Polyoxovanadate (NH4)7[MnV13O38] as cathode material for lithium ion battery and improved electrochemical performance
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Highpower International Inc., Shenzhen 518111, China)
2. Highpower International Inc., Shenzhen 518111, China)
Abstract: The polyoxovanadate (NH4)7[MnV13O38] (AMV) was synthesized and characterized by X-ray diffraction pattern, Fourier transform infrared spectra, and field emission scanning electron microscope equipped with energy dispersive X-ray spectroscopy. In order to improve the electrochemical performance of AMV, the particle size of as-prepared AMV is decreased to nanoscale by re-precipitation in the water-ethanol solution. The results of the electrochemical impedance spectra and the 4-pin probe measurements show that the electrical conductivity of AMV is improved by decreasing the particle size. The nanoparticle AMV shows higher initial discharge capacity and energy density than the as-prepared AMV when cycled at 0.5C. On the other hand, the nanoparticle AMV exhibits higher rate capability than the as-prepared AMV.
Key words: lithium ion battery; cathode material; polyoxovanadate; nanoparticle