Towards safer sodium-ion batteries via organic solvent/ionic liquid based hybrid electrolytes

JOURNAL OF POWER SOURCES

卷:324

Article

Monti, Damien^1,2  Ponrouch, Alexandre^2,3  Rosa Palacin, M.^2,3  Johansson, Patrik^1,3 

[1] Chalmers Univ Technol, Dept Phys, SE-41296 Gothenburg, Sweden

[2] Inst Ciencia Mat Barcelona ICMAB CSIC, Campus UAB, E-08193 Bellaterra, Catalonia, Spain

[3] ALISTORE ERI European Res Inst, 33 Rue St Leu, F-80039 Amiens, France

关键词: Sodium-ion battery;    Ionic liquid;    Hybrid electrolytes;    Safety;    Imidazolium;    Pyrrolidinium;   

DOI  :  10.1016/j.jpowsour.2016.06.003

来源: Elsevier

【 摘 要 】

Hybrid electrolytes aimed at application in sodium-ion batteries (SIB) consisting of an organic solvent mixture (EC:PC) and different ionic liquids (ILs); EMImTFSI, BMImTFSI, and Pyr(13)TFSI, and with the NaTFSI salt providing the Na+ charge carriers have here been extensively studied. The physico-chemical and electrochemical characterisation includes ionic conductivity, viscosity, density, cation coordination and solvation, various safety measures, and electrochemical stability window (ESW). Hybrid electrolytes with 10-50% of IL content were found to have ionic conductivities on par with comparable organic solvent based electrolytes, but with highly enhanced safety properties. A systematic Raman spectroscopy study of the cation coordination and solvation before and after electrolyte safety tests by ignition suggest that IL cations and TESI remain stable when ignited while organic solvents are consumed. Finally, the solid electrolyte interphase (SEI) formed when using hybrid electrolytes has both better mechanical and electrochemical stability than the SEI derived from pure IL based electrolytes. For a half-cell with a hard carbon (HC) electrode and a hybrid electrolyte with a composition of 0.8 m NaTFSI in EC0.45:PC0.45:-Pyr(13)TESI(0.10) encouraging results were obtained for IL based electrolytes - ca. 182 mAhg(-1) at C/10 over 40 cycles. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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