Crystal and electronic structure change determined by various method for delithiation process of Lix(Ni,Mn)O2-based cathode material

✍ Scribed by Oki Sekizawa; Takuya Hasegawa; Naoto Kitamura; Yasushi Idemoto

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 665 KB
• Volume: 196
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2011.01.018

✦ Synopsis

We investigated effects of delithiation on crystal, electronic structure, thermodynamic stability and physical property of Li x Ni 0.5 Mn 0.5 O 2 by using a chemical delithiation treatment with ammonium peroxodisulfate, and compared the results with those of electrochemical delithiation. X-ray diffraction and thermodynamic data indicated that there was no phase transition in the samples after the chemical delithiation treatment within the lithium range of 0.50 ≤ x ≤ 1.00. From the ICP measurements and potentiometric titration, it was found that the chemical treatment successfully remove Li from the structure without any elution of Ni and Mn, but it accompanied O 2 removal at an initial process of the delithiation, i.e. 0.80 ≤ x ≤ 1.00. Crystal and electronic structure analyses also suggested such a O 2 removal at the lithium content range in the chemical delithiation method, although the estimated structure changes below x = 0.80 showed similar tendencies to those by the electrochemical delithiation.