A novel way for high value-added application of lignosulfonate: Producing lignosulfonate nanosheets/graphene ultrathin film electrodes for electrochemical capacitors.

In this paper, a novel way for high value-added application of lignosulfonate is presented. In this study, we use lignosulfonate nanosheets to fabricate a free-standing, binder-free, ultrathin and light-weight conductive film electrode via vacuum filtration method. The results show that LS is a promising candidate material for the preparation of electrochemical capacitor film electrode. It is worth mentioning that we use non-toxic, pollution-free aqueous solution (water) over organic solvents as the dispersion during the reductive graphene oxide (RGO) preparation process. The electrochemical measurements exhibit that the resistivity of lignosulfonate nanosheets/RGO (LNRGO) film electrode is 0.66 × 10 kΩ cm. The specific capacitance of the LNRGO film electrode is calculated to be 120 mF cm at the current density of 0.2 mA cm, which is approximately 6.67 times larger than that of RGO-water film electrode.