前駆体処理温度によるTiO2(B)の安定性と電気化学特性への影響

概要

論文の詳細を見る
We have studied synthesis condition, mainly heating temperature of precursor and titanic acid, to improve electrochemical property of TiO2(B). TiO2(B) has been prepared from two kinds of Lepidocrocite type Rb0.75Ti1.75Li0.25O4 (Rb-700 or Rb-900) via titanic acid. The cleavage of precursor particles along (0k0) plane during proton exchange was observed for well crystallized precursor heated at 900°C (Rb-900). Chemical composition of titanic acids were expressed as TiO2·0.38H2O, however calculated chemical formula in TiO2·0.29H2O, under assumption of simple ion exchange of Rb+ and Li+ by H+. Titanic acid obtained from Rb-700 formed TiO2(B) in the wider temperature range from 350 to 550°C. TiO2(B) obtained from Rb-700 shows more sloped charge/discharge curve and 1.3 times higher discharge capacity than that from Rb-900. Discharge capacity depends on charge voltage and reaches 300 mAh g−1 at 0.9 V charge. This TiO2(B) also shows excellent rate performance and good coulombic efficiency after 3rd cycles.