In this study, nickel molybdate nanosphere agglomerates with enhanced electrochemical performance were prepared using a rapid, time-saving, and scalable microwave combustion method by doping with different concentrations of La, and the effect of dopants on their structural, morphological, and electrochemical properties were investigated. Structural analyses demonstrated that the La dopant influenced the phase transformation from α-to β-NiMoO4. The electrochemical behaviors of all samples were tested in 3 M KOH electrolyte. The maximum specific capacitance obtained for 5% La doped NiMoO4 was 1264.64 F g−1 at 1 mA cm−2, which was almost 2.6 times higher than that for the pristine NiMoO4. The higher specific capacitance may have been due to the larger active surface area and greater abundance of reactive sites which depends on the morphological characteristics. A device fabricated with the 5% La doped sample had a maximum specific capacitance of 92.1 F g−1 and an energy density of 25.1 Wh kg−1 at 1 mA cm−2. The power density of the device was 5.3 kW kg−1 at a high current density of 25 mA cm−2, and 81.74% was retained after 10,000 cycles, thereby demonstrating the great potential for using this material in high-end energy storage applications. Display omitted •Lanthanum doped Nickel molybdate has been successfully prepared by microwave combustion method.•Phase transfer from α to β phase-NiMoO4 has been observed while increasing dopant concentration.•5% La–NiMoO4 revealed high Csp of 1264.64 F g−1 at 1 mA cm−2 with good retentivity of 98.86% after 5000 cycles.•FLN//AC device displayed a high energy and power density of 25.1 W h kg−1 and 5.83 kW kg−1.