Vibrational Entropy Contribution to Mixing Free Energy of Ni-Rich LiNi1-yCoyO2. Issue 6 (1st June 2022)

• Record Type: Journal Article
• Authors: Benedek, Roy
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 6(2022)
• Publication Date: 2022-06-01
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac71da
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : First principles density-functional-theory calculations are performed of the mixing free energy of the layered oxide LiNi1− y Co y O2, a model Li-ion-battery cathode material, at 1000 K. Analysis of internal energy, LN exchange, configurational entropy and vibrational entropy are combined to obtain the net mixing free energy. The vibrational entropy requires a more indirect treatment than the other terms; analysis based on heat capacity is presented to show that the vibrational entropy is of comparable magnitude to the configurational entropy, and it tends to promote solid-solution behavior in LiNi1− y Co y O2 .