High Capacity Positive Electrode Material for Room Temperature Na Ion Battery: NaxMn2/3Co1/6Ni1/6O2
High Capacity Positive Electrode Material for Room Temperature Na Ion Battery: NaxMn2/3Co1/6Ni1/6O2
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DOI：
10.1149/2.0181504jes
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发表时间：
2015
影响因子：
3.9
通讯作者：
R. Kataoka;T. Mukai;A. Yoshizawa;K. Inoue;T. Kiyobayashi;T. Sakai
中科院分区：
文献类型：
--
作者：
R. Kataoka;T. Mukai;A. Yoshizawa;K. Inoue;T. Kiyobayashi;T. Sakai
A layered compound, Na x Mn 2/3 Co 1/6 Ni 1/6 O 2 (NMCN), prepared by a solid-state reaction, served as a high capacity positive electrode material with the reversible capacity of ca. 200 mA· h· g− 1 using a Na foil as the counter electrode. A high-resolution synchrotron X-ray diffraction (XRD) analysis revealed that, whereas the NMCN sample had the P3 structure (R3m) when the precursor was heated below 700 C, the P2 structure (P6 3/mmc) was obtained when heated above 800 C. The latter excels over the former in both capacity and cycle stability; ie, the initial discharge capacities and potentials of the P2 and P3-NMCN were 216 mA· h· g− 1, 2.87 V vs. Na+/Na and 206 mA· h· g− 1, 2.78 V vs. Na+/Na, respectively. The P2-MNCN retained 80% of its initial discharge capacity while the P3-NMCN dropped to 69% after 30 cycles in the potential range of 1.0–4.5 V vs. Na+/Na. An in-situ XRD analysis revealed that the lattice volume of the P2-NMCN contracts and expands by 20% during the charge and discharge (ie, Na extraction and insertion) without drastically changing its crystallographic structure.
