Enhanced electrochemical behavior of Ni-doped MoO3 and reduced graphene oxide composite for lithium-ion batteries

• Synthesis of Ni doped MoO 3 and rGO composite via one pot hydrothermal technique and employed as an anode in LIBs half-cell. • Doping provides extra active redox sites, optimizing half-cell stability and Li +1 ion transportation. • Discharge specific capacity observed around 1380 mAh/g at a current density of 0.3 A/g with efficient charge transfer time of 0.0013 ms. • Exhibits enhanced capacity retention of 91.5% after 159 cycles, offers competent solution for high-performance LIBs applications. Owing to the enhanced theoretical specific capacity of molybdenum trioxide (MoO 3 ), it is a desirable anode material used in lithium-ion batteries (LIBs). The composite of 2% Ni-doped MoO 3 (Ni-MoO 3 ) and reduced graphene oxide (rGO) is synthesized to achieve higher cyclic stability. A hydrothermal method is used to prepare undoped MoO 3 /rGO (MoO 3 /rGO) and 2% Ni-doped into MoO 3 integrated with rGO (Ni-MoO 3 /rGO) composite. X-ray diffraction (XRD) confirms the successful synthesis of the composite by showing the diffraction planes of MoO 3 and rGO. Raman spectroscopy exhibits the efficacious formation of composites by showing the MoO 3 and carbon vibrational modes. Scanning electron microscopy (SEM) shows MoO 3 nanosheet integrated with rGO matrix. X-ray Photoelectron Spectroscopy (XPS) confirms the proper substitution of cationic (Ni +2 ) ions into the MoO 3 lattice with reasonable chemical shift in binding energy due to the change of electronic states. Cyclic voltammetry (CV) measurements of coin cell showed dominant anodic and cathodic peaks at 2 mV/s near 1.49 V and 1.14 V, respectively. At 10 mV/s, capacitive behavior is obtained in response to high voltage rate. At 0.3 A/g, Ni-MoO 3 /rGO showed discharge specific capacity of 1380 mAh/g which is 55.8 % (609 mAh/g) higher than the MoO 3 /rGO. Furthermore, Ni-MoO 3 /rGO composite retains capacity of 91.5% after 159 cycles whereas MoO 3 /rGO composite shows retention of 71.3% after only 100 cycles. Ni-MoO 3 /rGO anode material exhibits exceptional behavior over other conventional materials due to its stable crystal structure, faster reaction kinematics and improvement in specific capacity. rGO is responsible for maintaining structural stability during lithiation/de-lithiation, MoO 3 enhances specific capacity, while Ni +2 doping improves reaction kinematics which overcome the problems currently faced by LIBs industry. This paper emphasizes overcoming the current problems related to the LIBs industry.