High Capacity Prussian Blue Analogue@Reduced Graphene Oxide/Li4Ti5O12 Composite as an Anode Material for Lithium- Ion Batteries with a Broad Voltage Window

A narrow electrochemical window, poor electronic conductivity and lithium ions transfer capability slow down the mass application of Li4Ti5O12 (LTO) as power batteries in passenger cars with a long range. An effective way to improve the capacity and energy density of LTO is to include it in a composite materials to provide a good ionic and electronic conductive network followed by excess discharge to about 0 V vs. Li+/Li. Mn-Fe based Prussian blue analogue (Mn-PBA) nanoparticles with special open framework structure anchor on the reduced graphene oxide (rGO) conferred a high electronic and ionic conductivity and similar charge/discharge voltage plateaus with LTO. As a result, the Mn- PBA@rGO/LTO composite takes full advantages of high capacity Mn-PBA and the high electronic conductivity rGO sheets. It delivered a high reversible capacity (301.7 mAh g-1 at 0.2 C) and superior rate performance (208.5 mAh g-1 at 30 C) in a broad electrochemical voltage range between 0.01 and 3 V in half cells. Furthermore, a capacity of 232.6 mAh g-1 at 1 C of Mn-PBA@rGO/LTO-10% was measured and good cycling performance was obtained in pouch cells with LiNi0.6Co0.2Mn0.2O2 (NCM622) as a cathode and Mn-PBA@rGO/LTO-10% as anode, indicating that the Mn- PBA@rGO/LTO-10% composite is a promising anode material for lithium-ion batteries (LIBs).