Chromium-Modified Li4Ti5O12 with a Synergistic Effect of Bulk Doping, Surface Coating, and Size Reducing

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• 作者：Hailin Zou ; Xin Liang ; Xuyong Feng ; Hongfa Xiang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：August 24, 2016
• 年：2016
• 卷：8
• 期：33
• 页码：21407-21416
• 全文大小：739K
• 年卷期：0
• ISSN：1944-8252

文摘

Bulk doping, surface coating, and size reducing are three strategies for improving the electrochemical properties of Li₄Ti₅O₁₂ (LTO). In this work, chromium (Cr)-modified LTO with a synergistic effect of bulk doping, surface coating, and size reducing is synthesized by a facile sol–gel method. X-ray diffraction (XRD) and Raman analysis prove that Cr dopes into the LTO bulk lattice, which effectively inhibits the generation of TiO₂ impurities. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) verifies the surface coating of Li₂CrO₄ on the LTO surface, which decreases impedance of the LTO electrode. More importantly, the size of LTO particles can be significantly reduced from submicroscale to nanoscale as a result of the protection of the Li₂CrO₄ surface layer and the suppression from Cr atoms on the long-range order in the LTO lattice. As anode material, Li_4-xCr_3xTi_5–2xO₁₂ (x = 0.1) delivers a reversible capacity of 141 mAh g^–1 at 10 °C, and over 155 mAh g^–1 at 1 °C after 1000 cycles. Therefore, the Cr-modified Li₄Ti₅O₁₂ prepared via a sol–gel method has potential for applications in high-power, long-life lithium-ion batteries.