Carbon-coated nano-sized Li4Ti5O12 nanoporous micro-sphere as anode material for high-rate lithium-ion batteries

In this study, we report a facile process for preparing a carbon-coated nanosized Li4Ti5O12 nanoporous micro-sphere (CN-LTO-NMS) by a carbon pre-coating process combined with the spray drying method. The obtained material consists of a micron-size secondary sphere (10-20 mu m) accumulated by carbon-coated nanosized primary particles (similar to 200 nm). The nanosized primary particles and nano-thickness carbon layer uniformly coated over the particles as well as the interconnected nanopores greatly improve its rate capability. As a consequence, the resulting sample delivers a reversible capacity of 160 mAhg(-1) at 0.2 C, and shows remarkable rate capability by maintaining 79% of the capacity at 20 C (vs. 0.2 C), as well as excellent cycling stability with a capacity retention of 95% after 1000 cycles at 1 C rate (vs. 0.2 C).