TY - JOUR
T1 - The impact of lithium carbonate on tape cast LLZO battery separators
T2 - A balanced interplay between lithium loss and relithiation
AU - Touidjine, Kaouther
AU - Finsterbusch-Rosen, Melanie
AU - Kiyek, Vivien
AU - Ganapathy, Swapna
AU - Finsterbusch, Martin
AU - Guillon, Olivier
AU - Huijben, Mark
AU - Kelder, Erik
AU - Wagemaker, Marnix
AU - Fattakhova-Rohlfing, Dina
N1 - Publisher Copyright:
© 2024
PY - 2024/8
Y1 - 2024/8
N2 - Ceramic membranes made of garnet Li7Zr3La2O12 (LLZO) are promising separators for lithium metal batteries because they are chemically stable to lithium metal and can resist the growth of lithium dendrites. Free-standing garnet separators can be produced on a large scale using tape casting and sintering slurries containing LLZO powder, but the quality of the separators is severely compromized by the protonation of the moisture-sensitive LLZO during processing and the irreversible loss of lithium during sintering. In this work, an approach is presented to mitigate the degradation of the LLZO and produce high quality separators using Li2CO3 as a source of excess lithium. By systematically investigating the effects of Li2CO3 addition during the different steps of the tape casting process and the intricate relationship between the protonation and relithiation of LLZO phase, the formation of highly protonated LLZO during ball milling was identified as the most critical step. It was shown that the addition of minimal amounts of Li2CO3 during wet milling effectively suppresses LLZO protonation and ensure the effectiveness of relithiation during subsequent sintering. Using this modified method, flat LLZO separators with a relative density of 95.3 % were prepared in a simplified process with a significantly reduced excess lithium of only 5 mol % with respect to the stoichiometric LLZO, exhibiting an ionic conductivity of 0.18 mS cm−1 at room temperature and a critical current density of 1 mA cm−2 at 60 °C for lithium stripping/plating.
AB - Ceramic membranes made of garnet Li7Zr3La2O12 (LLZO) are promising separators for lithium metal batteries because they are chemically stable to lithium metal and can resist the growth of lithium dendrites. Free-standing garnet separators can be produced on a large scale using tape casting and sintering slurries containing LLZO powder, but the quality of the separators is severely compromized by the protonation of the moisture-sensitive LLZO during processing and the irreversible loss of lithium during sintering. In this work, an approach is presented to mitigate the degradation of the LLZO and produce high quality separators using Li2CO3 as a source of excess lithium. By systematically investigating the effects of Li2CO3 addition during the different steps of the tape casting process and the intricate relationship between the protonation and relithiation of LLZO phase, the formation of highly protonated LLZO during ball milling was identified as the most critical step. It was shown that the addition of minimal amounts of Li2CO3 during wet milling effectively suppresses LLZO protonation and ensure the effectiveness of relithiation during subsequent sintering. Using this modified method, flat LLZO separators with a relative density of 95.3 % were prepared in a simplified process with a significantly reduced excess lithium of only 5 mol % with respect to the stoichiometric LLZO, exhibiting an ionic conductivity of 0.18 mS cm−1 at room temperature and a critical current density of 1 mA cm−2 at 60 °C for lithium stripping/plating.
KW - Lithium loss
KW - LLZO
KW - Protonation, Sintering
KW - Solid-state batteries
KW - Tape-casting
UR - http://www.scopus.com/inward/record.url?scp=85196636576&partnerID=8YFLogxK
U2 - 10.1016/j.ensm.2024.103487
DO - 10.1016/j.ensm.2024.103487
M3 - Article
AN - SCOPUS:85196636576
SN - 2405-8297
VL - 71
JO - Energy Storage Materials
JF - Energy Storage Materials
M1 - 103487
ER -