Synthesis and characterization of mesoporous titanium pyrophosphate as lithium intercalation electrode materials

Abstract

Mesoporous titanium pyrophosphates have been synthesized by a sol–gel template method with further calcinations at or below the temperature of 700 °C. When calcined at 800 °C, crystalline TiP 2O 7 will be formed accompanied with the break down of meso-structure in the precursor. Mesoporous TiP 2O 7 shows a similar lithium ion intercalation behavior to that of solid solution in the electrochemical tests. When cycled at high charge/discharge rate, mesoporous TiP 2O 7 calcined at 700 °C delivers a higher specific discharge capacity than that of crystalline TiP 2O 7, indicating that mesoporous structure is beneficial for improving the transportation and intercalation/deintercalation behavior of lithium ions in the materials, thus improving the charge/discharge performance of the materials at high charge/discharge rate.