Carbon-free high-loading silicon anodes enabled by sulfide solid electrolytes.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Silicon anodes offer high theoretical capacity for lithium-ion batteries but suffer from poor interfacial stability with liquid electrolytes.
• This instability leads to continuous interfacial growth and irreversible lithium losses, hindering practical application.

Purpose of the Study:

• To develop a stable microsilicon anode for lithium-ion batteries.
• To investigate the use of sulfide solid electrolytes for interface passivation.

Main Methods:

• Utilized sulfide solid electrolytes to passivate the interface of a 99.9% microsilicon anode.
• Performed bulk and surface characterization to analyze interfacial components.
• Assembled and tested microsilicon full cells under various conditions.

Main Results:

• The sulfide solid electrolyte effectively eliminated continuous interfacial growth and irreversible lithium losses.
• Microsilicon full cells demonstrated high areal current density, a wide operating temperature range, and high areal loadings.
• Characterization confirmed stable interfaces between microsilicon and sulfide electrolytes.

Conclusions:

• Sulfide solid electrolytes enable stable operation of high-loading microsilicon anodes in lithium-ion batteries.
• The stable interface and favorable chemomechanical properties of lithium-silicon alloys contribute to enhanced battery performance.