Tailored solution combustion method for enhancing high voltage electrochemical performance Li1.2Ni0.1Mn0.6Co0.1O2 as cathode material for lithium-ion batteries

Abstract

The Lithium and Manganese-rich layered oxides with the formula Li1.2Ni0.1Mn0.6Co0.1O2 (LMR-NMC) are considered the most promising cathode materials for next-generation lithium-ion batteries due to their high energy densities, low cost, high thermal stability, and environmental safety. This paper reports the synthesis of LMR-NMC oxides in the presence of glycine-urea or citric acid-urea as surface modifiers for LMR-NMC-A and LMR-NMC-B, respectively using the solution combustion technique. The crystal structures of LMR-NMC-A and LMR-NMC-B samples were confirmed to have Hexagonal α-NaFeO2 structures in the R-3m space group. The HRSEM images reveal two different morphologies of the samples; Nano platelet (LMR-NMC-A) and Cubic-like (LMR-NMC-B). The cyclic voltammetric studies (CV) performed at a low scan rate value of 0.1 mV s−1 and a potential window of 2.0–5.0 V confirm the formation of the irreversible Li2MnO3 phase above 4.8 V in the first cycle and the presence of three redox peaks corresponding to Ni2+/Ni4+, Co2+/Co3+, and Mn3+/Mn in the subsequent cycles. The electrochemical properties of LMR-NMC-A and LMR-NMC-B electrodes demonstrated an initial discharge-specific capacity of 325.21 mAh g−1 and 300 mAh g−1, respectively, in a potential range between 2.0 and 5.0 V at a 0.1C rate. A comparison of the electrochemical properties of both morphologies of LMR-NMC revealed that the Nanoplatelet-like (LMR-NMC-A) sample performs better than the cubic-like (LMR-NMC-B) sample. The Nanoplatelet-like layered oxide demonstrated a high specific capacity of 180 mAh g−1 at a 1C rate and a high Coulombic efficiency of 86% after 200 cycles. BET indicates that LMR-NMC-A has a significantly higher surface area and substantial pore volume than LMR-NMC-B, addressing high voltage working capability, low voltage fading, and high specific capacitance values to a greater extent. These findings confirm the suitability of LMR-NMC-A as a cathode material for lithium-ion batteries used in high-load appliances and heavy vehicles.