TY - JOUR
T1 - Insight on the failure mechanism of sn electrodes for sodium-ion batteries
T2 - Evidence of pore formation during sodiation and crack formation during desodiation
AU - Li, Tao
AU - Gulzar, Umair
AU - Bai, Xue
AU - Lenocini, Marco
AU - Prato, Mirko
AU - Aifantis, Katerina E.
AU - Capiglia, Claudio
AU - Proietti Zaccaria, Remo
N1 - Funding Information:
The authors would like to acknowledge the support from the 3315 project, grant Y70001DL01, Ningbo, China.
PY - 2019/1/28
Y1 - 2019/1/28
N2 - The development of Sn based anode materials for sodium ion batteries is mainly hindered by the limited understanding of sodiation/desodiation mechanisms inside the active material, which typically results in electrode damage. Herein, we report a post-mortem ex-situ scanning electron microscopic analysis of Sn thin film motivated by the intention to elucidate these structural mechanisms. Our results reveal for the first time that the surface of Sn electrode film becomes highly porous during sodiation with no presence of obvious cracks, a surprising result when compared to previous reports performed on Sn particles. Even more surprisingly, sequential ex-situ SEM observations demonstrate that, once the desodiation starts and reaches the second desodiation plateau (0.28 V), obvious cracks in the Sn film are instead observed along with porous islands of active material. These islands appear as aggregated particles which further split into smaller islands when the desodiation potential reaches its maximum value (2.0 V). Finally, for the first time, the experimental value of the sodium diffusion coefficient inside Sn was measured (3.9 × 10-14 cm2 s-1) using electrochemical impedance spectroscopy.
AB - The development of Sn based anode materials for sodium ion batteries is mainly hindered by the limited understanding of sodiation/desodiation mechanisms inside the active material, which typically results in electrode damage. Herein, we report a post-mortem ex-situ scanning electron microscopic analysis of Sn thin film motivated by the intention to elucidate these structural mechanisms. Our results reveal for the first time that the surface of Sn electrode film becomes highly porous during sodiation with no presence of obvious cracks, a surprising result when compared to previous reports performed on Sn particles. Even more surprisingly, sequential ex-situ SEM observations demonstrate that, once the desodiation starts and reaches the second desodiation plateau (0.28 V), obvious cracks in the Sn film are instead observed along with porous islands of active material. These islands appear as aggregated particles which further split into smaller islands when the desodiation potential reaches its maximum value (2.0 V). Finally, for the first time, the experimental value of the sodium diffusion coefficient inside Sn was measured (3.9 × 10-14 cm2 s-1) using electrochemical impedance spectroscopy.
KW - Diffusion coefficient
KW - Failure mechanism
KW - Impedance spectroscopy
KW - Mechanistic study
KW - Porous structure
KW - Sn anode
KW - Sodium-ion battery
UR - http://www.scopus.com/inward/record.url?scp=85065251708&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85065251708&partnerID=8YFLogxK
U2 - 10.1021/acsaem.8b01934
DO - 10.1021/acsaem.8b01934
M3 - Article
AN - SCOPUS:85065251708
VL - 2
SP - 860
EP - 866
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
SN - 2574-0962
IS - 1
ER -