High-Rate SiO Lithium-Ion Battery Anode Enabled by Rationally Interfacial Hybrid Encapsulation Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Silicon (Si) anodes offer high theoretical capacity for lithium-ion batteries but suffer from low conductivity, sluggish interfacial charge transfer (ICT), and unstable interfaces.
• Interfacial engineering, particularly hybrid coatings, is crucial for regulating interfacial reactions and forming stable solid electrolyte interphases (SEI) to overcome Si anode limitations.

Purpose of the Study:

• To develop a hybrid MXene-graphene oxide (GO) coating for Si microparticles to enhance lithium-ion battery anode performance.
• To improve coupled electron/lithium-ion transport and interfacial stability for high-rate and long-cycle life applications.

Main Methods:

• Constructed a hybrid coating of Ti3C2Tx MXene and graphene oxide (GO) on Si microparticles.
• Utilized covalent bonding (Ti-O-Si, Ti-O-C) between Si, MXene, and GO to reduce ICT resistance.
• Investigated the synergistic effects of MXene and GO for pseudocapacitance-dominated lithium storage and analyzed interfacial chemistry.

Main Results:

• The Si@MXene@GO anode demonstrated superior rate capability (1175.9 mAh g-1 at 5 A g-1) and long cycling stability (1087.6 mAh g-1 after 1000 cycles at 2.0 A g-1).
• The hybrid coating facilitated enhanced electron and ion transport, leading to pseudocapacitance-dominated charge storage.
• An inorganically rich SEI layer with gradient LiF and Li2O distribution ensured mechanical stability during cycling.

Conclusions:

• The hybrid MXene-GO coating effectively addresses the limitations of Si anodes, significantly improving lithium-ion storage performance.
• This interfacial encapsulation strategy provides a viable pathway for developing advanced Si anodes for fast-charging lithium-ion batteries.