Effect of Potassium Doping on the Electrochemical Properties of 0.5Li2MnO3-0.5LiMn0.375Ni0.375Co0.25O2 Cathode. Issue 11 (1st January 2018)

• Record Type: Journal Article
• Authors: Dahiya, P. P.; Ghanty, C.; Sahoo, K.; Basu, S.; Majumder, S. B.
• Is Part Of: Journal of the Electrochemical Society. Volume 165:Issue 11(2018)
• Page Start: A2536
• Page End: A2548
• Publication Date: 2018-01-01
• Subjects: layered to spinel -- Li-rich cathode -- potassium doping; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0511811jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : In the realm of next generation cathode materials for Li-ion rechargeable batteries, Li and Mn riched (LMR) cathodes are important candidate because of its high nominal voltages and specific discharge capacities. However, capacity and voltage fade in LMR cathodes are attributed to the formation of spinel like phase with repeated cycling. In the present work, LMR cathode of composition 0.5Li2 MnO3 -0.5LiMn0.375 Ni0.375 Co0.25 O2 (layered notation Li1.2 Mn0.55 Ni0.15 Co0.1 O2 ) and its potassium doped variants are investigated in terms of their structural and electrochemical behavior. The cycleability, rate capability and voltage fade characteristics of potassium doped cathodes are found to be improved as compared to the undoped cathode. Thus, Li1.184 K0.016 Mn0.55 Ni0.15 Co0.1 O2 LMR cathode yields a capacity retention ∼86% after 50 charge-discharge cycles. Using X-ray diffraction and Raman spectroscopy analyses in conjunction with impedance spectroscopy, X-ray photoelectron spectroscopy, and galvanostatic intermittent titration technique we have established that cycling induced layered to spinel phase transition is retarded in K doped LMR cathodes to yield improved electrochemical performance and voltage fade characteristics.