From Waste to Wealth: From Kraft Lignin to Free-standing Supercapacitors

Abstract

Pure eucalyptus Kraft lignin derived carbon fiber mats were produced based on a model workflow. It covers the preparation and characterization of the lignin precursor and the carbon materials and its testing in the final application (supercapacitor). Sequential solvent extraction was employed to produce a eucalyptus Kraft lignin precursor which could be electrospun into

High‐Performance Aqueous Supercapacitors Based on Biomass‐Derived Multiheteroatom Self‐Doped Porous Carbon Membranes

“…These values exceed those of the ones recently reported for aqueous SCs based on the biomass‐derived and other advanced carbon nanomaterials. [ 22–34 ] Furthermore, the cycling performance of the assembled SC was also evaluated using GCD measurments at a current density of 5 A g −1 . As shown in Figure 6d, 96.9% of capacitance can be retained with almost 100% Coulombic efficiency after the long‐term charging/discharging cycling of 100 000 cycles, indicating a superb cycling stability of the LCM‐900 electrode.…”

Hardwood versus softwood Kraft lignin – precursor-product relationships in the manufacture of porous carbon nanofibers for supercapacitors

“…The characterization methods used to obtain the values presented in the LPP are described in our previous publication. 26 The purity of both samples is very high, as indicated by the low ash and carbohydrate content. The low sulfur content (S in Fig.…”

“…The lignin was fractionated as described in our previous publications. 26,27 A sowood (pine/spruce mixture) Kra lignin was obtained from a LignoBoost process (Bäckhammer, Sweden). The lignin was dried at 80 C under vacuum for about 12 h. A sequential solvent extraction was used to produce a lignin fraction suitable for electrospinning.…”

“…The electrospinning procedure was similar to the one described in our previous publication. 26 Aer electrospinning, the as-spun lignin nanober mats were converted to carbon nanober mats by a two-step thermal treatment: (1) stabilization under an air ow (500 ml min À1 ) and (2) carbonization under N 2 ow (500 ml min À1 ) in a quartz tube (OD: 80 mm) furnace (OTF-1200X, MTI). The lignin nanober mats were stabilized at 190 C, 250 C, 310 C and 340 C for 15 min, where the ramp between RT and 50 C was 5 C min À1 and the one between 50 C and the corresponding stabilization temperature was 0.5 C min À1 .…”

“…25 Various sowood and hardwood lignin-derived carbon nanobers (LCNFs) were tested in supercapacitors operating in different electrolytes and cell congurations. [26][27][28][29][30] To date, a clear inference concerning the reasons for superior performance of one lignin compared with another is out of reach. Jeon et al started to address this issue by relating the molar mass of various lignin precursors with the creation of nanoporosity and the performance of the ligninbased carbon powder in aqueous acidic supercapacitors.…”