Effects of Fibrous Nickel Additives on the Electrochemical Properties of LiFePO₄ Cathode for Lithium-ion Battery

摘要

In this paper, the effects of fibrous nickel(Ni) additives on the electrochemical performance ofLiFePO4 as a lithium-ion battery cathode were investigated by a simple mixing process of LiFePO4powders and porous nickel fibers. The microstructure and crystalline phase were characterized byscanning electron microscopy (SEM) and X-ray diffractometry (XRD). The electrochemical propertiesof nickel fiber/LiFePO4 composite were analyzed by the electrochemical impedancespectroscopy(EIS), cyclic voltammetry(CV), and galvanostatic charge/discharge test. Highlyconductive Ni additive can enhance the electronic conductivity of LiFePO4. Electrode fabricated fromnickel fiber/LiFePO4 composite as lithium-ion battery cathode exhibits better electrochemicalperformance compared with pristine LiFePO4. The electrode with optimal fiber content of 10wt% has-1the best redox kinetics and possesses a good rate capability of 85 mAh g even at 5C, versus 60 mAh-1 -1g for pristine LiFePO4. It also shows good cyclability with initial discharge capacity of 131.1 mAh g -1 at 1C, and the retention capacity of 119.8 mAh g after 100 cycles, whereas pristine LiFePO4 only-1 -1 delivers 108.2 mAh g at the same condition and retention capacity of 100.9 mAh g after 100 cycles.