Self-discharge study of lignin/graphite hybrid material electrodes

Lignin has been proposed as electricity storage materials due to the redox activity of quinone (Q) and hydroquinone (QH(2)) groups, which can be formed in lignin. Scalable and low-cost lignosulfonate (LS)/graphite hybrid material electrodes have been developed. It is important to investigate the self discharge mechanism for these electrodes since a high self-discharge rate was observed, which results in loss of energy density and power density. In this work, self-discharge measurements and models are applied to clarify the self-discharge mechanism of the LS/graphite electrodes. A combination of diffusion controlled, activation controlled and charge equilibration mechanisms are indicated during the self discharge process at different charging voltages, due to the faradaic reactions of the Q/QH(2) confined in the electrodes. Our work contributes deeper understanding of the structure and the self-discharge mechanisms of the biopolymer/graphite hybrid electrodes. (C) 2021 The Author(s). Published by Elsevier Ltd.

Automated summary

The study proposes lignin as electricity storage material due to the redox activity of quinone and hydroquinone groups. The research investigates the self-discharge mechanism of lignosulfonate/graphite electrodes, revealing diffusion controlled, activation controlled, and charge equilibration mechanisms during self-discharge at different charging voltages. This work contributes to a deeper understanding of the structure and self-discharge mechanisms of biopolymer/graphite hybrid electrodes.