Carbon Free High Loading Silicon Anodes Enabled by Sulfide Solid Electrolytes for Robust All Solid-State Batteries

TL;DR

This paper demonstrates that sulfide solid electrolytes enable stable, high-loading silicon anodes in all-solid-state lithium-ion batteries, overcoming interfacial stability issues and achieving high performance across various conditions.

Contribution

It introduces a novel approach using sulfide electrolytes to stabilize silicon anodes, enabling high-loading, durable all-solid-state batteries with excellent interfacial properties.

Findings

Stable operation of 99.9 wt% micro-Si anodes achieved.

High current density operation at room temperature.

Wide temperature range and high loadings demonstrated.

Abstract

The development of silicon anodes to replace conventional graphite in efforts to increase energy densities of lithium-ion batteries has been largely impeded by poor interfacial stability against liquid electrolytes. Here, stable operation of 99.9 weight% micro-Si (uSi) anode is enabled by utilizing the interface passivating properties of sulfide based solid-electrolytes. Bulk to surface characterization, as well as quantification of interfacial components showed that such an approach eliminates continuous interfacial growth and irreversible lithium losses. In uSi || layered-oxide full cells, high current densities at room temperature (5 mA cm 2), wide operating temperature (-20{\deg}C to 80{\deg}C) and high loadings (>11 mAh cm-2) were demonstrated for both charge and discharge operations. The promising battery performance can be attributed to both the desirable interfacial property between uSi and sulfide electrolytes, as well as the unique chemo-mechanical behavior of the Li-Si alloys.