Search

Two-dimensional (2D) composites with characteristics of high conductivity, good redox activity and large microporosity are constructed via sandwiching reduced graphene oxide (rGO) nanosheets with conjugated microporous polymers (CMPs) containing built-in redox-active ferrocene moieties. The integration of redox-active CMPs and conductive rGO within a 2D porous framework gives rise to remarkable faradaic energy storage as well as fast charge/energy transfer between the electrode and the electrolyte. As a result, the supercapacitors fabricated with these 2D hybrids possess remarkable capacitance at varied current density and excellent cycling stability. Thanks to the structural flexibility of CMPs, this strategy opens an avenue towards the design of new-generation supercapacitors and other electrochemical devices with molecular accuracy. [ABSTRACT FROM AUTHOR]

A high lithium conductive MoS 2 /Celgard composite separator is reported as efficient polysulfides barrier in Li-S batteries. Significantly, thanks to the high density of lithium ions on MoS 2 surface, this composite separator shows high lithium conductivity, fast lithium diffusion, and facile lithium transference. When used in Li-S batteries, the separator is proven to be highly efficient for depressing polysulfides shuttle, leading to high and long cycle stability. With 65% of sulfur loading, the device with MoS 2 /Celgard separator delivers an initial capacity of 808 mAh g -1 and a substantial capacity of 401 mAh g -1 after 600 cycles, corresponding to only 0.083% of capacity decay per cycle that is comparable to the best reported result so far. In addition, the Coulombic efficiency remains more than 99.5% during all 600 cycles, disclosing an efficient ionic sieve preventing polysulfides migration to the anode while having negligible influence on Li + ions transfer across the separator. The strategy demonstrated in this work will open the door toward developing efficient separators with flexible 2D materials beyond graphene for energy-storage devices., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)