A Self-Standing and Flexible Electrode of Li4Ti5O12 Nanosheets with a N-Doped Carbon Coating for High Rate Lithium Ion Batteries

Flexible energy-storage devices have attracted growing attention with the fast development of bendable electronic systems. Thus, the search for reliable electrodes with both high mechanical flexibility and excellent electron and lithium-ion conductivity has become an urgent task. Carbon-coated nanostructures of Li4Ti5O12 (LTO) have important applications in high-performance lithium ion batteries (LIBs). However, these materials still need to be mixed with a binder and carbon black and pressed onto metal substrates or, alternatively, by be deposited onto a conductive substrate before they are assembled into batteries, which makes the batteries less flexible and have a low energy density. Herein, a simple and scalable process to fabricate LTO nanosheets with a N-doped carbon coating is reported. This can be assembled into a film which can be used as a binder-free and flexible electrode for LIBs that does not require any current collectors. Such a flexible electrode has a long life. More significantly, it exhibits an excellent rate capability due to the thin carbon coating and porous nanosheet structures, which produces a highly conductive pathway for electrons and fast transport channels for lithium ions.