Microstructural investigation of LixNi1/3Mn1/3Co1/3O2 (x ≤ 1) and its aged products via magnetic and diffraction study

• Published in: Journal of power sources Vol. 220; pp. 405 - 412
• Main Authors: Mohanty, D., Gabrisch, H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-12-2012; Elsevier
• Subjects: ANNEALING; Applied sciences; DIFFRACTION; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; ELECTRON DIFFRACTION; Exact sciences and technology; GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; Magnetic ordering; MORPHOLOGY; OXIDATION; OXIDES; REMOVAL; Spinel; SPINELS; STABILITY; Thermal ageing; THERMAL DEGRADATION; TRANSITION ELEMENTS; VALENCE; Spinel; Magnetic ordering; Electron diffraction; Thermal ageing; Heat treatment; Disordered system; Transition metal; Thermal stability; Magnetic measurement; Lithium battery; Transmission electron microscopy; Spinels; Imaging; Morphology; Ordering; Oxidation; Thermal annealing; Thermal degradation
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.08.005

The thermal stability of the layered oxide LiNi1/3Mn1/3Co1/3O2 and its delithiated product is studied by a combination of X-ray and electron diffraction, TEM imaging and magnetic measurements. Diffraction shows that a small fraction of the layered material converts to spinel phase following delithiation. More spinel phase is observed after thermal annealing. The morphology of the particle changes upon thermal annealing of delithiated materials. The selected area electron diffraction and the magnetic measurement results confirm the presence of Ni+2/Li+ disorder in the delithiated material, which increases upon thermal ageing. The oxidation states of the transition metal ions were determined from magnetic data. It is shown that the charge balance due to removal of Li+ is maintained through oxidation of Ni+2 and that the oxidation states remain stable during subsequent annealing. No antiferromagnetic ordering or crystallographic in plane ordering of transition metal ions is observed. These results clearly describe the thermal degradation of LixNi1/3Mn1/3Co1/3O2 (x ≤ 1) occur through the significant microstructural changes.
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▸ The cation-ordering of LixNi1/3Mn1/3Co1/3O2 before and after ageing were studied. ▸ Magnetic response and selected area electron diffraction techniques were correlated. ▸ Maximum extent of cation ordering in aged LixNi1/3Mn1/3Co1/3O2 was observed. ▸ No change in oxidation states of metal ions were observed in aged LixNi1/3Mn1/3Co1/3O2. ▸ Change in particle morphology was observed in aged LixNi1/3Mn1/3Co1/3O2.