Electrochemical performance of Li-rich NMC cathode material using ionic liquid based blend polymer electrolyte for rechargeable Li-ion batteries

In this paper, synthesis of lithium rich nickel manganese cobalt oxide cathode material (Li1·2Ni0·6Mn0·1Co0·1O2) and ionic liquid (IL) based blend gel polymer electrolytes (BGPEs) are reported. Li1.2Ni0.6Mn0.1Co0.1O2 cathode material as well as BGPEs are prepared by solution combustion and solution casting technique, respectively. X-ray diffraction (XRD) technique clearly reveals that the cathode material is in pure phase, having well defined layered structure. Thermal, electrical and electrochemical properties of BGPEs are investigated by using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), impedance spectroscopy and linear sweep voltammetry (LSV). It is observed that 70 wt% IL containing BGPE provides maximum Li-ion conductivity (σLi+∼1.1 mS cm−1), thermal (∼250 °C) and electrochemical stability (∼4.3 V vs. Li/Li+). Electrochemical analysis of the cell (Li/70 wt% BGPE/Li1·2Ni0·6Mn0·1Co0·1O2) provides well defined redox peaks corresponding to Ni2+/Ni4+ and it delivers specific discharge capacity of 166 mAh g−1 at 0.1 C-rate and 97% efficiency upto 140 cycle.