The effect of diethylenetriamine on the solvothermal reactions of polyethyleneimine-graphene oxide/lithium titanate nanocomposites for lithium battery anode

A simple preparation of N-doped graphene/Li4Ti5O12-TiN (NG/LTO-TiN) from the polyethyleneimine-graphene oxide/Li4Ti5O12 (PEI-GO/LTO) is achieved through a solvothermal reaction in the presence of diethylenetriamine (DETA). The solvothermal reaction converts PEI-GO/LTO into corresponding NG/LTO-TiO2, which could be simultaneously converted into NG/LTO-TiN via reacting with DETA as an N source. It is proposed that the electrically conductive titanium nitride (TiN) is formed at the interface between the surfaces of Li4Ti5O12 (LTO) and nitrogen doped graphene (NG). When used as an anode material for lithium ion battery (LIB), the NG/LTO-TiN exhibited superior rate capability in comparison to LTO, reduced GO/Li4Ti5O12-TiO2 (RGO/LTO-TiO2) and NG/LTO-TiO2 nanocomposites, with excellent cyclic stability up to 100 cycles. Moreover, the ionic diffusion coefficient is 3.6 × 10−12 cm2 s−1 for NG/LTO-TiN-94.3%, which is a higher value than that of the LTO (8.85 × 10−13 cm2 s−1), RGO/LTO-TiO2-93.5% (1.48 × 10−12 cm2 s−1), and NG/LTO-TiO2-94.2% (2.51 × 10−12 cm2 s−1) nanocomposites studied.