Use of poly[ionic liquid] as a conductive binder in lithium ion batteries

CHAUQUE, SUSANA; TORRESI, ROBERTO M.; CÁMARA, OSVALDO R.; CÁMARA, OSVALDO R.; OLIVA, FABIANA Y.; OLIVA, FABIANA Y.; CHAUQUE, SUSANA; TORRESI, ROBERTO M.

JOURNAL OF SOLID STATE ELECTROCHEMISTRY (PRINT)

SPRINGER

Lugar: Berlin; Año: 2018 p. 1 - 8

1432-8488

In the present work, we studied the performance of different new binders based on poly[ionic liquids] (POILs) using a wellknownnegative electrode material such as Li4Ti5O12 (LTO) compound and ionic liquids (ILs) as solvents. We used an ILformed by Pip1,4Tf2N with N-butyl-N-methyl piperidinium (Pip1,4) as the cation and bis(trifluoromethanesulfonyl)imide(Tf2N−) as the anion. We tested two POILs as binders, composed of either LiTf2N, Pip1,4Tf2N, and PVDF orpoly[diallyldimethylammonium]Tf2N (PDDA) as the polymer precursors (PVDF-IL and PDDA-IL, respectively). The bestLi+ transport number as well as the smallest contact angle (electrolyte membrane) was obtained for the PDDA-IL polymer.The swelling effect better facilitates impregnation than the other polymers. The LTO/PDDA-IL combination showed the bestspecific capacity, 70 mAh g−1, and a stable prolonged cycling. We identified the TiIV/TiIII redox reversible processes bycyclic voltammetry experiments and the differential capacity profiles. Additionally, we measured the Li+ diffusion coefficientto be approximately 10−12 cm2 s−1. When different binders and IL-solvents are employed in a typical LTO cell, wedemonstrated that the factors that determine cell performance are the ionic conductivity and the swelling effect.