Please how can i prepare my electrolyte with respect to the amount of solvent. For example how much solvent is required to prepare 3M of LPF6 lithium salt with EC/EMC (1:2 v/v) solvent?
To get 3M, you'll have to calculate a weight of salt into a volume of solvent. Take the molar weight of the LiPF6, triple it, and that's how much salt you'd need for 3M in one litre of solvents. Assuming you're making less than a litre, divide accordingly.