Reduction of Charge-Transfer Resistance via Artificial SEI Formation Using Electropolymerization of Borylated Thiophene Monomer on Graphite Anodes

Modification of electrode surface using borylated-thiophene monomer resulted in the formation of a pre-formed solid electrolyte interface (SEI). The obtained ready-to use anodes did not show any loss in capacity during the first few cycles of charging and discharging. Herein, we report the synthesis and utilization of boron containing monomer to form an artificial SEI to reduce the interfacial resistance at SEI. Electropolymerization was performed via two methods, i) pre-modification and ii) in-situ modification. After the modification of the anodes, modified electrodes showed increased capacities, reduced capacity fading effect, and reduced interfacial resistance. Charge-discharge characteristics of half-cell with borylated thiophene polymer over graphite was studied and compared with graphite without any modification and polythiophene coated graphite.