Solid State Ionics, Vol.303, 89-96, 2017
Controlling Li2CuO2 single phase transition to preserve cathode capacity and cyclability in Li-ion batteries
Li2CuO2 is synthesized via a solid-state reaction and its structure and microstructure is characterized using X-Ray Diffraction, Scanning Electron Microscopy and N2 adsorption-desorption isotherms. The capacity of cathode material is evaluated at different preparation conditions to determine the factors affecting charge retention, cyclability, and assuring reproducibility during electrode fabrication. Progressing from previous reports, a maximum capacity retention of 140 mAh g(-1) is attained in the potential window from 1.5 to 42 V (Li/Li-0) during ten cycles at C/15. The low capacity retention at extended cyding has been associated to the participation of irreversible oxygen redox process evaluated by theoretical calculations and cyclic voltammetry. These processes are minimized when the cyding potential window is confined from 2.0 to 3.8 V (Li/Li-0), thus, achieving a higher capacity retention up to 100 mAh g(-1) during 60 cycles. Cycling at higher C/rates lowers the capacity down (60 mAh g(-1) at C/5), but the maximum capacity is restored when returning to C/15. Thus, making Li2CuO2 an attractive material either as active compound or additive in cathodes for Li-ion batteries, as a result of its intrinsic properties such as environmental benign, abundance, cost and straightforward preparation process. (C) 2017 Elsevier B.V. All rights reserved.