Effect of diethyl carbonate solvent with fluorinated solvents as electrolyte system for anode free battery

Among different types of energy storage devices, anode free battery (AFB) is currently under extensive studies due to its simple configuration, cheap and enhanced energy density. However, a well-known problem like the generation of dendritic lithium and associated safety, poor coulombic efficiency plagues its practical implementations. Here 1.0 M lithium difluoro (oxalate) borate (LiDFOB) + 0.05 M lithium hexafluorophosphate in fluoroethylene carbonate/1,1,2,2-tetrafluoroethy1-2,2,3,3-tetrafluoropropyl ether/diethyl carbonate (FEC/TTE/DEC) electrolyte with (2:2:1 v/v/v ratio) delivers better electrochemical performance in both for Cu LiNi0.5Mn0.3Co0.2O2 (NMC532) as well as for Cu parallel to Li cells compared to FEC/TTE electrolyte with (2:3 v/v ratio). DEC contained and 2:3/FT electrolyte retains about 45% and 8% of the initial discharge capacity after 35 cycles respectively. The average coulombic efficiency of 98.07% for the DEC contained electrolyte after the 35th cycle, while only 92.23% obtained for 2:3/FT. Introducing of DEC results in the improvement of ionic conductivity, the formation of LiF-richer SEI and the formation of more Li on the anode side, which helps the cycle life of the battery. Designing electrolytes based on the synergetic effect from a solvent gives an insight into future pathways to bring solutions to the challenges of an AFB battery.