Toward rational design of N-doped Li4Ti5O12@carbon anode materials for high-performance lithium-ion batteries

The construction of efficient nitrogen doping and carbon coating Li4Ti5O12 anode materials is of critical importance for high-performance lithium-ion batteries. Herein, nitrogen-doped Li4Ti5O12@carbon nanoparticles have been synthesized via a one-step straight-forward strategy under solid-state conditions using chitosan as novel nitrogen/carbon source. The process with introducing chitosan incorporates that nitrogen-doped into both Li4Ti5O12 lattice and carbon could enlarge both the lattice volume of Li4Ti5O12 and the content of disordered carbon, which give rise to shortened path of Li+ ions intercalation and enhanced bulk Li4Ti5O12 electronic conductivity. Meanwhile, the introduction of chitosan could inhibit the agglomeration of nanoparticles and amplify the specific surface area so as to transfer Li+ ions faster, especially at high current density. As a result, the reversible discharge capacity of nitrogen-doped Li4Ti5O12@carbon electrode is up to 121.8 mAh g−1 and still remains at 117.1 mAh g−1 after 500 cycles at a current density of 10 C. Therefore, nitrogen-doped Li4Ti5O12@carbon nanoparticles electrode could be a potential candidate as an anode material for lithium-ion batteries.