ZIF-67 Derived Hollow Co9S8 as an Efficient Polysulfides Prohibitor for High Performance Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) have received great attention due to their large energy density and specific capacity. Unfortunately, the poor cycle stability due to the shuttle effect of soluble polysulfides seriously impedes the application of LSBs. In order to solve this problem, we report the synthesis of ZIF-67 derived hollow Co9S8 which is coated on the commercial separator for LSBs through a self-template strategy. The hollow structure Co9S8 can capture a large amount of polysulfides during cycling, and the polar Co9S8 can chemically adsorb and catalyze the reaction intermediate, greatly reducing the migration of polysulfides. As a result, the hollow Co9S8 modified separator exhibits good rate performance and remains a capacity of 540.5 mAh g(-1) after 500 cycles at 0.5 C as the sulfur area density of 3.0 mg cm(-2). Even when the sulfur area density is increased to 5.0 mg cm(-2), the battery using hollow Co9S8 modified separator still exhibits good cycle property.

Automated summary

The synthesis of hollow Co9S8 coated on commercial separator for lithium-sulfur batteries using a self-template strategy is reported, which can effectively capture and reduce the migration of polysulfides, leading to improved cycling stability and rate performance.