Chronicle evolution of research on TIO ₂ based lithium-ion battery anodes

In the past few decades, Titanium dioxide (TiO ₂ ) has attracted considerable attention as a promising alternative lithium-ion battery anode. It is featured with excellent electrochemical stability, high operating voltage and limited volume change upon lithiation/delithiation. However, the low electronic conductivity, low Li ion diffusion coefficient and low initial coulomb efficiency limit the further application. Extensive research has been performed to solve these critical issues. Major strategies including size tuning, surface coating, and atomic doping have been developed to solve these critical problems. It is well recognized that the particle size is one of the most important factors determining the performance of the TiO ₂ based lithium-ion battery anodes. The size reduction significantly improves electrochemical kinetics, but it also introduces additional critical problems. Therefore, it is essential to integrate size tuning with other strategies to achieve optimized practically relevant performance. Quite a few review articles have been published to summarize the research activities over the last few decades. However, to our best knowledge, it has never been addressed with a chronicle perspective, where the evolution of the studies in the past time is comprehensively addressed. Here we propose to write a chapter on the synthesis and application of the TiO ₂ based lithium-ion battery anodes. The evolution of the studies on the synthetic methods, performance improvement, and fundamental mechanism of the size tuning strategy along with time over the last few decades will be thoroughly addressed. In this chapter, the authors would like to firstly give a systematic background introduction of the TiO ₂ based lithium-ion battery anode, followed by the critical issues related to the application of the TiO ₂ . Thereafter, methods to solve the problems will be summarized briefly. Then the studies based on the size tuning strategies in different periods of time will be addressed and commented. Finally, conclusion and outlook will be made. By reading this chapter, the readers will gain unique comprehensive knowledge and deep insights about the evolution of the size tuning studies of the TiO ₂ based lithium-ion battery anodes.