In-situ carbon coating to enhance the rate capability of the Li4Ti5O12 anode material and suppress the electrolyte reduction decomposition on the electrode

The in-situ carbon coated LTO composite (LTO/C-PR) is synthesized via a wet chemical method from the phenolic resin coated TiO2 (TiO2/PR) and Li2CO3. The results indicate that the coated carbon layer pyrolyzing from phenolic resin exhibits higher degree of graphitization than that of pyrolyzing from glucose. The LTO/C-PR composite shows better rate capability and cyclic performance than the LTO/C-G composite using glucose as pyrolytic carbon source. Furthermore, it is found that the higher graphitization of carbon layer can more efficiently suppress the interfacial reactions between the LTO and the electrolyte at the cut-off voltages of 1-3 V. Moreover, the higher graphitization of carbon layer is also favorable to impede the deeper reduction decomposition of the electrolyte below 1.0 V by forming a more successive and thinner SEI film on the LTO electrode. These results indicate that coating the LTO with higher graphitization of carbon layer should be more preferable to solve both the rate capability and the gas generation behavior of the LTO anode material.