Journal of Power Sources, Vol.347, 37-46, 2017
Jeffamine (R) based polymers as highly conductive polymer electrolytes and cathode binder materials for battery application
We report a simple synthesis route towards a new type of comb polymer material based on polyetheramines oligomer side chains (i.e., Jeffamine (R) compounds) and a poly(ethylene-alt-maleic anhydride) backbone. Reaction proceeds by imide ring formation through the NH2 group allowing for attachment of side chains. By taking advantage of the high configurational freedoms and flexibility of propylene oxide/ethylene oxide units (PO/EO) in Jeffamine (R) compounds, novel polymer matrices were obtained with good elastomeric properties. Fully amorphous solid polymer electrolytes (SPEs) based on lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and Jeffamine (R)-based polymer matrices show low glass transition temperatures around 40 degrees C, high ionic conductivities and good electrochemical stabilities. The ionic conductivities of Jeffamine-based SPEs (5.3 x 10(-4) S cm(-1) at 70 degrees C and 4.5 x 10(-5) S cm(-1) at room temperature) are higher than those of the conventional SPEs comprising of LiTFSI and linear poly(ethylene oxide) (PEO), due to the amorphous nature and the high concentration of mobile end-groups of the Jeffamine-based polymer matrices rather than the semi-crystalline PEO The feasibility of Jeffaminebased compounds in lithium metal batteries is further demonstrated by the implementation of Jeff amine-based polymer as a binder for cathode materials, and the stable cycling of Li vertical bar SPE vertical bar LiFePO4 and LiISPEIS cells using Jeffamine-based SPEs. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Polymer electrolyte;High ionic conductivity;Amorphous polymer;Jeffamine (R)-based compounds;Binders