| Power type lithium ion battery is a crucial part of the future electric vehicle technology, titanium dioxide has a great potential as power type lithium ion battery cathode material. Ti O2 has a very small volume strain when it intercalates Li, it also has a high platform voltage and do not form solid electrolyte interface. But it lacks enough electrical conductivity, this limits the diffusion of lithium ions and electrons conduction, which makes it have a very large capacity loss and a bad cycling stability.Nanoparticles Ti O2 has a better conductivity and a better diffusion of lithium ions. The main content of this paper is that we have prepared the nanoparticles titanium dioxide material by doping transition metal to improve the materials specific capacity and cycle performance.In this paper, we have prepared the transition metal Co2+ doped and Fe2+ Co2+ doped nanoparticles anatase Ti O2 materials by the transition metal salt and tetra–n-butyl titanate. Then we made the prepared material a heat treatment under different temperature. The prepared material has a very small particle size and uniform particle size distribution. The Co2+ doped materials under 600℃ heat treatment has the longest discharge platform. the Co2+ doped materials of under 300℃ heat treatment has the biggest first discharge capacity at 0.1C, 350 m Ah/g. The Fe2+ Co2+ doped materials under 600℃ heat treatment has a initial discharge capacity of 445 m Ah/g at 0.1C, but capacity attenuation is very large.We also use four tetra-n-butyl titania as the titanium source and 2-ethylimidazole as the reductant preparing the Ti3+ doped Ti O2 by part reduction. The prepared materials has a better electrical conductivity and a better electrochemical performance. It has a discharge capacity of 130 m Ah/g at 1C. We also prepared the Ti3+ doped P25 by a simple vacuum activation method, the conductivity of the material is also improved. But the electrochemical properties of Ti3+ doped P25 is worse than the nano anatase materials. |
PDF Full Text Request