TY - JOUR
T1 - Effects of Grain Boundaries and Surfaces on Electronic and Mechanical Properties of Solid Electrolytes
AU - Xie, Weihang
AU - Deng, Zeyu
AU - Liu, Zhengyu
AU - Famprikis, Theodosios
AU - Butler, Keith T.
AU - Canepa, Pieremanuele
PY - 2024
Y1 - 2024
N2 - Extended defects, including exposed surfaces and grain boundaries (GBs), are critical to the properties of polycrystalline solid electrolytes in all-solid-state batteries (ASSBs). These defects can alter the mechanical and electronic properties of solid electrolytes, with direct manifestations in the performance of ASSBs. Here, by building a library of 590 surfaces and grain boundaries of 11 relevant solid electrolytes—including halides, oxides, and sulfides— their electronic, mechanical, and thermodynamic characteristics are linked to the functional properties of polycrystalline solid electrolytes. It is found that the energy required to mechanically “separate” grain boundaries can be significantly lower than in the bulk region of materials, which can trigger preferential cracking of solid electrolyte particles in the grain boundary regions. The brittleness of ceramic solid electrolytes, inferred from the predicted low fracture toughness at the grain boundaries, contributes to their cracking under local pressure imparted by lithium (sodium) penetration in the grain boundaries. Extended defects of solid electrolytes introduce new electronic interfacial states within bandgaps of solid electrolytes. These states alter and possibly increase locally the availability of free electrons and holes in solid electrolytes. Factoring effects arising from extended defects appear crucial to explain electrochemical and mechanical observations in ASSBs.
AB - Extended defects, including exposed surfaces and grain boundaries (GBs), are critical to the properties of polycrystalline solid electrolytes in all-solid-state batteries (ASSBs). These defects can alter the mechanical and electronic properties of solid electrolytes, with direct manifestations in the performance of ASSBs. Here, by building a library of 590 surfaces and grain boundaries of 11 relevant solid electrolytes—including halides, oxides, and sulfides— their electronic, mechanical, and thermodynamic characteristics are linked to the functional properties of polycrystalline solid electrolytes. It is found that the energy required to mechanically “separate” grain boundaries can be significantly lower than in the bulk region of materials, which can trigger preferential cracking of solid electrolyte particles in the grain boundary regions. The brittleness of ceramic solid electrolytes, inferred from the predicted low fracture toughness at the grain boundaries, contributes to their cracking under local pressure imparted by lithium (sodium) penetration in the grain boundaries. Extended defects of solid electrolytes introduce new electronic interfacial states within bandgaps of solid electrolytes. These states alter and possibly increase locally the availability of free electrons and holes in solid electrolytes. Factoring effects arising from extended defects appear crucial to explain electrochemical and mechanical observations in ASSBs.
KW - electronic properties
KW - first-principles calculations
KW - grain boundaries
KW - mechanical properties
KW - solid electrolytes
KW - surfaces
UR - http://www.scopus.com/inward/record.url?scp=85182480806&partnerID=8YFLogxK
U2 - 10.1002/aenm.202304230
DO - 10.1002/aenm.202304230
M3 - Article
AN - SCOPUS:85182480806
SN - 1614-6832
VL - 14
JO - Advanced Energy Materials
JF - Advanced Energy Materials
IS - 17
M1 - 2304230
ER -