Layered Na[Ni1/3Fe1/3Mn1/3]O2 cathodes for Na-ion battery application

• Published in: Electrochemistry communications 2012, Vol.18, p.66-69
• Main Authors: Kim, Donghan, Lee, Eungje, Slater, Michael, Lu, Wenquan, Rood, Shawn, Johnson, Christopher S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Carbon; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Layered electrodes; Metal oxide; Na-ion; Sodium ion batteries
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2012.02.020

Na-ion batteries were tested with layered Na(Ni1/3Fe1/3Mn1/3)O2 cathodes and carbon anodes in a sodium-salt containing organic ester carbonate electrolyte. Layered single phase Na(Ni1/3Fe1/3Mn1/3)O2 was synthesized from solid-state reaction using a (Ni1/3Fe1/3Mn1/3)C2O4 oxalate precursor and Na2CO3 fired at 850°C with slow-cooling. The Na-ion NayC/Na1−y(Ni1/3Fe1/3Mn1/3)O2 cell had an average voltage of ~2.75V, modest capacity of 100mAhg−1 for 150cycles (1.5–4.0V), and a capacity of 94mAhg−1 at a 1°C rate. X-ray diffraction (XRD) data of extracted cycled electrodes were used to characterize material stability and phases formed upon cycling. It was found that Na1−y(Ni1/3Fe1/3Mn1/3)O2 (0≤y≤0.46) maintains a layered structure with good crystallinity over 150cycles. These results bode well for the development and optimization of rechargeable Na-ion batteries. [Display omitted] ► A Na-ion battery was cycled with Na[Ni1/3Fe1/3Mn1/3]O2 and carbon electrodes. ► Approximately y~0.46 Na reversibly intercalates in Na1–y[Ni1/3Fe1/3Mn1/3]O2. ► Over 150 cycles at a 0.5C rate with NayC/Na1–y[Ni1/3Fe1/3Mn1/3]O2 cell was shown. ► 1C rate (current density of 150 mA g–1) yielded a high capacity of 94 mA h g–1.