Enhanced electrochemical properties of LiFePO4 cathode for Li-ion batteries with amorphous NiP coating

✍ Scribed by Gui-Ming Song; Ying Wu; Qiang Xu; Gang Liu

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 818 KB
• Volume: 195
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2009.12.089

✦ Synopsis

Here we show that the intrinsic low electrical conductivity of LiFePO 4 which seriously hinders the application of LiFePO 4 for Li-ion batteries is overcome with conductive metallic NiP nano-coating. High resolution transmission electron microscopy image reveals that the NiP coating is a nanoscale amorphous layer, which was deposited on the LiFePO 4 particles to form a so-called core/shell structure via electroless plating at room temperature. The electrochemical performances of NiP coated LiFePO 4 show that both of the rate performance and cycleability of LiFePO 4 against graphite anode are improved by the NiP coating. Analysis of electrochemical impedance spectra of the LiFePO 4 /graphite cells demonstrates that the NiP coating decreases both of the surface film resistance and charge transfer resistance. The dissolution of Fe from LiFePO 4 in the LiPF 6 based electrolyte is remarkably suppressed by the protective NiP coating.