Carbon nanosheets derived from reconstructed lignin for potassium and sodium storage with low voltage hysteresis

Autor: Xuehai Tan, Keren Jiang, Shengli Zhai, Zhi Li, Kenneth C. Cadien
Rok vydání: 2021
Předmět:
Zdroj: Nano Research. 14:4664-4673
ISSN: 1998-0000
1998-0124
DOI: 10.1007/s12274-021-3399-7
Popis: Lignin is the second most abundant and the only nature polymer rich in aromatic units. Although aromatic-unit-rich precursors often yield soft carbon after carbonization, the side chains in lignin crosslink with the aromatic units and form a rigid three-dimensional (3D) structure which eventually leads to hard carbons. Through a graphene oxide-catalyzed decomposition and repolymerization process, we successfully reconstructed lignin by partially tailoring the side chains. Compared to directly carbonized lignin, the carbonized reconstructed lignin possesses significantly fewer defects, 86% fewer oxygen-functionalities, 82% fewer micropores, and narrower interlayer space. These parameters can be tuned by the amount of catalysts (graphene oxide). When tested as anode for K-ion and Na-ion batteries, the carbonized reconstructed lignin delivers notably higher capacity at low-potential range (especially for Na-storage), shows much-improved performance at high current density, and most importantly, reduces voltage hysteresis between discharge and charge process by more than 50%, which is critical to the energy efficiency of the energy storage system. Our study reveals that the voltage hysteresis in K-storage is much severer than that in Na-storage for all samples. For practical K-ion battery applications, the voltage hysteresis deserves more attention in future electrode materials design and the reconstruct ion strategy introduced in this work provides potential low-cost solution.
Databáze: OpenAIRE
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