Conducting polymer-functionalized mesoporous metal-organic frameworks for high-performance Li-S battery

It was known that mesoporous metal-organic frameworks (MOFs) with hierarchical pores and unsaturated metal sites can effectively inhibit the shuttle effect of lithium polysulfides in lithium-sulfur battery, however, the unsatisfactory structural stability and electrical conductivity limit the application of mesoporous MOFs (MMOFs) in Li-S batteries. Aiming at sensible solutions, the conductive polyaniline (PANI) was incorporated into the MMOF to enhance the discharge capacity and the cycling stability of proposed Li-S batteries, as the stability and the conductivity of the MMOF cathode was improved simultaneously. The activated MMOF-PANI provides physical and chemical adsorption of polysulfides against their shuttle effect. Moreover, the introduction of PANI into the channels of MMOF effectively improves the conductivity of MMOF, thus improving the electrochemical performance of the MMOF-PANI-based batteries. Benefiting from these synergetic effects, the S@MMOF-PANI cathode delivers improved electrochemical performance including excellent rate performance and cycling stability. The battery shows an initial capacity of 777.7 mAh·g−1 at 2.0 C and a low decay rate of 0.06% per cycle in 1,000 cycles and approximately a repeatable rate performance.