Carbon-Free, High-Capacity and Long Cycle Life 1D-2D NiMoO₄ Nanowires/Metallic 1T MoS₂ Composite Lithium-Ion Battery Anodes

Both metallic 1T MoS₂ and conductive molybdate compounds exhibit interesting electrochemical properties, however, the properties of composite electrodes based on these materials have not been investigated. Here, 1T MoS₂ single crystal nanosheets and NiMoO₄ single crystal nanowires are synthesized and formed into a carbon-free composite lithium-ion anode using blade- and spray-coating. The composite anodes deliver charge mass specific capacity of 940.1 mAh g^-1, while the discharge mass specific capacity is up to 941.6 mAh g^-1, with a capacity retention ratio of 84.2% after 750 cycles. The charge and discharge volumetric capacity (porosity of 15.6%, full electrode basis, excluding the current collector) are 1238.7 mAh cm^-3 and 1240 mAh cm^-3, respectively, and the active materials volume fraction is 82.5%. These capacities significantly exceed that of single 1T MoS₂ or single NiMoO₄ anodes we reported. We calculate if matched vs a cathode with an average discharge voltage of 4.0 V the gravimetric energy density of the composite electrodes would be 3389.8 Wh kg^-1. Electrochemical measurements indicate that the composite electrode has excellent electrochemical reversibility, suggesting that the structure has played a crucial role in the cycling process.