Synthesis of Ni_xCo_(1−x)F₂ (x = 0, 0.25, 0.50, 0.75, 1.0) and application in lithium ion batteries

In this work, Ni_xCo_(1−x)F₂ with x = 0, 0.25, 0.5, 0.75 and 1.0 have been successfully synthesized. A specific discharge capacity of 700 mAhg⁻¹ and recharge capacity of 482 mAhg⁻¹ was delivered by Ni_0.75Co_0.25F₂ in the first cycle. Our electrochemical results in lithium half-cell have shown that nickel containing fluorides have a higher discharge voltage, higher experimental discharge specific capacities and smaller hysteresis between the discharge and charge reactions as compared to pure cobalt fluoride. In addition, this work also presents a method to tune the discharge voltage and eliminate the voltage delay effect commonly observed in metal fluorides via the use of solid solution. - Highlights: • Synthesis of nanoparticles of Ni_xCo_(1−x)F₂ with x = 0.25, 0.50, 0.75. • Electrochemical performance of Ni_xCo_(1−x)F₂ (x = 0.25, 0.50, 0.75). • Use of solid solution to tune the discharge voltage of conversion materials.