Pomegranate-like MoC@C composites as stable anode materials for lithium-ion batteries

Transition metal carbides serving as anode materials for lithium-ion batteries attract increasing attention owing to their high capacity and excellent conductivity. In this article, pomegranate-like granules assembled by carbon coated molybdenum carbide nanocrystallites (MoC@C) are fabricated through facile carburization of metal-organic framework precursor of trimesic acid Molybdenum (Mo-3(BTC)(2)). The pomegranate-like structure not only offers short diffusion paths for Li+, but also relieves the volume variations during the Li+ insertion/extraction process. The size of MoC nanocrystallites and the content of carbon coating can be optimized by adjusting the carburization temperature. The optimal MoC@C-700 sample exhibits superior cycle stability and high-rate performance. At 200 mA g(-1), it shows reversible capacity of 647.3 mAh g(-1). Even when the current density increases to 1 A g(-1), it still delivers 570.6 mAh g(-1) in the first cycle and maintains 509.8 mAh g(-1) after 500 cycles. The high capacity and stable cycling performance indicate the pomegranate-like MoC@C composites may be promising for high-performance lithium-ion batteries anode. (C) 2019 Published by Elsevier B.V.