Lignocellulosic Biomass For Carbon Materials Applied In Supercapacitor

Lignocellulosic biomass is a renewable,widely available and.easily accessible resource,the high-value use of this natural resource can alleviate the current demand for energy,which is important for basic researches and applications.This work focus on the carbon materials prepared from lignocellulosic biomass and use them as electrode materials for supercapacitor.1.To make full use lignocellulosic biomass resources,comprehensive utilization of this renewable energy resource was proposed.In this work,Amygdalus pedunculata shell served as typical lignocellulosic biomass was used for ethanol production and activated carbon preparation,and the maximum ethanol yield 0.0158 g g-1 and activated carbon with maximum BET surface 2059 m2 g-1 were obtained.Additionally,the porous carbon was systematically characterized and applied as electrode material for supercapacitor which exhibits high specific capacitance of 358.4 F g-1 at a current density of 0.5 A g-1.After 1000 cycles,the capacitor still exhibited a stable performance with capacitance retention of 86.3%at a current density of 5 A g-1.The conversion of Amygdalus pedunculata shell to bioethanol and activated carbon applied as electrode material in high performance supercapacitor offers significant potentials for comprehensive utilization of lignocellulosic biomass.2.Porous graphene has been intensively investigated as a promising candidate for energy conversion and storage.While,industrialization with low cost as well as complicated synthesis procedure remains a major challenge in this field.Herein,a one-step and green methodology for porous graphene preparation from biomass was presented.It is,for the first time,observed that the resultant carbons change from activated carbon to porous graphene when the mass ratio of CaO/biomass is increased from low mass ratio to high ratio.The porous graphene was systematically characterized and employed as an electrode material for supercapacitor which exhibits a capacitance of 136 F g-1 at 1 A g-1 and maintains at 105 F g-1 even at an ultra-high discharge rate of 100 A g-1.Furthermore,a superior cycling stability with 97%capacitance is remained even after 10000 charging/discharging cycles at a high current density of 10 A g-1 This work provides new perspectives for the development of porous graphene from biomass in general,which shows potential prospects not only for fundamental research,but also for industrial applications.3.The mechanism of formation of graphene is explored in detail.It is identify that when the pyrolysis was performed at a low proportion,CaO mainly served as a catalyst for the pyrolysis of lignin and the evolved gases denoted as self-activation reagents,where self-activation with chromatographic column model is also proposed for the first time to understand the BET surface of porous carbon affected by the nitrogen flow rates.As the proportion of CaO/APS was increased to high proportion,CaO not only served as a catalyst but was also the template for graphene deposition.