Synthesis and electrochemical properties of spinel Li(Li0.05Cu0.05Mn1.90)O4 by a flameless combustion method

• A (Li, Cu)-co-doped Li(Li0.05Cu0.05Mn1.90)O4 was synthesized by a flameless combustion method.
• The (Li, Cu)-co-doped Li(Li0.05Cu0.05Mn1.90)O4 has higher crystallinity.
• Low level of Li and Cu doping exhibits better rate capability and cycling performance.

A (Li, Cu)-co-doped cathode material Li(Li0.05Cu0.05Mn1.90)O4 was prepared by a flameless combustion synthesis at 500 °C for 3 h and then two-stage calcination at 700 °C for 6 h. Physical and electrochemical performances were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), galvanostatic charge–discharge cycling test, cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS) to investigate the influence of Li and Cu substitution on the lithium ion batteries. Li(Li0.05Cu0.05Mn1.90)O4 not only exhibited the initial discharge capacity of 106.9 mAh g−1 with a high retention of 89.2% after 500 cycles at 1.0 C but also retained 63.5% capacity after 1500 cycles at 5.0 C. Besides, a good rate capability at different current densities from 0.5 C to 5.0 C can be acquired. The (Li, Cu)-co-doped sample had excellent cycling stability in comparison with the LiMn2O4 cathode.