Preparation and performances of LiFePO4 cathode in aqueous solvent with polyacrylic acid as a binder

Here we report the preparation of LiFePO4 cathode for lithium ion battery in the aqueous solvent with polyacrylic acid (PAA) as a binder. Its performances were studied by cyclic voltammetry(CV),charge-discharge cycle test, electrochemical impedance spectroscopy (EIS). X-ray diffraction (XRD), and scanning electron microscopy (SEM), and compared with the cathode prepared in N-methyl-2-pyrrolidone (NMP) solvent by using polyvinylidene fluoride (PVDF) as a binder. It is found that the cathode prepared in the aqueous solvent shows better performances than that in NMP solvent, including the better reversibility, the smaller resistances of solid electrolyte interphase and charge exchange, the less polarization. higher capacity and cyclic stability for lithium ion intercalation in or de-intercalation from LiFePO4. The aqueous solvent is also more environmental friendly and cheaper than NNP. In addition, PAA is less costly than PVDF. Consequently, the preparation of LiFePO4 cathode in the aqueous solvent by using a PAA binder provides lithium ion battery with improved performances at a less cost and in a more environmental friendly way. (c) 2008 Elsevier B.V. All rights reserved.