Effect of NI-Doping on Electrochemical Performance of Olivine LiFe1-XNixPO4 for Sodium-Ion Batteries

Abstract

In 21th century, rechargeable batteries are main key of modern technology in many applications from portable devices (smartphone, laptop…) to large-scale (hydride electric vehicle-HEV, smart grid system…). Among the rechargeable batteries, Li-ion battery (LIB) is outstanding member due to the highest gravimetric as well as volumetric capacity; and Sodium-ion batteries (SIBs) can have contribution to alternating LIBs in large-scale application. Li-ion and Na-ion batteries have the same configuration with an insertion/extraction reversible of Li+ ions and Na+ ions into electrode positive and negative during charge-discharge process. This work aimed to investigate the effect of Ni-doping on the electrochemical performance of olivine LiFePO4 in sodium secondary batteries. The Ni-doping olivines LiFe1-xNixPO4 (0 < x ≤ 0.25) were prepared by hydrothermal route which exhibited a high crystallization and good distribution grains in nanometric scale. The delithiated phases Fe1-xNixPO4 were obtained by the electrochemical oxidation at rate C/20. In charge-discharge profile in Na-cell, a specific capacity was found out 125 mAh/g with a capacity retention of 95% after 50 cycles.