- 作者: 劉如熹
- 作者服務機構: Department of Chemistry, National Taiwan University, Taipei 106, Taiwan, R.O.C.
- 中文摘要: The local structure and electronic states of Co3+ substituted lithium manganate spinels of the composition Li(Mn2-xCox)O4 (0 £ x £ 0.4) have been probed by X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies at the Mn and Co edges. The substitution of Co3+ into the Mn sites causes an oxidation of Mn3+ to Mn4+, decreasing the localized Jahn-Teller distortion of the lattice. This in turn leads to a shortening of the Mn-O(M) bond length and a reduction in local structural disorder of the Mn(Co)O6 octahedra. The data show that the replacement of d4 Mn3+ by d6 Co3+ in the octahedral sites of the spinel structure eliminates the local disorder in the lattice around the Mn3+O6 octahedra which are distorted by Jahn-Teller stabilization of the electronic state.
- 英文摘要: --
- 中文關鍵字: X-ray absorption near-edge structure (XANES); Extended X-ray absorption fine structure (EXAFS); Li(Mn2-xCox)O4; Lithium-ion based secondary battery.
- 英文關鍵字: X-ray absorption near-edge structure (XANES); Extended X-ray absorption fine structure (EXAFS); Li(Mn2-xCox)O4; Lithium-ion based secondary battery.