This article reports the use of crystalline nickel phosphate/carbon fibres (NiPh/CFs) nanocomposite as an electrode material for pseudocapacitor applications. The NiPh particles are synthesised by a cost-effective one-pot method, which is based on refluxing nickel and phosphate precursors at 90 degrees C. The crystallinity and structural morphologies of the synthesised particles are characterised by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). Also, the N-2 adsorption/desorption isotherms are recorded. The Brunauer-Emmett-Teller (BET) method is used to calculate the specific surface area. The electrochemical performances of pristine NiPh and NiPh/CFs composite electrodes are investigated in an alkaline solution of 0.5M of KOH. The specific capacitances were calculated using cyclic voltammograms at a potential scan rate of 100mV s(-1). For the pristine electrode, the calculated specific capacitance was 4.3F g(-1) and for the composite NiPh/CFs electrode, it was 699.2F g(-1). The significant improvement in the performance is attributed to the high surface area and enhanced electronic conductivity of the NiPh/CFs composite electrode. Also, the composite electrode shows outstanding stability and delivers 1000 cycles with excellent capacitance retention.Graphical abstractA cost-effective material for high-performance pseudocapacitors: Crystalline NiPh nanoparticles have been synthesised at 90 degrees C. SEM image shows the pseudocapacitors composite electrode fabricated by mixing the NiPh with CFs. The electrode delivers a specific capacitance of 699.2 F g(-1); calculated from the cyclic voltammogram shown in the figure. Also, the composite electrode shows good stability and provides 1000 cycles with excellent capacitance retention. [GRAPHICS] .