Interphases and Electrode Crosstalk Dictate the Thermal Stability of Solid-State Batteries

Abstract

Solid-state batteries, because of their high energy density, are promising candidates for long-range electric vehicles and electric aviation. While the enhanced safety potential of solid-state batteries has been typically ascribed to the nonflammability of solid electrolytes, an extensive interrogation of their thermal stability is still required. In this work, we reveal how the thermal stability in sulfide-based solid-state batteries is critically dependent on the interphase interactions at the solid electrolyte/Li interface, thereby illustrating the drastically different thermal signature of Li10SnP2S12 when compared with Li3PS4 and Li6PS5Cl. Our study shows that thermal runaway occurs even for a pristine Li10SnP2S12/Li interface and is severely exacerbated with cycling, which exhibits a massive thermal spike at the melting point of Li; this shift in thermal response uniquely correlates to the Li10SnP2S12 interphase evolution. On the basis of these distinct thermal signatures, cell-level mechanistic safety maps cognizant of the Li/interphase interaction, cathode/Li crosstalk, and specific energy are delineated.

Thermal Stability of Sulfide Solid Electrolyte with Lithium Metal

“…This result is consistent with reported research by Bairav S. Vishnugopi et al. [ 23 ] . In our experiment, L6‐Li shows the best thermal stability with the highest T 1 (302.3 °C) and T 2 (360 °C).…”

“…[ 31 ] Recently, thermal stability between sulfide SEs and Li metal has also been reported. [ 23 ] Limited by its instability in air, toxic gas release, and strong corrosiveness toward characterization instruments, investigation on thermal stability of sulfide SE is still very scarce compared to other electrolyte systems. Comprehensive in‐depth insights on thermal runaway mechanism of sulfide SE is urgently needed.…”

MXenes and Their Derivatives for Advanced Solid‐State Energy Storage Devices

“…[124] When external heating and internal short circuit occur, the high internal temperatures caused by the conversion from electrochemical energy to heat can lead to mixed combustion and decomposition. [125] Consequently, the thermal stability should be measured in advance for guiding the design of SSEs. DSC and TGA are the main methods to evaluate thermal stability.…”

Distinct thermal runaway mechanisms of sulfide-based all-solid-state batteries

“…Contrary to solid-solid reactions by direct contact, gas evolution and the subsequent gas-driven crosstalk reactions play a pivotal role in the thermal failure of batteries. 33,46,47 Hydrogen sulfide (H 2 S), generated from sulfide SEs upon exposure to moisture, 48 is poisonous, corrosive, and flammable, impeding the applications of sulfide-based ASSBs. In addition, sulfur dioxide (SO 2 ) was observed during the electrochemical cycles or heating process of sulfide-based ASSBs.…”

“…31 A growing number of automotive/battery manufacturers and start-ups have announced pilot schemes for ASSBs. Nevertheless, safety hazards still exist in sulfide-based ASSBs because of exothermic reactions between sulfide SEs and the Li 1− x CoO 2 cathode/Li anode 32,33 and harmful SO 2 released from sulfide-based composite cathodes under abusive conditions. 34 However, systematic mechanisms underlying these failure behaviors are lacking, hurdling the practical applications of ASSBs.…”