New Iron-Based Mixed-Polyanion Cathodes for Lithium and Sodium Rechargeable Batteries: Combined First Principles Calculations and Experimental Study

详细信息    查看全文

• 作者：Hyungsub Kim ; Inchul Park ; Dong-Hwa Seo ; Seongsu Lee ; Sung-Wook Kim ; Woo Jun Kwon ; Young-Uk Park ; Chul Sung Kim ; Seokwoo Jeon ; Kisuk Kang
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：June 27, 2012
• 年：2012
• 卷：134
• 期：25
• 页码：10369-10372
• 全文大小：278K
• 年卷期：v.134,no.25(June 27, 2012)
• ISSN：1520-5126

文摘

New iron-based mixed-polyanion compounds Li_xNa_4鈥?i>xFe₃(PO₄)₂(P₂O₇) (x = 0鈥?) were synthesized, and their crystal structures were determined. The new compounds contained three-dimensional (3D)sodium/lithium paths supported by P₂O₇ pillars in the crystal. First principles calculations identified the complex 3D paths with their activation barriers and revealed them as fast ionic conductors. The reversible electrode operation was found in both Li and Na cells with capacities of one-electron reaction per Fe atom, 140 and 129 mAh g^鈥?, respectively. The redox potential of each phase was 3.4 V (vs Li) for the Li-ion cell and 3.2 V (vs Na) for the Na-ion cell. The properties of high power, small volume change, and high thermal stability were also recognized, presenting this new compound as a potential competitor to other iron-based electrodes such as Li₂FeP₂O₇, Li₂FePO₄F, and LiFePO₄.