High-Voltage Electrolytes Based on Adiponitrile for Li-Ion Batteries

Adiponitrile, , ADN, was evaluated as both a solvent and cosolvent in safer and more electrochemically stable electrolytes suitable for high energy and power density Li-ion batteries. An electrochemical investigation of its electrolyte solution with the , LiTFSI, salt showed a wide electrochemical window of vs . The high melting point and the incompatibility of ADN with graphite anode required the use of ethylene carbonate (EC) as a cosolvent. The resultant EC:ADN electrolyte solutions showed ionic conductivities reaching , viscosities of , and an improved resistance to aluminum corrosion up to , all at . Li-ion batteries incorporating graphite/ electrodes were assembled using EC:ADN electrolyte mixture containing LiTFSI and LiBOB as a cosalt, and discharge capacities of with very good capacity retention were obtained. AC impedance spectra of the batteries recorded as a function of charging and cycling indicated the presence of a stable solid electrolyte interface.