Interconnected MoO2/MoS2@NC nanosheets as anodes with high-rate and long-life for lithium-ion and sodium-ion batteries

The development of sustainable and cost-effective anode materials with the ability to achieve superior performance in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) continues to pose a major challenge. Among the various available options, molybdenum-based materials have emerged as highly promising anodic candidates for both LIBs and SIBs owing to their substantial specific capacity, rapid electrochemical dynamics, and outstanding electronic conductivity. In this work, we present the preparation of molybdenum dioxide/molybdenum disulfide@nitrogen-doped carbon nanosheets (MoO2/MoS2@NC) via air-thermal activation. We highlight their exceptional lithium and sodium storage capabilities, which originate from their intricate hierarchical structures. As a result, the MoO2/MoS2@NC-15 composite has a remarkably high specific capacity (1027 mAh g−1 after 100 cycles at 100 mA g−1), high rate capability (490 mAh g−1 at 15000 mA g−1), and excellent cycling performance (618 mAh g−1 after 2000 cycles at 800 mA g−1) in LIBs. Moreover, in SIBs, the reversible specific capacity remaining is 246 mAh/g after 200 cycles at 600 mA g−1, which is indicative of a minimal capacity decrease of 0.4 mAh/g per cycle. Furthermore, comprehensive investigations were conducted on full cells comprising LIBs (MoO2/MoS2@NC-15//LiFePO4) and SIBs (MoO2/MoS2@NC-15//NaNi1/3Fe1/3Mn1/3O2), demonstrating their high specific capacities and excellent cycling performance. This study might provide a viable pathway toward developing straightforward and universally applicable synthesis methods for cutting-edge electrode materials in energy storage systems.