Nitrogen-doped graphene ribbons/MoS2 with ultrafast electron and ion transport for high-rate Li-ion batteries

Nanostructured molybdenum sulfide (MoS2) is considered as a promising Li-ion batteries anode material with high capacity due to its four-electron transfer reaction. However, the two-dimensional (2D) sheets tend to aggregate during the process of electrode preparation and subsequent charging/discharging, severely limiting the electron and ion transport. Particularly, as the mass loading (or thickness) of the electrode increases, it is extremely hard to achieve proper performance for MoS2 based anode materials. Here, we report a strategy to solve these problems by anchoring the few-layers MoS2 on the nitrogen-doped graphene ribbons with the assistance of multifunctional groups (-SH, -NH2, and -COO−). Compared with pure MoS2, the MoS2 anchored on nitrogen-doped graphene ribbons (N-GRs/MoS2) can deliver much better cycling stability (92.6% capacitance retention after 600 cycles), higher reversible capacity (1151 mAh g−1 at 0.1 A g−1), and more satisfying rate performance (499.3 mAh g−1 at 8.0 A g−1). More importantly, the specific capacitance of N-GRs/MoS2 is less dependent on the electrode mass loading (1151 mAh g−1 at 1 mg cm−2 vs. 1000 mAh g−1 at 5 mg cm−2). Moreover, with the N-GRs/MoS2 and lithium iron phosphate (LFP) as anode and cathode, respectively, the N-GRs/MoS2//LFP full cell can achieve a maximum specific energy of 359.8 Wh kg−1 at 81.7 W kg−1, and a capacity retention of 86% after 200 cycles.