Investigation of Li5Cr7Ti6O25 as novel anode material for high-power lithium-ion batteries

In this work, Li5Cr7Ti6O25 as a new anode material for rechargeable batteries is fabricated through a simple sol-gel method at different calcination temperatures. The X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, charge/discharge curve and cyclic voltammograms are utilized to study the crystal structures, morphologies and electrochemical properties of as-obtained Li5Cr7Ti6O25 samples. The impact of calcination temperatures on morphologies and electrochemical properties of Li5Cr7Ti6O25 is discussed in detail. The test result shows that the 800 °C is a proper calcination temperature for Li5Cr7Ti6O25 with excellent electrochemical properties. Cycled at 200 mA g−1, it displays a high initial reversible capacity of 146.6 mA h g−1 and retains a considerable capacity of 130.8 mA h g−1 after 300 cycles. Even cycled at large current density of 500 mA g−1, the initial reversible capacity of 129.6 mA h g−1 with the capacity retention of 88% after 300 cycles is achieved, which is obviously higher than that of Li5Cr7Ti6O25 prepared at 700 °C (80.5 mA h g−1 and 68%) and 900 °C (98.4 mA h g−1 and 80%). In addition, in-situ XRD analysis reveals that Li5Cr7Ti6O25 exhibits a reversible structural change during lithiation and delithiation processes. The above prominent electrochemical performance indicates the great potential of the Li5Cr7Ti6O25 obtained at 800 °C as anode material for rechargeable batteries.