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Titanium niobium oxide (TiNb2O7) has received a great deal of attention in lithium-ion battery (LIBs) because of its high theoretical capacity, environmentally benign nature, and good cycling stability. However, TiNb2O7 suffers from limited rate capability due to low Li+ ion diffusivity and poor electronic conductivity. To overcome these limitations, in this study, we designed a new synthesis route to prepare monodisperse mesoporous TiNb2O7 microspheres. Delicate control over annealing temperature offers a way to manipulate the grain size and specific surface area of TiNb2O7 microspheres. Our investigation revealed there was a compromise between these structural parameters the LIB performance of TiNb2O7 microspheres. High surface area is obtained at the expense of grain size, and hence electrical conductivity and ion diffusivity are influenced by these two factors in different manners, giving rise to an optimal condition for the best compromise. This highlights the importance of gaining a comprehensive understanding of the critical factors governing the electrochemical behavior of TiNb2O7 to establish a design principle for advanced electrode materials. |
