A high-magnification image of the fabricated electrodes.

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, which makes the batteries less flexible and have a low energy density.

Now, a Chinese research group has developed a simple and scalable process to fabricate LTO nanosheets with a N-doped carbon coating, which can be assembled into a film that can be used as a binder-free and flexible electrode for LIBs that does not require any current collectors. This flexible electrode shows an excellent rate capability and a significantly improved cycling performance.