Enhancing Cyclic Performance and Rate Capability of Li4Ti5O12 for Lithium-Ion Batteries through Thin Carbon Coating

Lithium titanate (Li4Ti5O12, LTO), as a zero-strain material upon lithiation, typically possesses good cyclic performance, presenting an opportunity for use in lithium-ion batteries for electric vehicles. For practical applications, the electrical conductivity of the LTO should be improved while addressing its gassing issue. Here, a C-coated LTO (LTO@C) electrode material was synthesized by chemical vapor deposition, and a coating of C approximately 2 nm-thick was placed onto the LTO surface by decomposing acetylene at 700 degrees C for 15 min. Compared with the pristine LTO, the LTO@C did not exhibit significant changes in structure and morphology; however, it presented much better cyclic performance than the pristine LTO, i.e., the capacity retention improved from 41.3% to 77.6% within 500 cycles at room temperature and from 58.0% to 97.0% within 100 cycles at 55 degrees C.