Electrochemical Characteristics of Solid State-Synthesized Mn2SiO4 as a Negative Electrode Material for Lithium-Ion Batteries

초록

Transition metal oxides that store lithium through a conversion reaction accommodate lithium ions and electrons during charge-discharge cycles, reducing the transition metal to its metallic state. Meanwhile, oxygen combines with lithium to form lithium oxide (Li2O). Although this mechanism offers a high theoretical capacity, it presents several challenges. Strong bonding between transition metals and oxygen induces voltage hysteresis during cycling, resulting in a high overpotential. Furthermore, substantial volume changes during cycling adversely affect long-term stability. To address these issues, this study explored the potential of Mn SiO , synthesized via a solidstate reaction method, as a negative electrode material for lithium-ion batteries. Mn SiO was prepared using MnCO and SiO as precursors and heat-treated at 1000 C under an argon atmosphere, yielding a high-purity material. We aim to evaluate and enhance the electrochemical performance of this material, particularly through its combination with carbon, to offer a novel and effective strategy for high-density energy storage. Notably, incorporating carbon into Mn SiO-based composites significantly improved performance, including electrical conductivity, and mitigated volume expansion, resulting in improved cycling stability and rate capability. The utility of carbon in this composite provides a novel direction for maximizing the potential of combined electrochemical storage systems. These findings indicate that Mn SiO4 has the potential to be used as a negative electrode material in high-capacity lithium-ion batteries and that carbon compositing is a promising strategy for enhancing the electrochemical properties of Mn SiO-based negative electrodes.

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