Towards ultrafast lithium-ion batteries: A novel atomic layer deposition-seeded preparation of Li4Ti5O12-TiN-TiC anodes

Highlights: • Adding titanium and carbon powder as a mixed dopant. • Solid-phase sintering method to synthesize Li₄Ti₅O₁₂-TiN-TiC anodes under an N₂ atmosphere. • Dual-modification using TiN and TiC enhanced the electrochemical properties of Li₄Ti₅O₁₂ materials. TiN-TiC-modified Li₄Ti₅O₁₂ materials, known as LTO-TiN-TiC, were synthesized with spinel structures first through a simple one-step solid-phase sintering process in a nitrogen atmosphere with C and Ti as reducing agents. Transmission electron microscopy with X-ray photoelectron spectroscopy, Raman spectroscopy measurements, and energy-dispersive X-ray analysis confirmed that a TiN, TiC thin layer was successfully deposited onto the LTO surface. This work also researched the electrochemical performance of LTO-TiN-TiC nanomaterials, which showed better reversibility and higher rate capability than did pristine LTO. The discharge capacities of the LTO-TiN-TiC electrode were 78, 97, 110, 123, 147, 160 and 168 mAh g⁻¹ at charge/discharge rates of 20, 15, 5, 2, 1 and 0.5 C, respectively. The capacity retention was 82.19% and 93.65% after 200 cycles at 20 C and 5 C, with almost no capacity fading.