Effect of structure of technical lignin on the electrochemical performance of lignin-derived porous carbon from K₂CO₃ activation

Abstract

Owing to its high aromaticity and carbon content, technical lignin as the by-product of chemical pulping and bio-refining industry can be converted into lignin-derived porous carbon (LPC) materials after activation, which is a promising strategy for high-value utilization. In particular, LPC with a higher surface area and graphitization will have a broad prospect as the electrode material for lithium-ion batteries (LIBs). However, the structure of technical lignin varies greatly due to its different industrial processes and botany sources, which remarkably affects the activation process and electrochemical properties of LPC. Herein, we study the effect of oxygen/carbon (O/C) ratio and molecular weight on the structure of LPC by exploring the effect of four kinds of technical lignin on K2CO3 activation. High O/C ratio can promote LPC to maintain a high specific surface area (SSA). High molecular weight and low O/C ratio were beneficial to increase the graphitization degree and keep the porous structure of LPC. The electrochemical performance evaluation showed that high graphitization and stable porous structure were beneficial for lithium-ion storage. Therefore, LPC from enzymatic hydrolysis lignin (EHL) had long cycle performance (490 mAh · g−1 at a current density of 400 mA · g−1) and excellent rate performance compared to lignin from chemical pulping.

Comparative investigation of the structural characteristics of tobacco stalk lignin during the DES and alkaline deconstruction toward sustainable materials

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Lignocellulosic biomass as sustainable feedstock and materials for power generation and energy storage

“…It indicates that lignin is a promising precursor for conductive carbon materials owing to its high aromaticity and carbon content. Qiu's group [296] recently reported ligninderived porous carbon (LPC) materials as electrode materials for LIBs from carbonization and K 2 CO 3 activation of different technical lignin sources and explored the effect of lignin resources on the structural, chemical, electrochemical properties of LPC. The results showed that a high molecular weight and low oxygen/carbon (O/C) ratio could benefit the graphitization degree but tended to cause a lower SSA.…”

A review on the effects of doping elements on the properties and applications of lignin-based carbon materials

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