Insights into temperature-induced evolution of spinel MnCo2O4 as anode material for Li-ion batteries with enhanced electrochemical performance

The mechanism of non-stoichiometric MnCo2O4+delta to stoichiometric MnCo2O4 structural transformation in the calcination temperature range of 350-650 degrees C and its morphology evolution from nanoplates with {112} facets to quasi nanoplates with {110} facets in the preferential orientation of [220] direction is investigated in detail and confirmed using XPS, HRTEM, TGA, and XRD analysis. By having a profound understanding of this mechanism, MnCo2O4 with a well-controlled structure and morphology was synthesized via co-pre-cipitation as the anode for Li-ion batteries to overcome the capacity fading issue. Moreover, the anode microstructure was optimized based on the correlation between Li+ storage, electrode durability, and in-terfacial resistance through the electrochemical response of electrode components, including MnCo2O4, carbon black, and binder. The optimum electrode exhibited a high initial discharge capacity of 2063 mAh g-1 at 400 mA g-1, excellent rate capability (807 mAh g-1 at 1000 mA g-1), and outstanding cycling performance (709 mAh g-1 at 400 mA g-1 after 150 cycles). These are attributed to the balance between the high surface area and robust architecture of MnCo2O4, and the stability, conductivity, and porosity of the electrode.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

The mechanism of non-stoichiometric MnCo2O4+delta to stoichiometric MnCo2O4 structural transformation in the calcination temperature range of 350-650 degrees C and its morphology evolution from nanoplates with {112} facets to quasi nanoplates with {110} facets in the preferential orientation of [220] direction is investigated. By understanding this mechanism, MnCo2O4 with controlled structure and morphology was synthesized as the anode for Li-ion batteries to overcome capacity fading issue. The optimized electrode exhibited high initial discharge capacity, excellent rate capability, and outstanding cycling performance.