Asymmetric capacitors using lignin-based hierarchical porous carbons

Abstract

Hierarchical porous carbons (HPC) were fabricated from lignin by hard template method using Beta and Y zeolites as templates. Textural properties were dictated by the hard template, obtaining a bi-modal pore size distribution with similar micropore sizes but different mesopore sizes. These HPCs provide a well-connected and developed porosity that show capacitance values near to 140 F g-1 in 1 M H2SO4 at 1 A g-1 and a capacitance retention of ca. 50% and 40% when the specific current is increased from 1 to 64 A g-1 for the Y and the Beta-based carbons, respectively. A symmetric capacitor working at 1.2 V with energy densities of 4.8 Wh kg-1 at 0.5 kW kg-1 has been obtained using the Beta-based HPC. Asymmetric in mass design allowed to operate the capacitor safely at 1.4 V, yielding an energy density of 7.3 Wh kg-1 at 0.5 kW kg-1 , a increase of 50% with respect to the symmetric configuration, while keeping a maximum power of 46 kW kg-1. This capacitor has an energy density comparable to that of a symmetric supercapacitor built using a commercial activated carbon of much higher porosity development, outperforming it in terms of energy, coulombic efficiencies and maximum power.

Green self-assembly synthesis of porous lignin-derived carbon quasi-nanosheets for high-performance supercapacitors

“…The energy density keeps 9.75 W h/kg at an ultrahigh power density of 6157.9 W/kg. These results indicate the PLC-650-2 based supercapacitor has outstanding energy-power characteristic even better than the reported lignin-or biomass-derived carbon-based supercapacitors [22,24,29,30,[52][53][54][55][56][57][58].…”

Porous Carbon Materials for Clean and Sustainable Energy

“…Three classes of porous materials are defined according to their pore sizes, namely microporous (pore size <2 nm), mesoporous (2 nm < pore size <50 nm), and macroporous (pore size >50 nm) [1]. Porous carbon materials of designed porosities and tunable properties, with high surface area, tunable porosity and surface property, good electrical conductivity, high chemical stability, have attracted intense interests in separation science and water purification, stationary phase materials, heterogeneous catalyst supports, sensing devices, and energy generation and storage applications (fuel cells, batteries, solar cells, and supercapacitors) [2][3][4][5][6].…”

Synthesis of sustainable lignin-derived mesoporous carbon for supercapacitors using a nano-sized MgO template coupled with Pluronic F127

“…2 Particularly, mesoporous carbons as electrode materials for supercapacitors show higher capacitance retention and excellent rate performance at high current density. [12][13][14][15] Preparing mesoporous carbons from sustainable lignin therefore has interested researchers worldwide, especially through nano-casting techniques, which commonly employ sacricial silica [16][17][18][19] or amphiphilic surfactants [20][21][22] to tailor the pore texture precisely.…”