Abstract

The hybrid Fe-Li2TP structure is constructed from waste polyethylene terephthalate (w-PET) derived dilithium terephthalate (Li2TP) and conventional Fe2O3 by hydrothermal reaction. It is being studied for both anode and cathode for LIBs. As an anode, it exhibits a reversible capacity of 505 mAh/g after 100th cycle at 1 C-rate with similar to 100 % coulombic efficiency (CE). In addition, as a cathode, it shows highly reversible charge/discharge capacities of 107.50/107.52 mAh/g after the 100th cycle at 0.1 C-rate with 100 % CE. Further, in the cathodic studies via galvanostatic intermittent titration technique (GITT), the average lithium diffusion (DLi+) coefficients are calculated to be 2.96 x 10(-10), 3.89 x 10(-10) cm(2) s(-1) and the electrical (mu) mobilities to be 5.86 x 10(11) m(2) V-1 s(-1), 1.12 x 10(11) m(2) V-1 s(-1) for charge and discharge pulses, respectively. The combined nano-rod and nanospherical morphologies reduce the diffusion length, and adding 10 % SWCNTs during electrode fabrication enhances the electronic conductivity. This organic-inorganic hybrid strategy of Fe-Li2TP strongly mitigates the electrode dissolution, reducing the structural strain and preventing electrolyte decomposition at higher voltage. Computational studies show an optimized Fe-Li2TP structure with a 2.7-fold lower band gap value (1.9040 eV) than the pristine Li2TP.