A Facile Surface Reconstruction Mechanism toward Better Electrochemical Performance of Li(4)Ti(5)O(12) in Lithium‐Ion Battery

Through a facile sodium sulfide (Na(2)S)‐assisted hydrothermal treatment, clean and nondefective surfaces are constructed on micrometer‐sized Li(4)Ti(5)O(12) particles. The remarkable improvement of surface quality shows a higher first cycle Coulombic efficiency (≈95%), a significantly enhanced cycling performance, and a better rate capability in electrochemical measurements. A combined study of Raman spectroscopy and inductive coupled plasma emission spectroscopy reveals that the evolution of Li(4)Ti(5)O(12) surface in a water‐based hydrothermal environment is a hydrolysis–recrystallization process, which can introduce a new phase of anatase‐TiO(2). While, with a small amount of Na(2)S (0.004 mol L(−1) at least), the spinel‐Li(4)Ti(5)O(12) phase is maintained without a second phase. During this process, the alkaline environment created by Na(2)S and the surface adsorption of the sulfur‐containing group (HS(−) or S(2−)) can suppress the recrystallization of anatase‐TiO(2) and renew the particle surfaces. This finding gives a better understanding of the surface–property relationship on Li(4)Ti(5)O(12) and guidance on preparation and modification of electrode material other than coating or doping.