Facile reduction of pseudo-carbonates: Promoting solid electrolyte interphases with dicyanoketene alkylene acetals in lithium-ion batteries

Coralie Forestier (1, 2, 3, 4) , Piotr Jankowski (5, 6) , Laura Coser (1, 2) , Grégory Gachot (1, 2) , Lucas Sannier (3) , Patrik Johansson (7, 6) , Michel Armand (1) , Sylvie Grugeon (1, 2) , Stephane Laruelle (1, 2)

1 LRCS - Laboratoire réactivité et chimie des solides - UMR CNRS 7314
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 Technocentre Renault [Guyancourt]
4 INERIS - Institut National de l'Environnement Industriel et des Risques
5 Warsaw University of Technology [Warsaw]
6 Department of Applied Physics, Chalmers University of Technology,
7 ALISTORE-ERI - Advanced Lithium Energy Storage Systems - ALISTORE-ERI

Dicyanoketene ethylene and propylene acetals, DCKEA and DCKPA respectively, have been investigated as electrolyte additives for Li-ion batteries. The purpose was to assess the changes in reduction behaviour and solid electrolyte interphase (SEI) passivation properties upon replacing the carbonyl group of ethylene carbonate (EC) and propylene carbonate (PC) solvents, respectively, by the slightly more electronegative and highly conjugated =C(CN)2 group. The experimental reduction potentials and the IR spectroscopy characterisation efforts were further supported by density functional theory (DFT) computations. The two additives were found to, in relatively small amount (0.5 wt%), provide beneficial effects on the capacity retention of 8 mAh cells cycled at 20 and 45°C. Moreover, the additives proved to enhance the thermal stability of the lithiated graphite/electrolyte interface, as deduced from DSC measurements.

Mots clés: Li-ion battery; SEI; additives; thermal runaway; DFT; dicyanoketene alkylene acetal

Domaines: Chimie inorganique; Matériaux

Coralie Forestier, Piotr Jankowski, Laura Coser, Grégory Gachot, Lucas Sannier, et al.. Facile reduction of pseudo-carbonates: Promoting solid electrolyte interphases with dicyanoketene alkylene acetals in lithium-ion batteries. Journal of Power Sources, 2016, 303, ⟨10.1016/j.jpowsour.2015.10.103⟩. ⟨hal-01234921⟩