Composite number

Engineering

Lithium (medication)

Metallurgy

Materials science

Endocrinology

Silicon

Carbon fibers

Chemical engineering

Physical chemistry

Nanotechnology

Alloy

Composite material

Medicine

Chemistry

Electrode

Anode

Sulfide

Electrolyte

Fast ion conductor

Science

The development of silicon anodes for lithium-ion batteries has been largely impeded by poor interfacial stability against liquid electrolytes. Here, we enabled the stable operation of a 99.9 weight % microsilicon anode by using the interface passivating properties of sulfide solid electrolytes. Bulk and surface characterization, and quantification of interfacial components, showed that such an approach eliminates continuous interfacial growth and irreversible lithium losses. Microsilicon full cells were assembled and found to achieve high areal current density, wide operating temperature range, and high areal loadings for the different cells. The promising performance can be attributed to both the desirable interfacial property between microsilicon and sulfide electrolytes and the distinctive chemomechanical behavior of the lithium-silicon alloy.

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