Premium
Revealing the Thermal Safety of Prussian Blue Cathode for Safer Nonaqueous Batteries
Author(s) -
Li Zheng,
Dadsetan Mehran,
Gao Junxian,
Zhang Sensen,
Cai Lirong,
Naseri Ali,
JimenezCastaneda Martha E.,
Filley Timothy,
Miller Jeffrey T.,
Thomson Murray J.,
Pol Vilas G.
Publication year - 2021
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202101764
Subject(s) - thermal runaway , prussian blue , cathode , materials science , raman spectroscopy , x ray photoelectron spectroscopy , chemical engineering , electrochemistry , nanotechnology , battery (electricity) , electrode , chemistry , power (physics) , physics , quantum mechanics , optics , engineering
Prussian blue analogs (PBAs) are promising cathode materials for many next‐generation metal‐ion batteries due to their exceptional electrochemical performance. Their oxygen‐free structure avoids a common battery thermal runaway pathway which requires O 2 liberation. Herein, the thermal runaway mechanisms of PBAs are studied from the level of material and full cell in nonaqueous sodium‐ and potassium‐ion batteries (SIBs and KIBs). Their hidden safety issue and a novel runaway mechanism that requires no oxygen evolution are identified. The cyanide groups are released (≈51.4 wt%) as toxic cyanides above 200 °C, which also exothermically react with the electrolyte and cause the runaway. The cyanide gas generation mechanism is proposed as cathode hydrolytic disproportionation by Raman spectroscopy, X‐ray photoelectron spectroscopy, in situ environmental transmission electron microscopy, and operando synchrotron X‐ray diffraction studies. In addition, full‐cell level calorimetric studies reveal mitigated heat generation but lower initiation temperature of runaway from such SIBs and KIBs than conventional LiCoO 2 –graphite system. These results change how PBA materials are evaluated from a safety standpoint, suggesting that they cannot be regarded as safe cathodes. They also indicate the correlations between thermal safety and their crystal defects or trapped water content. The proposed thermal runaway mechanism provides insights to assist in the building of safer next‐generation batteries.