have theoretical energy density of ≈2600 Wh kg −1 . [7] However, the issues including low conductivity of S and Li 2 S, shuttle effect, large volumetric expansion, and unstable lithium metal anode have to face. [8] Up to now, intensive efforts in component regulation and structure engineering electrode materials have been focused on solving these issues.Sulfur cathodes with high sulfur content (>90 wt%), [9] excellent cycling life (>3000 cycles), [10] as well as, high operating Lithium-sulfur (Li-S) batteries, with high theoretical energy density, promise to be the optimal candidate of next-generation energy-storage. Rapid development in materials has made a major step forward in Li-S batteries. However, a big gap in cycle life and efficiency for practical applications still remains. Reasonable design of materials/electrodes a is significant aspect that must be addressed. The rising metal-organic frameworks (MOFs) are a new class of crystalline porous organic-inorganic hybrid materials. Abundant inorganic nodes and designable organic linkers allow tailored pore chemistry at a molecular-scale, which enables tunable interaction w...
