Effect of Precursor Solution Temperature on the Morphology and Electrochemical Performance of Electrodeposited MnO 2 Nanofilms for Lithium-Ion Batteries

Abstract

Abstract This study investigated the impact of precursor solution temperature on the electrodeposition of MnO 2 material, which were prepared on a nickel substrate using the electrodeposition method under varying precursor solution temperatures of 25℃, 40℃, 50℃, and 60℃, respectively. The morphology and structure of the MnO 2 nanomaterials were characterized using SEM and TEM. These materials were subsequently employed as anodes in Lithium-Ion Batteries to study their electrochemical performance. The results indicate that an increase in temperature induces preferential aggregation and growth of MnO 2 nanosheets towards specific orientations, which is advantageous for enhancing the electrochemical performance of MnO 2 electrode materials. Notably, the electrode material prepared at a solution temperature of 50℃ exhibited optimal performance. At 50℃, the initial discharge specific capacity reached a remarkable 1476.7 mAh g-1 , and the rate capability even exceeded twice that at 25℃. Additionally, the charge transfer impedance was lower, which could be attributed to the growth of the highly conductive β-MnO 2 main phase under 50℃. However, excessively high temperatures impede this growth process, leading to a reduction in electrochemical performance. This study presents a novel approach for effectively improving electrodeposited nanomaterials, offering insights into the optimization of electrochemical performance.