Improved rate capability of carbon coated Li3.9Sn0.1Ti5O12 porous electrodes for Li-ion batteries

A new sol–gel process is developed to modify the Li4Ti5O12 anode material for improved rate capability. The new process brings about the following effects, namely (i) doping of Sn2+ to form Li3.9Sn0.1Ti5O12, (ii) carbon coating and (iii) creation of a porous structure. The doping of Sn2+ results in the lattice distortion without changing the phase composition. A thin layer of amorphous carbon is coated on the doped particles that contain numerous nanopores. The rate capability of the anode material made from the modified powder is significantly improved when discharged at high current rates due to the reduced charge transfer resistance.

► Doping of Sn2+ is adopted to increase the conductivity of Li4Ti5O12.
► A thin layer of amorphous carbon is coated on the particle.
► Numerous nanopores are present on the surface of doped particle.
► Rate capability of Li4Ti5O12 are highly improved.