Carbon-coated TiP2O7 with improved cyclability in aqueous electrolytes

In this paper, porous and highly crystalline carbon-coated TiP2O7 has been prepared by a sucrose assisted all-in-one sintering method at a much lower temperature (700 °C) rather than the traditional solid-state reaction synthesis (1000 °C). The prepared TiP2O7 is coated by a nanometer-thick carbon film with improved conductivity and stability in water. The electrochemical performances of this material are found greatly enhanced. The carbon-coated TiP2O7/LiMn2O4 system in 1 mol L −1 Li2SO4 aqueous electrolyte delivers discharge capacities of 86 mAh g −1 and 40 mAh g −1 at the rates of 0.25 and 10 °C, respectively. Furthermore, it also exhibits an excellent cycling stability with capacity retention of 85% over 100 cycles, which is much better than the bared TiP2O7.