We carried out redox-couple and counter-cation exchange in NASICON-type M_2(XO_4)_3 (M: Fe and Al; X: S, Mo and W) to control the cathode performance. The Fe^<3+>/Fe^<2+> redox potential in NASICON matrix is changed by the local crystalline field at the iron resulting from polarization of oxygen towards the counter cation in the polyanionic complex. It is confirmed by ^<57>Fe Mossbauer resonance, Fe-2p XPS, Mo K-XAFS and electrochemical measurements. This inductive effect in NASICON matrix is a significant material control technique for cathode design. We also found a promising anode candidate by ion exchange of Fe by Al in Fe_2(MoO_4)_3. The reversible capacity of Al_2(MoO_4)_3 reached almost 200mAh/g between 3.5V and 1.2V.
|寄稿の翻訳タイトル||Inductive Effect in NASICON-Type Cathodes for Lithium Secondary Batteries|
|ジャーナル||The Reports of Institute of Advanced Material Study,Kyushu University|
|出版ステータス||出版済み - 12 1999|