Hello,

higher salt concentration will decrease the conductivity and increase the viscosity of the electrolyte.

(Fig.2: http://www.sciencedirect.com/science/article/pii/S0378775315008824)

This will lead to higher polarization while cycling, in the end you will end up with lower capacities and a lower power capability of your cell in comparison to 1M electrolytes. 

Moreover, due to the viscosity increase the wetting behavior might be influenced. 

Other effects are concerning your counter electrode, in case you are using graphite the higher salt concentration might impact the SEI formation. If you are using Li-metal electrodes the higher salt concentration might help to decrease high surface area lithium (dendritic) formations, as recent publication suggest. 

I hope that helps your investigation.

Thank you so much, Alex sir for ans.

Dear Hari Raj,

The following link will give you some idea.....

http://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.6b01474

Dear Natarajan,Thank

Thank You sir for your suggestion.