| Title |
Lithiation/De-lithiation through Conversion and Alloying Reactions in MAPbBr3 Single Crystal Flake Li-ion Battery Anodes |
| Authors |
강인석(In-seok Kang); 박병남(Byoung-nam Park) |
| DOI |
https://doi.org/10.3365/KJMM.2022.60.11.845 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
perovskite; electrophotretic deposition; lithium ion battery; conversion reaction |
| Abstract |
In this study, single-crystalline methylammonium lead tribromide (MAPbBr3, CH3NH3PbBr3) flakes with a higher theoretical specific capacity than methylammonium lead iodide (MAPbI3, CH3NH3PbI3), the prototype of organic/inorganic hybrid perovskite, were synthesized by the inverse temperature crystallization method. The combination of the additive-free electrophoretic deposition (EPD) system and the single crystal fabrication method provided a fundamental understanding of the electrochemical properties associated with the lithium-ion storage mechanism in which the formation of the lithiated-phase (Lix:CH3NH3PbBr3) and the conversion reaction causes significant irreversible capacity, reducing battery cycle stability. The conversion reaction in MAPbBr3 was observed to be the main factor for high irreversible capacity, while the capacity due to the alloying reaction was more significant. The occurrence of the capacity due to the conversion reaction in the slurry system demonstrates that the additives worked as a buffer to relieve the stress associated with the formation of the lithiated phase, which was not observed in the MAPbBr3 EPD film. As part of an investigation of the active material/electrolyte in terms of cycling stability, the problem of structural instability was addressed by replacing the lithium salt and organic solvent that are components of the electrolyte. Our findings shed light on the intrinsic electrochemical properties of MAPbBr3 during lithiation/delithiation in the charging/discharging process, eliminating the complex effect caused by the MAPbBr3/additive mixture. Structural stability at the MAPbBr3/electrolyte interface was probed by varying the solvent and lithium salt.(Received 4 March, 2022; Accepted 1 September, 2022) |