Stabilizing sulfur cathodes using nitrogen-doped graphene as a chemical immobilizer for Li-S batteries

摘要

Lithium-sulfur (LieS) battery, as a high energy-density storage system, has attracted great attention for next generation rechargeable battery applications. However, the fast capacity decay caused by lithium polysulfides (LiPSs) dissolution impedes its prospect for commercialization. In this work, nitrogen-doped graphene, as a chemical immobilizer, was designed to bind LiPSs and stabilize sulfur in the cathode for high performance LieS batteries. The incorporated nitrogen dopants in the graphene network were found to have a strong binding effect on the LiPSs to improve electrochemical stability and promote fast electrochemical reaction kinetics. As a result, the nitrogen doped graphene-based sulfur electrode could deliver an initial capacity of similar to 1200 mAh g(-1) at 0.3 A g(-1), and exhibit good capacity retention with only 0.05% capacity decay per cycle after 300 cycles at 0.75 A g(-1). (C) 2016 Elsevier Ltd. All rights reserved.