Interfacial synergy of pre-lithiation silicon anodes and GNP/MnO2/S cathodes for lithium polysulfides in silicon–sulfur batteries studied via DFT

Abstract

The development of innovative electrodes with outstanding high-rate cycling performance for the next generation of sulfur-based batteries has emerged as a key area of research. This study presents a straightforward approach for designing silicon/graphene nanoplates as an anode material using a one-step hydrothermal process. Additionally, to reduce the shuttle effect, the GNP/MnO₂/S cathode is investigated. In this study, MnO₂ particles are grown in situ on the surface of the GNP. The pre-lithiation Si/GNP anode and the MnO₂/GNP/S and GNP/S cathodes are evaluated at a current density of 1000 mA g⁻¹. The findings reveal an impressive capacity retention of 1048 mA h g⁻¹ after 200 cycles, indicating remarkable cycling performance for the cell with the pre-lithiation Si/GNP anode and the MnO₂/GNP/S cathode. The capacity retention observed in thicker electrodes highlights the synergistic effect of the effective chemical absorption of lithium polysulfides by MnO₂/GNP/S when used as sulfur hosts. Additionally, DFT calculations suggest that MnO₂ has a significant tendency to adhere to the surface of polysulfides, aligning well with our findings regarding cycle performance, rate performance, and discharge capacity. The novel electrode configuration introduced in this study provides a novel pathway for the large-scale production of high-performance pre-lithiation Si–S batteries.