Interactions and Transport in Highly Concentrated LiTFSI-based Electrolytes
Artikel i vetenskaplig tidskrift, 2020

To elucidate what properties control and practically limit ion transport in highly concentrated electrolytes (HCEs), the viscosity, ionic conductivity, ionicity, and transport numbers were studied for nine model electrolytes and connected to the rate capability in Li-ion battery (LIB) cells. The electrolytes employed the LiTFSI salt in three molar ratio concentrations; 1 : 2, 1 : 4, and 1 : 16 (LiTFSI:X) vs. solvents (X) with different permittivities; tert-butyl methyl ether (MTBE), tetrahydrofuran (THF) and propylene carbonate (PC). While the low polarity MTBE creates liquid electrolytes, ion-pairing limits the ionic conductivity despite extremely low viscosities. For the less concentrated 1 : 16 LiTFSI:MTBE and 1 : 16 LiTFSI:THF electrolytes the ionic diffusivities decrease with increased temperature, a sign of aggregation, but still their ionic conductivities and LIB performance increase. In general, the low ionic conductivity and high viscosity both limit the use of HCEs in LIBs, and no compensating mechanism seems to be present.

transference

ionicity

rate capability

highly concentrated electrolyte

Författare

Viktor Nilsson

Centre national de la recherche scientifique (CNRS)

Uppsala universitet

Chalmers, Fysik, Materialfysik

Diana Bernin

Chalmers, Kemi och kemiteknik, Kemiteknik

D. Brandell

Uppsala universitet

K. Edstrom

Uppsala universitet

Centre national de la recherche scientifique (CNRS)

Patrik Johansson

Centre national de la recherche scientifique (CNRS)

Chalmers, Fysik, Materialfysik

ChemPhysChem

1439-4235 (ISSN) 1439-7641 (eISSN)

Vol. 21 11 1166-1176

Ämneskategorier

Keramteknik

Materialkemi

Annan kemiteknik

Annan fysik

DOI

10.1002/cphc.202000153

PubMed

32311226

Mer information

Senast uppdaterat

2022-04-06