A facile and low-cost Al₂O₃ coating as an artificial solid electrolyte interphase layer on graphite/silicon composites for lithium-ion batteries

Abstract

Graphite/silicon (G/Si) composites are considered as possible alternative anode materials to commercial graphite anodes. However, the unstable solid electrolyte interphase (SEI) on G/Si particles results in rapid capacity decay, impeding practical applications. Herein, a facile and low-cost Al2O3 coating was developed to fabricate stable artificial SEI layers on G/Si composites. The amorphous Al2O3 coating with a thickness of 10–15 nm was synthesized by a simple sol–gel method followed by high-temperature annealing. The Al2O3 coated G/Si anode delivers an initial discharge capacity of 540 mAh g−1 at 25 °C and has improved Coulombic efficiency and cycling stability. After 100 cycles, the capacity retention is 76.4%, much higher than the 56.4% of the uncoated anode. Furthermore, the Al2O3 coating was found to be more effective at improving the stability of G/Si at a higher temperature (55 °C). This was explained by the Al2O3 coating suppressing the growth of SEI on Si/G and thus reducing the charge transfer resistance at the G/Si–electrolyte interface. It is expected that the Al2O3 coating prepared by the sol–gel process can be applied to other Si-based anodes in the manufacture of practical high-performance lithium-ion batteries.

Size Effect in SnO2/Al2O3 Core/Shell Nanowires after Battery Cycling

“…[12,17,18,21] For maintaining the inactive behavior of the buffer layer, it should not repeatedly store and release lithium, but might also function as an artificial SEI layer. [22,23] Hence, it has to be ion conductive, while electron blocking is beneficial. [24] Mechanically, it should conserve the underlying structure during cycling.…”

Review on Action Mechanism and Characterization of Natural/Artificial Solid Electrolyte Interphase of Lithium Battery: Latest Progress and Future Directions

“…Intercalation compounds mainly undergo insertion and conversion reactions in lithium-ion batteries. The SEI film is an important property that determines the results of the reaction and the electrochemical performance of the batteries. − The thickness of the SEI film directly affects the speed at which Li + passes through the lithium-ion battery during insertion or extraction, thereby indirectly affecting many electrochemical properties of lithium ions. After replacing the positive and negative electrodes of lithium-ion batteries with intercalation compounds, the impact on the SEI film is very significant.…”

Porous Carbon with Alumina Coating Nanolayer Derived from Biomass and the Enhanced Electrochemical Performance as Stable Anode Materials

“…As a result, capacity decay is greatly reduced [ 42 ]. A facile and cost-effective G/Si composite with Al 2 O 3 coatings was proposed by Zhu et al [ 43 ]. Furthermore, the amorphous Al 2 O 3 coating (thickness: 10–15 nm) enhances the electrochemical performance of the material and provides a stable artificial SEI layer.…”