TiO2-based microsphere with large pores to improve the electrochemical performance of Li-ion anodes

A microsphere composed of nano-TiO₂ and carbon with a large pore size was constructed, and its potential as the anode active material for lithium-ion batteries was explored. The pores can promote the intake of the liquid electrolyte by the microsphere, improving the transport of electrons and ions, and the carbon surrounding the nano-TiO₂ in the skeleton of the microsphere can decrease the electronic resistance. At low charge/discharge rates of 0.5–2C, the cell made of the porous microspheres exhibited better stability of capacity—from low capacity retention of less than 70% to greater than 88% after 200 cycles—than the cell made of the as-received nano-TiO₂. At high rates of 5–10C, the capacity of the cell made of the as-received nano-TiO₂ was contributed mainly by the capacitance effect. In contrast, the capacity of the cell made of the porous microspheres was contributed mainly by the electrochemical lithiation/delithiation, resulting in a higher capacity with good stability for at least 1000 cycles.