Oral Room Temperature synthesized Graphene/MOPOF Nanocomposites for Low-cost Li Battery Cathodes

Abstract

Lithium ion batteries (LIBs) are the best available technology today to push forward the production of eco-friendly electricvehicles (EVs) to reduce the emission of CO2 into the atmosphere. In addition, they are promising for efficient utilization ofrenewable energy sources which needs to be stored for usage. The transformation from conventional vehicles run by fossil fuels tobattery powered EVs are mainly hindered by the high upfront price of the EVs which is mainly due to the high cost of the batterypacks used in these vehicles. Hence, cost reduction of LIBs is one of the major strategies to bring forth the EVs to compete in themarket with their gasoline counterparts. Cathode materials account for more than 40% of the total cost of LIBs and hence the costreduction should primarily focus on alternative low cost cathode materials. In this work, Graphene/ MOPOF (Metal OrganophosphateOpen Framework) nanocomposites, G/K2[(VO)2(HPO4)2(C2O4)] with ~4 V of operation has been developed by a cost effective roomtemperature synthesis that eliminates any expensive post-synthetic treatments at high temperature and devoid of inert atmosphereslike Ar/Ar-H2. Though the pristine MOPOF material can undergo reversible lithium storage, it encounter capacity fading due tointrinsic poor conductivity. Enhanced lithium cycling with minimal capacity fading was witnessed with the graphene nanocompositeowing to the increased electronic conductivity and enhanced Li diffusivity. GITT studies to examine the Li ion conduction in thematerial revealed the good Li ion diffusion coefficients in the framework, which are of the order of some layered oxide cathodes.