All-solid-state Li-ion battery: A study on the charge/discharge mechanism of an LMO-BCD-MgC system

Abstract

This study presents the fabrication of an all-solid-state lithium-ion battery using lithium manganese oxide (LiMn₂O₄; LMO) as the cathode, graphite (C), and carbon-coated magnesium (MgC) as the anode, along with a silicate-based solid electrolyte. To assess the charge/discharge mechanism, three polymeric membranes with varying weight percentages (5%, 30%, and 50%) of magnesium silicate are produced through battery-cloth deposition (BCD) for use as the solid electrolyte. The findings reveal that enhancing the magnesium silicate content in the solid electrolyte (particularly at 50%) results in an increased specific capacity of the battery. The MgC anode exhibits a peak capacity of approximately 780 mAh/g during the third cycle, maintaining capacity retention of 100% over 26 cycles, addressing the issues of low specific capacity and self-discharge in the solid-state Li-ion battery. Nevertheless, prolonged charge/discharge testing leads to an escalation in the surface roughness and porosity of the carbon coating on the MgC anode, resulting in a decline in capacity. These results demonstrate that the LMO-BCD-MgC battery system proposed in this study is a secure, eco-friendly, and cost-effective option with potential applications in energy storage.